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Insulating under suspended wooden floor
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Martin Pentreath
Feb 14, 2012, 2:42:46 PM2/14/12
to
Hi all,
I'm finally getting round to a long-postponed project - insulating
under the living room floor.
It's a standard suspended timber floor on the ground floor of a
victorian terrace - two rooms knocked together. The boards a bare,
sanded, varnished, gappy, drafty, with a few rugs around. Under the
floor there is a void about two feet deep before you hit the soil.
There certainly seems to be adequate underfloor ventilation thanks to
airbricks, hence the fact that the room above is like a field in
Alaska.
I'm having some kingspan delivered tomorrow from the seconds place.
The plan is to wriggle underneath and wedge carefully cut strips of
kingspan in between the joists. Apart from increasing the themal
properties of the floor, draft-proofing is a major objective. So I'm
planning on using some expanding foam around the edges (applied from
the underside obviously). As to the gaps between the boards themselves
the quickest and easiest solution would be to use some very adhesive
tape, again applied from the underside. Any comments on this? I was
thinking of using something like this:
http://www.screwfix.com/p/duck-original-cloth-tape-black-50mm-x-50m/81035
Cheers!
Martin
I'm finally getting round to a long-postponed project - insulating
under the living room floor.
It's a standard suspended timber floor on the ground floor of a
victorian terrace - two rooms knocked together. The boards a bare,
sanded, varnished, gappy, drafty, with a few rugs around. Under the
floor there is a void about two feet deep before you hit the soil.
There certainly seems to be adequate underfloor ventilation thanks to
airbricks, hence the fact that the room above is like a field in
Alaska.
I'm having some kingspan delivered tomorrow from the seconds place.
The plan is to wriggle underneath and wedge carefully cut strips of
kingspan in between the joists. Apart from increasing the themal
properties of the floor, draft-proofing is a major objective. So I'm
planning on using some expanding foam around the edges (applied from
the underside obviously). As to the gaps between the boards themselves
the quickest and easiest solution would be to use some very adhesive
tape, again applied from the underside. Any comments on this? I was
thinking of using something like this:
http://www.screwfix.com/p/duck-original-cloth-tape-black-50mm-x-50m/81035
Cheers!
Martin
David WE Roberts
Feb 14, 2012, 2:53:34 PM2/14/12
to
"Martin Pentreath" <martin_p...@hotmail.com> wrote in message
news:8816dc35-ec7d-4f0f...@f14g2000yqe.googlegroups.com...
do more?
--
No plan survives contact with the enemy.
[Not even bunny]
Helmuth von Moltke the Elder
(\__/)
(='.'=)
(")_(")
robgraham
Feb 14, 2012, 5:55:05 PM2/14/12
to
On Feb 14, 7:42 pm, Martin Pentreath <martin_pentre...@hotmail.com>
wrote:
> thinking of using something like this:http://www.screwfix.com/p/duck-original-cloth-tape-black-50mm-x-50m/8...
>
> Cheers!
>
> Martin
I should really have done this rather a lot of years ago when I had to
clean out under our sitting room floor. Much the same sort of gap. I
suppose I could employ my son to do it, but the idea of going under
there now at 70 is just not realistic.
Enjoy !
Rob
wrote:
>
> Cheers!
>
> Martin
I should really have done this rather a lot of years ago when I had to
clean out under our sitting room floor. Much the same sort of gap. I
suppose I could employ my son to do it, but the idea of going under
there now at 70 is just not realistic.
Enjoy !
Rob
harry
Feb 15, 2012, 3:39:14 AM2/15/12
to
>
> Cheers!
>
> Martin
I have done this at my place.
You need to cut the foam about an inch too small and support it on
nails banged into the joists. This leaves space for the canned foam.
It also means you can use a can of foam up in one go and don't have
problems with the nozzle blocking up.
The foam expands a lot more on a fresh can and less as the can is
almost empty. Or maybe it comes out quicker. :-) You need to shove
the pipe right into the crack, it won't expand "uphill"when
unsupported.
Keep the stuff out off of your hair and hands, sticks like shit to a
blanket.
(Gloves and ratting cap)
The important thing is to miss nowhere with the foam. One little air
leak can negate all your work.
You need a lot more canned foam than you think. Cheapest place was
Screwfix when I did it.
mike
Feb 15, 2012, 4:12:58 AM2/15/12
to
>
> Cheers!
>
> Martin
I insulated the roof of a single story extension from underneath with
Kingspan between joists. Cut with a saw as accurately as possible, two
50mm layers, covered the joints between boards with duck tape. Tapped
thin wire nails into the sides of the joists to stop the Kingspan
slipping out. Some was such a tight fit that it wasn't a problem,
other bits with a warped joist and a slightly wonky cut line needed
it. Didn't bother trying to fill any edges between joists and boards
as I thought it was 95% there and considerably better than what was
there before.
Don't forget to wear goggles. Kingspan dust in your eyes feels like
sandpaper.
stuart noble
Feb 15, 2012, 6:04:13 AM2/15/12
to
> The important thing is to miss nowhere with the foam. One little air
> leak can negate all your work.
>
probably be 99% effective.
stuart noble
Feb 15, 2012, 6:09:28 AM2/15/12
to
> I insulated the roof of a single story extension from underneath with
> Kingspan between joists. Cut with a saw as accurately as possible, two
> 50mm layers, covered the joints between boards with duck tape. Tapped
> thin wire nails into the sides of the joists to stop the Kingspan
> slipping out. Some was such a tight fit that it wasn't a problem,
> other bits with a warped joist and a slightly wonky cut line needed
> it. Didn't bother trying to fill any edges between joists and boards
> as I thought it was 95% there and considerably better than what was
> there before.
>
the joist, you can run a saw against the other joist so that it's always
a tight fit.
Of course I only discovered this after much measuring and needless
faffing about
The Natural Philosopher
Feb 15, 2012, 6:12:23 AM2/15/12
to
ingress of cold air is the single dominant way of cooling a room once
insulation gets to a certain level.
In fact the single biggest thing you can do in old houses is to stop
draughts, even before you insulate.
The Natural Philosopher
Feb 15, 2012, 6:13:09 AM2/15/12
to
fred
Feb 15, 2012, 9:18:43 AM2/15/12
to
In article
<8816dc35-ec7d-4f0f...@f14g2000yqe.googlegroups.com>,
Martin Pentreath <martin_p...@hotmail.com> writes
I'd foam the sheet gaps too, you're going to be doing a lot of foaming
so doing those too isn't much of an overhead and you're then guaranteed
that it is all airtight.
As another has stated, it's all to easy to negate insulation with cold
airflow leaking to the warm side.
Consider how you're going to make the transitions between floor and
walls/dwarf walls to avoid a bridge for damp and avoid removing
essential from external lath and plaster walls.
--
fred
it's a ba-na-na . . . .
<8816dc35-ec7d-4f0f...@f14g2000yqe.googlegroups.com>,
Martin Pentreath <martin_p...@hotmail.com> writes
so doing those too isn't much of an overhead and you're then guaranteed
that it is all airtight.
As another has stated, it's all to easy to negate insulation with cold
airflow leaking to the warm side.
Consider how you're going to make the transitions between floor and
walls/dwarf walls to avoid a bridge for damp and avoid removing
essential from external lath and plaster walls.
--
fred
it's a ba-na-na . . . .
fred
Feb 15, 2012, 9:24:09 AM2/15/12
to
In article <FjWREtAD77OPFwkV@y.z>, fred <n...@for.mail> writes
Sorry, should read . . . and avoid removing essential _ventilation_ from
Martin Pentreath
Feb 15, 2012, 11:52:15 AM2/15/12
to
OK, thanks for all replies so far, especially from those with a bit of
previous.
My original intention only involved using foam to seal gaps around the
edge of the floor (from underneath). I had thought that taping the
gaps between floorboards would provide enough draft proofing there,
and then the kingspan would just need to be wedged and pinned between
joists to improve the thermal properties without the need for more
foam. Would this approach be inadequate then?
And if so, could someone explain a bit more clearly about using foam
in conjunction with the kingspan between the joists? Am I trying to
fill the void between the upper side of the kingspan and the underside
of the floorboards?Or just the gap between the edge of the kingspan
and the joists which it's sitting between?
I'm really not much looking forward to a couple of days of potholing
under my floor, but if I'm going down there I want to get it done
properly.
Cheers!
Martin
previous.
My original intention only involved using foam to seal gaps around the
edge of the floor (from underneath). I had thought that taping the
gaps between floorboards would provide enough draft proofing there,
and then the kingspan would just need to be wedged and pinned between
joists to improve the thermal properties without the need for more
foam. Would this approach be inadequate then?
And if so, could someone explain a bit more clearly about using foam
in conjunction with the kingspan between the joists? Am I trying to
fill the void between the upper side of the kingspan and the underside
of the floorboards?Or just the gap between the edge of the kingspan
and the joists which it's sitting between?
I'm really not much looking forward to a couple of days of potholing
under my floor, but if I'm going down there I want to get it done
properly.
Cheers!
Martin
harry
Feb 15, 2012, 12:00:50 PM2/15/12
to
On Feb 15, 4:52 pm, Martin Pentreath <martin_pentre...@hotmail.com>
wrote:
If you can find a tape that will stick on permanently. I haven't yet.
wrote:
The Natural Philosopher
Feb 15, 2012, 12:02:49 PM2/15/12
to
Martin Pentreath wrote:
> OK, thanks for all replies so far, especially from those with a bit of
> previous.
>
> My original intention only involved using foam to seal gaps around the
> edge of the floor (from underneath). I had thought that taping the
> gaps between floorboards would provide enough draft proofing there,
> and then the kingspan would just need to be wedged and pinned between
> joists to improve the thermal properties without the need for more
> foam. Would this approach be inadequate then?
>
> And if so, could someone explain a bit more clearly about using foam
> in conjunction with the kingspan between the joists? Am I trying to
> fill the void between the upper side of the kingspan and the underside
> of the floorboards?Or just the gap between the edge of the kingspan
> and the joists which it's sitting between?
> #
> OK, thanks for all replies so far, especially from those with a bit of
> previous.
>
> My original intention only involved using foam to seal gaps around the
> edge of the floor (from underneath). I had thought that taping the
> gaps between floorboards would provide enough draft proofing there,
> and then the kingspan would just need to be wedged and pinned between
> joists to improve the thermal properties without the need for more
> foam. Would this approach be inadequate then?
>
> And if so, could someone explain a bit more clearly about using foam
> in conjunction with the kingspan between the joists? Am I trying to
> fill the void between the upper side of the kingspan and the underside
> of the floorboards?Or just the gap between the edge of the kingspan
> and the joists which it's sitting between?
The latter. you dont want air bypassing the kingspan.
No pint in living in a insulated house if you leave the windows open....
> I'm really not much looking forward to a couple of days of potholing
> under my floor, but if I'm going down there I want to get it done
> properly.
>
> Cheers!
>
> Martin
fred
Feb 15, 2012, 12:18:58 PM2/15/12
to
In article
<f703b8a8-0c42-4d0a...@do4g2000vbb.googlegroups.com>,
Martin Pentreath <martin_p...@hotmail.com> writes
You're not looking to seal the gap between the celotex and the
floorboards boards, it's just not feasible, but you must ensure that air
cannot pass around the edge of the celotex to under the boards, negating
the insulation.
You are looking to:
1. Minimise the gap above the celotex (push up and wedge in place - cut
wooden wedges from batters, no need to nail as foam will fix it later)).
2. Seal all round the celotex boards (board to joist and board to board)
with foam so there is no way for cold air to pass the board to the warm
side.
3. At the end of a joist run you also need to seal the gap above the
board at the end (put a little foam on the top and side of the board at
the end and push it up into place, then wedge and foam around).
If you do this correctly then the insulation (plus joists) forms an air
tight barrier and you do not need to seal the gaps between the
floorboards.
I wouldn't use duct tape for any part of this, you need to pay decent
money to get long lasting sticky stuff and adhesion to old/dirty/rough
wood is not guaranteed long term.
If you buy a case of gun grade foam and a 15quid dispensing gun you will
be able to apply well controlled beads of foam as described above, it
makes the job really easy (quicker and easier than tape). As others have
said you actually want the celotex slightly undersize (5-10mm clear all
round) to make foaming easier.
<f703b8a8-0c42-4d0a...@do4g2000vbb.googlegroups.com>,
Martin Pentreath <martin_p...@hotmail.com> writes
floorboards boards, it's just not feasible, but you must ensure that air
cannot pass around the edge of the celotex to under the boards, negating
the insulation.
You are looking to:
1. Minimise the gap above the celotex (push up and wedge in place - cut
wooden wedges from batters, no need to nail as foam will fix it later)).
2. Seal all round the celotex boards (board to joist and board to board)
with foam so there is no way for cold air to pass the board to the warm
side.
3. At the end of a joist run you also need to seal the gap above the
board at the end (put a little foam on the top and side of the board at
the end and push it up into place, then wedge and foam around).
If you do this correctly then the insulation (plus joists) forms an air
tight barrier and you do not need to seal the gaps between the
floorboards.
I wouldn't use duct tape for any part of this, you need to pay decent
money to get long lasting sticky stuff and adhesion to old/dirty/rough
wood is not guaranteed long term.
If you buy a case of gun grade foam and a 15quid dispensing gun you will
be able to apply well controlled beads of foam as described above, it
makes the job really easy (quicker and easier than tape). As others have
said you actually want the celotex slightly undersize (5-10mm clear all
round) to make foaming easier.
Martin Pentreath
Feb 15, 2012, 12:35:05 PM2/15/12
to
On Feb 15, 5:18 pm, fred <n...@for.mail> wrote:
> In article
> <f703b8a8-0c42-4d0a-b3f4-25ad4a2d8...@do4g2000vbb.googlegroups.com>,
> Martin Pentreath <martin_pentre...@hotmail.com> writes
OK fantastic, thanks guys, as always just as well I asked in here
before going potholing.
As luck would have it Screwfix is offering their foam gun at clearance
price:
http://www.screwfix.com/p/design-pu-foam-gun/99927
Fred, you're saying a case of foam cans?? The room is a double one
(through lounge, as we used to say in 1978), floor area around 30 sq
m. I've never used foam before so I've no idea how far a 750ml can
goes, but do reckon I'll need 12 cans?
http://www.screwfix.com/p/no-nonsense-expanding-foam-for-gun-750ml-pk-of-12/83922
Cheers,
Martin
> In article
> <f703b8a8-0c42-4d0a-b3f4-25ad4a2d8...@do4g2000vbb.googlegroups.com>,
> Martin Pentreath <martin_pentre...@hotmail.com> writes
before going potholing.
As luck would have it Screwfix is offering their foam gun at clearance
price:
http://www.screwfix.com/p/design-pu-foam-gun/99927
Fred, you're saying a case of foam cans?? The room is a double one
(through lounge, as we used to say in 1978), floor area around 30 sq
m. I've never used foam before so I've no idea how far a 750ml can
goes, but do reckon I'll need 12 cans?
http://www.screwfix.com/p/no-nonsense-expanding-foam-for-gun-750ml-pk-of-12/83922
Cheers,
Martin
www.GymRatZ.co.uk
Feb 15, 2012, 1:22:16 PM2/15/12
to
On 15/02/2012 11:13, The Natural Philosopher wrote:
>> If you position the insulation over the joist gap, with one edge
>> against the joist, you can run a saw against the other joist so that
>> it's always a tight fit.
>> Of course I only discovered this after much measuring and needless
>> faffing about
>>
>
> you sill need to caulk or foam or tape the gaps.
I was going to say,
>> If you position the insulation over the joist gap, with one edge
>> against the joist, you can run a saw against the other joist so that
>> it's always a tight fit.
>> Of course I only discovered this after much measuring and needless
>> faffing about
>>
>
> you sill need to caulk or foam or tape the gaps.
When I did between joists for UFH I used whatever
caulk/silicon/stickystuff tubes I had lying around. Using "big Foam" to
fill a 2 or 3 mm gap is bound to end in tears...
Also... pinching the best bread knife from the kitchen draw is a much
better and less messy tool for cutting insulation to the joist. Smaller
gap, more of a precision fit. (less filling and less dust in your face.
:¬)
Pete
--
http://www.GymRatZ.co.uk - Fitness+Gym Equipment.
http://www.water-rower.co.uk
www.GymRatZ.co.uk
Feb 15, 2012, 1:31:29 PM2/15/12
to
On 14/02/2012 19:42, Martin Pentreath wrote:
> The plan is to wriggle underneath and wedge carefully cut strips of
> kingspan in between the joists. Apart from increasing the themal
> properties of the floor, draft-proofing is a major objective.
On reflection... What I might do would be not cut the sheets at all but
> The plan is to wriggle underneath and wedge carefully cut strips of
> kingspan in between the joists. Apart from increasing the themal
> properties of the floor, draft-proofing is a major objective.
fix them at 90 degrees to the joists. Then ductape the joins between
sheets.
Maybe cross-batten under the sheets to fix to joists with long screws or
nails, or long screws with some sort of roofing washer type thing to
hold them in place?
Got to be far easier than trying to get the sheets cut between joists
and sealed. The joist will still be "vented" into the room by the gaps
in the floorboards.
Just a thought open to criticism..
:¬)
http://www.bodysolid-gym-equipment.co.uk
http://www.trade-price-supplements.co.uk
http://www.water-rower.co.uk
fred
Feb 15, 2012, 2:23:28 PM2/15/12
to
In article
<4b238dc3-291c-4378...@1g2000yqv.googlegroups.com>,
Martin Pentreath <martin_p...@hotmail.com> writes
>
My guess, based on recently using approx half a can on filling a 5/6mm
gap over 12 linear metres is as follows:
Guessing that your space is approx 8x4m with joists on the short side at
600mm centres we have 13 spans of 4m giving 104 linear metres of joists,
2 seals per joist so 208 linear metres of gap fill plus a bit for the
butted ends between the sheets. Your 220m /my 12m x 0.5 can = 9 cans.
The bulk buy of a case saves a bit over singles so I'd go for that.
In my case I was using 2" celotex and looking to get a deep fill up the
side which was easy with the nozzle of the pro gun.
The gun deal looks good, don't forget a can of gun cleaner.
<4b238dc3-291c-4378...@1g2000yqv.googlegroups.com>,
Martin Pentreath <martin_p...@hotmail.com> writes
>
>OK fantastic, thanks guys, as always just as well I asked in here
>before going potholing.
>
>As luck would have it Screwfix is offering their foam gun at clearance
>price:
>http://www.screwfix.com/p/design-pu-foam-gun/99927
>
>Fred, you're saying a case of foam cans?? The room is a double one
>(through lounge, as we used to say in 1978), floor area around 30 sq
>m. I've never used foam before so I've no idea how far a 750ml can
>goes, but do reckon I'll need 12 cans?
>http://www.screwfix.com/p/no-nonsense-expanding-foam-for-gun-750ml-pk-of-
>12/83922
>
Well, that depends how big a gap you leave :-).
>before going potholing.
>
>As luck would have it Screwfix is offering their foam gun at clearance
>price:
>http://www.screwfix.com/p/design-pu-foam-gun/99927
>
>Fred, you're saying a case of foam cans?? The room is a double one
>(through lounge, as we used to say in 1978), floor area around 30 sq
>m. I've never used foam before so I've no idea how far a 750ml can
>goes, but do reckon I'll need 12 cans?
>http://www.screwfix.com/p/no-nonsense-expanding-foam-for-gun-750ml-pk-of-
>12/83922
>
My guess, based on recently using approx half a can on filling a 5/6mm
gap over 12 linear metres is as follows:
Guessing that your space is approx 8x4m with joists on the short side at
600mm centres we have 13 spans of 4m giving 104 linear metres of joists,
2 seals per joist so 208 linear metres of gap fill plus a bit for the
butted ends between the sheets. Your 220m /my 12m x 0.5 can = 9 cans.
The bulk buy of a case saves a bit over singles so I'd go for that.
In my case I was using 2" celotex and looking to get a deep fill up the
side which was easy with the nozzle of the pro gun.
The gun deal looks good, don't forget a can of gun cleaner.
mike
Feb 15, 2012, 4:39:42 PM2/15/12
to
On Feb 15, 11:12 am, The Natural Philosopher <t...@invalid.invalid>
wrote:
I can see that any airflow introduces some inefficiency but if the
slightest gap renders the whole exercise effectively useless (which
TNP and Harry appear to be saying), then what's the point of foaming
under the floorboards unless the rest of your house is hermetically
sealed? (...at which point you introduce potential condensation
problems.)
It seems to me that in the quest to screw the last few % efficiency
out of the Kingspan by foaming at the edges (or going from 1% to 100%
efficiency by TNP/Harry figures), you're creating a permanent mixed-
media nightmare of foam, Kingspan and wood (not unlike the cowboy
spray foam that used to be touted as a cure-all for old roofs) that's
going to come back and bite you on the ass when you need to lift a
floorboard to do some plumbing/electrics.
Gymratz' idea seems better than foam in terms of future-proofing
although it seems you then potentially get trapped pockets of (moist?)
air and possible dampness.
If you have to use foam to make this work, it seems you're perilously
close to having to admit that Kingspan (even with its superior U-
values) is not the right material in this instance and that you might
be better jamming Rockwool or some such between the joists.
Not trying to be confrontational or argumentative here but I'd like to
see the evidence for those figures --- and I think other factors are
being ignored in the quest for 100% insulation efficiency.
wrote:
slightest gap renders the whole exercise effectively useless (which
TNP and Harry appear to be saying), then what's the point of foaming
under the floorboards unless the rest of your house is hermetically
sealed? (...at which point you introduce potential condensation
problems.)
It seems to me that in the quest to screw the last few % efficiency
out of the Kingspan by foaming at the edges (or going from 1% to 100%
efficiency by TNP/Harry figures), you're creating a permanent mixed-
media nightmare of foam, Kingspan and wood (not unlike the cowboy
spray foam that used to be touted as a cure-all for old roofs) that's
going to come back and bite you on the ass when you need to lift a
floorboard to do some plumbing/electrics.
Gymratz' idea seems better than foam in terms of future-proofing
although it seems you then potentially get trapped pockets of (moist?)
air and possible dampness.
If you have to use foam to make this work, it seems you're perilously
close to having to admit that Kingspan (even with its superior U-
values) is not the right material in this instance and that you might
be better jamming Rockwool or some such between the joists.
Not trying to be confrontational or argumentative here but I'd like to
see the evidence for those figures --- and I think other factors are
being ignored in the quest for 100% insulation efficiency.
The Natural Philosopher
Feb 15, 2012, 5:06:55 PM2/15/12
to
taping OVER the joists to seal.
Then replace the floor
If you are bothered about foam use decorators' caulk or a mastic to seal.
And yes, houses these days ARE hermetically sealed with precise
ventilation introduced to the bare minimum.
> Gymratz' idea seems better than foam in terms of future-proofing
> although it seems you then potentially get trapped pockets of (moist?)
> air and possible dampness.
>
> If you have to use foam to make this work, it seems you're perilously
> close to having to admit that Kingspan (even with its superior U-
> values) is not the right material in this instance and that you might
> be better jamming Rockwool or some such between the joists.
>
losses are pure conduction and no internal convection tales place. If
you allow air movement its ruined
I got a huge increase in loft insulation when I boarded OVER the
rockwool. But only on WINDY days.
I doubled the comfort here when I caulked up the window frames to get
rid of the 1-2mm gaps.
> Not trying to be confrontational or argumentative here but I'd like to
> see the evidence for those figures --- and I think other factors are
> being ignored in the quest for 100% insulation efficiency.
If you'ld like a factoid, the rate of cooling of a heatsink is about
10-20 times greater when its fan blown, as to when its simply sitting
there using natural convection.
Windchill exists as an effect.
![george [dicegeorge]'s profile photo](http://lh3.googleusercontent.com/a-/ALV-UjVy3egmWxdo6kgdNwXDn-6EE54MDMuR9kO5wF-DhVhewlzxjNY=s40-c)
george [dicegeorge]
Feb 15, 2012, 5:30:01 PM2/15/12
to
On 15/02/12 18:31, www.GymRatZ.co.uk wrote:
> On 14/02/2012 19:42, Martin Pentreath wrote:
>
>> The plan is to wriggle underneath and wedge carefully cut strips of
>> kingspan in between the joists. Apart from increasing the themal
>> properties of the floor, draft-proofing is a major objective.
>
> On reflection... What I might do would be not cut the sheets at all but
> fix them at 90 degrees to the joists. Then ductape the joins between
> sheets.
> Maybe cross-batten under the sheets to fix to joists with long screws or
> nails, or long screws with some sort of roofing washer type thing to
> hold them in place?
> Got to be far easier than trying to get the sheets cut between joists
> and sealed. The joist will still be "vented" into the room by the gaps
> in the floorboards.
>
> Just a thought open to criticism..
> :Ź)
> On 14/02/2012 19:42, Martin Pentreath wrote:
>
>> The plan is to wriggle underneath and wedge carefully cut strips of
>> kingspan in between the joists. Apart from increasing the themal
>> properties of the floor, draft-proofing is a major objective.
>
> On reflection... What I might do would be not cut the sheets at all but
> fix them at 90 degrees to the joists. Then ductape the joins between
> sheets.
> Maybe cross-batten under the sheets to fix to joists with long screws or
> nails, or long screws with some sort of roofing washer type thing to
> hold them in place?
> Got to be far easier than trying to get the sheets cut between joists
> and sealed. The joist will still be "vented" into the room by the gaps
> in the floorboards.
>
> Just a thought open to criticism..
>
>
crawling under there and foaming upwards is going to be hell, youre
going to get foam in your face and everywhere!
are you sure you cant pull up the floorboards,then tape over the
kingspan and joistsd - or a plastic membrane? - then maybe put them
back with floorboard screws?
[g]
gremlin_95
Feb 15, 2012, 5:42:47 PM2/15/12
to
<snip>
Not sure, if this video will be of any help:
http://www.youtube.com/watch?v=AHBtOLeqZUc&feature=results_video&playnext=1&list=PL3505D03FA9BD27A7
--
David
Not sure, if this video will be of any help:
http://www.youtube.com/watch?v=AHBtOLeqZUc&feature=results_video&playnext=1&list=PL3505D03FA9BD27A7
--
David
george [dicegeorge]
Feb 15, 2012, 7:06:08 PM2/15/12
to
or tape.
So cold air will get up, due to pressure differences etc.
[g]
Andy Burns
Feb 16, 2012, 2:15:52 AM2/16/12
to
george [dicegeorge] wrote:
> On 15/02/12 22:42, gremlin_95 wrote:
>
>> http://www.youtube.com/watch?v=AHBtOLeqZUc&feature=results_video&playnext=1&list=PL3505D03FA9BD27A7
>
> They didnt seal the cracks between the celotex and the joists with foam
> or tape.
They had used tape along the celotex/celotex joins, but not along the
> On 15/02/12 22:42, gremlin_95 wrote:
>
>> http://www.youtube.com/watch?v=AHBtOLeqZUc&feature=results_video&playnext=1&list=PL3505D03FA9BD27A7
>
> They didnt seal the cracks between the celotex and the joists with foam
> or tape.
joist/celotex joins.
Harry
Feb 16, 2012, 3:28:20 AM2/16/12
to
On Feb 16, 7:15 am, Andy Burns <usenet.aug2...@adslpipe.co.uk> wrote:
> george [dicegeorge] wrote:
> > On 15/02/12 22:42, gremlin_95 wrote:
>
> >>http://www.youtube.com/watch?v=AHBtOLeqZUc&feature=results_video&play...
> george [dicegeorge] wrote:
> > On 15/02/12 22:42, gremlin_95 wrote:
>
>
> > They didnt seal the cracks between the celotex and the joists with foam
> > or tape.
>
> They had used tape along the celotex/celotex joins, but not along the
> joist/celotex joins.
Can I just suggest something? We are manufacturers of a special (non-
> > They didnt seal the cracks between the celotex and the joists with foam
> > or tape.
>
> They had used tape along the celotex/celotex joins, but not along the
> joist/celotex joins.
adhesive but elastic) draught seal for floorboards. These are designed
to stop all draughts around the skirting board and between
floorboards. To enjoy wooden floors you really do not need to either
crawl underneath the floor or lift the floors up (unless you feel that
the insulation property of the floorboards) is insufficient. The
installation of our seals takes about 2-3 hours per room max. We are
happy to send anybody interested free sample packs. Just email me or
send direct message.
Harry
mike
Feb 16, 2012, 3:40:59 AM2/16/12
to
On Feb 15, 10:06 pm, The Natural Philosopher <t...@invalid.invalid>
wrote:
hermetically sealed system is useless?
> The 'correct' method is to lift the floor and then lay the celotex
> taping OVER the joists to seal.
>
> Then replace the floor
But a selective focus on airflow fails to take into account real world
factors like the huge payback time of ripping up and reinstalling all
your floors and all attendant making good. Anything else is bound to
be a compromise.
> And yes, houses these days ARE hermetically sealed with precise
> ventilation introduced to the bare minimum.
In theory, perhaps. I suspect the reality of a Barratt box with
little or no building control oversight falls somewhat short. But
we're talking about retro-fitting to old properties here. If the all-
or-nothing theory is correct, the heat that can't get through the
foamed celotex is just going to make a bee-line for the open keyhole,
or straight through the cold bridge where the inner leaf blockwork was
turned to form the window reveal. But in reality, it's better to have
loft insulation and no cavity insulation than no insulation at all.
> Look te point of insulation is to trap air and stop it moving. So the
> losses are pure conduction and no internal convection tales place. If
> you allow air movement its ruined
Compromised perhaps, ruined no. If it were "ruined" there'd be no
point putting 4" of rockwool in the loft. There'd be no benefit to
putting another 10" on top because the tiny air leakage would entirely
negate the insulating effect. In reality, there's an incremental
increase.
> I got a huge increase in loft insulation when I boarded OVER the
> rockwool. But only on WINDY days.
The power of the wind. You'll be championing wind turbines next!
> I doubled the comfort here when I caulked up the window frames to get
> rid of the 1-2mm gaps.
You "doubled" the comfort? Well, I won't ask you the SI unit of
comfort ;-)
> > Not trying to be confrontational or argumentative here but I'd like to
> > see the evidence for those figures --- and I think other factors are
> > being ignored in the quest for 100% insulation efficiency.
>
> Air movement is a cold bridge, effectively.
>
> If you'ld like a factoid, the rate of cooling of a heatsink is about
> 10-20 times greater when its fan blown, as to when its simply sitting
> there using natural convection.
>
> Windchill exists as an effect.
Nobody disputes the facts. It's the implications and the figures that
are being debated.
It seems to me that this would be a preferable and more practical way
of insulating under an already installed floor even if thermal
efficiency is slightly less:
http://www.youtube.com/watch?v=lRQPDGGfdlk
wrote:
> mike wrote:
> >> No. Airgaps can utterly negate 99% of the insulation. DAMHIKT.
So, in the real world any kind of insulation other than in a
> >> No. Airgaps can utterly negate 99% of the insulation. DAMHIKT.
hermetically sealed system is useless?
> The 'correct' method is to lift the floor and then lay the celotex
> taping OVER the joists to seal.
>
> Then replace the floor
factors like the huge payback time of ripping up and reinstalling all
your floors and all attendant making good. Anything else is bound to
be a compromise.
> And yes, houses these days ARE hermetically sealed with precise
> ventilation introduced to the bare minimum.
little or no building control oversight falls somewhat short. But
we're talking about retro-fitting to old properties here. If the all-
or-nothing theory is correct, the heat that can't get through the
foamed celotex is just going to make a bee-line for the open keyhole,
or straight through the cold bridge where the inner leaf blockwork was
turned to form the window reveal. But in reality, it's better to have
loft insulation and no cavity insulation than no insulation at all.
> Look te point of insulation is to trap air and stop it moving. So the
> losses are pure conduction and no internal convection tales place. If
> you allow air movement its ruined
point putting 4" of rockwool in the loft. There'd be no benefit to
putting another 10" on top because the tiny air leakage would entirely
negate the insulating effect. In reality, there's an incremental
increase.
> I got a huge increase in loft insulation when I boarded OVER the
> rockwool. But only on WINDY days.
> I doubled the comfort here when I caulked up the window frames to get
> rid of the 1-2mm gaps.
comfort ;-)
> > Not trying to be confrontational or argumentative here but I'd like to
> > see the evidence for those figures --- and I think other factors are
> > being ignored in the quest for 100% insulation efficiency.
>
> Air movement is a cold bridge, effectively.
>
> If you'ld like a factoid, the rate of cooling of a heatsink is about
> 10-20 times greater when its fan blown, as to when its simply sitting
> there using natural convection.
>
> Windchill exists as an effect.
are being debated.
It seems to me that this would be a preferable and more practical way
of insulating under an already installed floor even if thermal
efficiency is slightly less:
http://www.youtube.com/watch?v=lRQPDGGfdlk
mike
Feb 16, 2012, 3:43:35 AM2/16/12
to
On Feb 16, 12:06 am, "george [dicegeorge]" <dicegeo...@hotmail.com>
wrote:
wrote:
> They didnt seal the cracks between the celotex and the joists with foam
> or tape.
>
> So cold air will get up, due to pressure differences etc.
What PSI is your house inflated to?
> or tape.
>
> So cold air will get up, due to pressure differences etc.
The Natural Philosopher
Feb 16, 2012, 5:28:00 AM2/16/12
to
mike wrote:
> On Feb 15, 10:06 pm, The Natural Philosopher <t...@invalid.invalid>
> wrote:
>> mike wrote:
>
>>>> No. Airgaps can utterly negate 99% of the insulation. DAMHIKT.
>
> So, in the real world any kind of insulation other than in a
> hermetically sealed system is useless?
>
>
more or less, yes.
> On Feb 15, 10:06 pm, The Natural Philosopher <t...@invalid.invalid>
> wrote:
>> mike wrote:
>
>>>> No. Airgaps can utterly negate 99% of the insulation. DAMHIKT.
>
> So, in the real world any kind of insulation other than in a
> hermetically sealed system is useless?
>
>
If there is any airflow.
>> The 'correct' method is to lift the floor and then lay the celotex
>> taping OVER the joists to seal.
>>
>> Then replace the floor
>
> But a selective focus on airflow fails to take into account real world
> factors like the huge payback time of ripping up and reinstalling all
> your floors and all attendant making good. Anything else is bound to
> be a compromise.
>
>
>> And yes, houses these days ARE hermetically sealed with precise
>> ventilation introduced to the bare minimum.
>
> In theory, perhaps. I suspect the reality of a Barratt box with
> little or no building control oversight falls somewhat short. But
> we're talking about retro-fitting to old properties here. If the all-
> or-nothing theory is correct, the heat that can't get through the
> foamed celotex is just going to make a bee-line for the open keyhole,
> or straight through the cold bridge where the inner leaf blockwork was
> turned to form the window reveal. But in reality, it's better to have
> loft insulation and no cavity insulation than no insulation at all.
>
>
>
>> Look te point of insulation is to trap air and stop it moving. So the
>> losses are pure conduction and no internal convection tales place. If
>> you allow air movement its ruined
>
> Compromised perhaps, ruined no. If it were "ruined" there'd be no
> point putting 4" of rockwool in the loft.
As I said on a windy day having the boarding over the insulation trebled
the effect of it. It was almost useless by itself. On a still day it was
fine of course.
There'd be no benefit to
> putting another 10" on top because the tiny air leakage would entirely
> negate the insulating effect. In reality, there's an incremental
> increase.
>
it works. The insulator is actually the air, and as long as it cant
move, it cant carry the heat away.
That why fluff and foam works - it traps the air. That's why you wear
windproof jackets over a sweater. The sweater alone is an insulator but
NOT with a a gale blowing through it.
Anything that allows air to move through or behind insulation makes that
bit of insulation pointless to have.
>
>> I got a huge increase in loft insulation when I boarded OVER the
>> rockwool. But only on WINDY days.
>
> The power of the wind. You'll be championing wind turbines next!
>
>
>> I doubled the comfort here when I caulked up the window frames to get
>> rid of the 1-2mm gaps.
>
>
> You "doubled" the comfort? Well, I won't ask you the SI unit of
> comfort ;-)
>
>
>>> Not trying to be confrontational or argumentative here but I'd like to
>>> see the evidence for those figures --- and I think other factors are
>>> being ignored in the quest for 100% insulation efficiency.
>> Air movement is a cold bridge, effectively.
>>
>> If you'ld like a factoid, the rate of cooling of a heatsink is about
>> 10-20 times greater when its fan blown, as to when its simply sitting
>> there using natural convection.
>>
>> Windchill exists as an effect.
>
> Nobody disputes the facts. It's the implications and the figures that
> are being debated.
>
> It seems to me that this would be a preferable and more practical way
> of insulating under an already installed floor even if thermal
> efficiency is slightly less:
>
waving - a sort of nod to eco bollox.
A suspended floor has a huge draught under it - or should. Its a cold
draught too..ground level air.
The floor has to be protected from that
> http://www.youtube.com/watch?v=lRQPDGGfdlk
gri...@gmail.com
Feb 16, 2012, 8:26:45 AM2/16/12
to
Kingspan) there is a demonstration of how leaks affect effectiveness.
The test box was built perfectly and a heater switched on inside and
readings taken. Arranging the panels so there were a few gaps of a
millimetre or so, the heat retention dropped by a min of 15% and up to
25% - quite significant.
Attention to detail pays off, it would seem; and the easiest way to do
that is during the installation phase, not bodging it later.
Andrew
Feb 16, 2012, 5:05:50 PM2/16/12
to
<gri...@gmail.com> wrote in message
news:0q0qj7tekml3p6ape...@4ax.com...
excessive effort Celotex/Kingspan solid sheets are the wrong material to
use. Rockwool may be less efficient, but if it will flexibly adapt to the
space between the joists and be slightly compressed against the floorboards
any air leaks can only have a localised effect, rather than compromising the
whole effort.
Andrew
fred
Feb 16, 2012, 6:06:22 PM2/16/12
to
In article <q5idnT1X7bAi4KDS...@brightview.com>, Andrew
<andrewn...@hotmail.co.uk> writes
Having done it both ways I'd use celotex next time, glass/rockwool is a
total ball-ache to use in that situation, the sealing of sheet
insulation is trivial in comparison the potential pitfalls of using
fibre.
<andrewn...@hotmail.co.uk> writes
total ball-ache to use in that situation, the sealing of sheet
insulation is trivial in comparison the potential pitfalls of using
fibre.
gri...@gmail.com
Feb 16, 2012, 8:08:29 PM2/16/12
to
On Thu, 16 Feb 2012 22:05:50 -0000, "Andrew"
<andrewn...@hotmail.co.uk> wrote:
>> Surprised me too - on one of the maker's sites (might be Celotex or
>> Kingspan) there is a demonstration of how leaks affect effectiveness.
>> The test box was built perfectly and a heater switched on inside and
>> readings taken. Arranging the panels so there were a few gaps of a
>> millimetre or so, the heat retention dropped by a min of 15% and up to
>> 25% - quite significant.
>> Attention to detail pays off, it would seem; and the easiest way to do
>> that is during the installation phase, not bodging it later.
>
>Or does this suggest that to insulate a floor to a moderate level without
>excessive effort Celotex/Kingspan solid sheets are the wrong material to
>use. Rockwool may be less efficient, but if it will flexibly adapt to the
>space between the joists and be slightly compressed against the floorboards
>any air leaks can only have a localised effect, rather than compromising the
>whole effort.
Horses for courses, I would say. My ceiling has sheepwool (lovely
<andrewn...@hotmail.co.uk> wrote:
>> Surprised me too - on one of the maker's sites (might be Celotex or
>> Kingspan) there is a demonstration of how leaks affect effectiveness.
>> The test box was built perfectly and a heater switched on inside and
>> readings taken. Arranging the panels so there were a few gaps of a
>> millimetre or so, the heat retention dropped by a min of 15% and up to
>> 25% - quite significant.
>> Attention to detail pays off, it would seem; and the easiest way to do
>> that is during the installation phase, not bodging it later.
>
>Or does this suggest that to insulate a floor to a moderate level without
>excessive effort Celotex/Kingspan solid sheets are the wrong material to
>use. Rockwool may be less efficient, but if it will flexibly adapt to the
>space between the joists and be slightly compressed against the floorboards
>any air leaks can only have a localised effect, rather than compromising the
>whole effort.
stuff, can't stand fibres up my chuff) and my walls are in the
beginning of having EPS/plasterboard stuck onto them. Both choices
were made for ease of handling, really.
I'll be paying close attention to the sealing of the EPS panels.
thirty-six
Feb 16, 2012, 8:31:46 PM2/16/12
to
On Feb 14, 7:42 pm, Martin Pentreath <martin_pentre...@hotmail.com>
wrote:
>
> Cheers!
>
> Martin
Plug the gaps between the floorboards using wood. Get a hand held IR
temperature sensor and after sunset search the room for the site of
the greatest heat loss. Put your attention to this first. Simple
glazing and leaky sash windows will be the site of greatest loss, so
refit the beading and add some secondary glazing. The sealed wooden
floor (close the gap between skirting and floor, will show the least
loss of heat,
wrote:
> Hi all,
>
> I'm finally getting round to a long-postponed project - insulating
> under the living room floor.
>
> It's a standard suspended timber floor on the ground floor of a
> victorian terrace - two rooms knocked together. The boards a bare,
> sanded, varnished, gappy, drafty, with a few rugs around. Under the
> floor there is a void about two feet deep before you hit the soil.
> There certainly seems to be adequate underfloor ventilation thanks to
> airbricks, hence the fact that the room above is like a field in
> Alaska.
>
> I'm having some kingspan delivered tomorrow from the seconds place.
>
> I'm finally getting round to a long-postponed project - insulating
> under the living room floor.
>
> It's a standard suspended timber floor on the ground floor of a
> victorian terrace - two rooms knocked together. The boards a bare,
> sanded, varnished, gappy, drafty, with a few rugs around. Under the
> floor there is a void about two feet deep before you hit the soil.
> There certainly seems to be adequate underfloor ventilation thanks to
> airbricks, hence the fact that the room above is like a field in
> Alaska.
>
> I'm having some kingspan delivered tomorrow from the seconds place.
> The plan is to wriggle underneath and wedge carefully cut strips of
> kingspan in between the joists. Apart from increasing the themal
> kingspan in between the joists. Apart from increasing the themal
> properties of the floor, draft-proofing is a major objective. So I'm
> planning on using some expanding foam around the edges (applied from
> the underside obviously). As to the gaps between the boards themselves
> the quickest and easiest solution would be to use some very adhesive
> tape, again applied from the underside. Any comments on this? I was
> thinking of using something like this:http://www.screwfix.com/p/duck-original-cloth-tape-black-50mm-x-50m/8...
> planning on using some expanding foam around the edges (applied from
> the underside obviously). As to the gaps between the boards themselves
> the quickest and easiest solution would be to use some very adhesive
> tape, again applied from the underside. Any comments on this? I was
>
> Cheers!
>
> Martin
Plug the gaps between the floorboards using wood. Get a hand held IR
temperature sensor and after sunset search the room for the site of
the greatest heat loss. Put your attention to this first. Simple
glazing and leaky sash windows will be the site of greatest loss, so
refit the beading and add some secondary glazing. The sealed wooden
floor (close the gap between skirting and floor, will show the least
loss of heat,
harry
Feb 17, 2012, 2:27:04 AM2/17/12
to
On Feb 16, 10:05 pm, "Andrew" <andrewnospam...@hotmail.co.uk> wrote:
> <grim...@gmail.com> wrote in message
> Andrew- Hide quoted text -
>
> - Show quoted text -
It falls out unless you devise ameans of holding it in. Also sags.
> <grim...@gmail.com> wrote in message
>
> - Show quoted text -
It falls out unless you devise ameans of holding it in. Also sags.
harry
Feb 17, 2012, 2:29:57 AM2/17/12
to
>
> - Show quoted text -
The best thing for the floorboard/skirting junction is the canned
> - Show quoted text -
foam. Goes right up the back of the skirting.
Gaps in floorboards, use silicon.
harry
Feb 17, 2012, 2:36:34 AM2/17/12
to
On Feb 14, 7:42 pm, Martin Pentreath <martin_pentre...@hotmail.com>
wrote:
> Hi all,
>
> I'm finally getting round to a long-postponed project - insulating
> under the living room floor.
>
> It's a standard suspended timber floor on the ground floor of a
> victorian terrace - two rooms knocked together. The boards a bare,
> sanded, varnished, gappy, drafty, with a few rugs around. Under the
> floor there is a void about two feet deep before you hit the soil.
> There certainly seems to be adequate underfloor ventilation thanks to
> airbricks, hence the fact that the room above is like a field in
> Alaska.
>
> I'm having some kingspan delivered tomorrow from the seconds place.
> The plan is to wriggle underneath and wedge carefully cut strips of
> kingspan in between the joists. Apart from increasing the themal
> properties of the floor, draft-proofing is a major objective. So I'm
> planning on using some expanding foam around the edges (applied from
> the underside obviously). As to the gaps between the boards themselves
> the quickest and easiest solution would be to use some very adhesive
> tape, again applied from the underside. Any comments on this? I was
> thinking of using something like this:http://www.screwfix.com/p/duck-original-cloth-tape-black-50mm-x-50m/8...
>
> Cheers!
>
> Martin
If you have any bits of foam left over. glue them the walls below/next
wrote:
> Hi all,
>
> I'm finally getting round to a long-postponed project - insulating
> under the living room floor.
>
> It's a standard suspended timber floor on the ground floor of a
> victorian terrace - two rooms knocked together. The boards a bare,
> sanded, varnished, gappy, drafty, with a few rugs around. Under the
> floor there is a void about two feet deep before you hit the soil.
> There certainly seems to be adequate underfloor ventilation thanks to
> airbricks, hence the fact that the room above is like a field in
> Alaska.
>
> I'm having some kingspan delivered tomorrow from the seconds place.
> The plan is to wriggle underneath and wedge carefully cut strips of
> kingspan in between the joists. Apart from increasing the themal
> properties of the floor, draft-proofing is a major objective. So I'm
> planning on using some expanding foam around the edges (applied from
> the underside obviously). As to the gaps between the boards themselves
> the quickest and easiest solution would be to use some very adhesive
> tape, again applied from the underside. Any comments on this? I was
> thinking of using something like this:http://www.screwfix.com/p/duck-original-cloth-tape-black-50mm-x-50m/8...
>
> Cheers!
>
> Martin
to the horizontal stuff. It reduces the thermal bridge offered by the
brickwork.
You need to hold it in postion temporarily with some nails hit into
the cement seams. Needs to be well sealed once again.
thirty-six
Feb 17, 2012, 7:02:03 AM2/17/12
to
harry
Feb 17, 2012, 12:29:31 PM2/17/12
to
>
> - Show quoted text -
I don't own a horse.
> - Show quoted text -
thirty-six
Feb 17, 2012, 5:32:52 PM2/17/12
to
Steve Walker
Feb 17, 2012, 6:33:10 PM2/17/12
to
On 14/02/2012 22:55, robgraham wrote:
> On Feb 14, 7:42 pm, Martin Pentreath<martin_pentre...@hotmail.com>
> wrote:
>> Hi all,
>>
>> I'm finally getting round to a long-postponed project - insulating
>> under the living room floor.
>>
>> It's a standard suspended timber floor on the ground floor of a
>> victorian terrace - two rooms knocked together. The boards a bare,
>> sanded, varnished, gappy, drafty, with a few rugs around. Under the
>> floor there is a void about two feet deep before you hit the soil.
>> There certainly seems to be adequate underfloor ventilation thanks to
>> airbricks, hence the fact that the room above is like a field in
>> Alaska.
>>
>> I'm having some kingspan delivered tomorrow from the seconds place.
>> The plan is to wriggle underneath and wedge carefully cut strips of
>> kingspan in between the joists. Apart from increasing the themal
>> properties of the floor, draft-proofing is a major objective. So I'm
>> planning on using some expanding foam around the edges (applied from
>> the underside obviously). As to the gaps between the boards themselves
>> the quickest and easiest solution would be to use some very adhesive
>> tape, again applied from the underside. Any comments on this? I was
>> thinking of using something like this:http://www.screwfix.com/p/duck-original-cloth-tape-black-50mm-x-50m/8...
>>
>> Cheers!
>>
>> Martin
>
> I should really have done this rather a lot of years ago when I had to
> On Feb 14, 7:42 pm, Martin Pentreath<martin_pentre...@hotmail.com>
> wrote:
>> Hi all,
>>
>> I'm finally getting round to a long-postponed project - insulating
>> under the living room floor.
>>
>> It's a standard suspended timber floor on the ground floor of a
>> victorian terrace - two rooms knocked together. The boards a bare,
>> sanded, varnished, gappy, drafty, with a few rugs around. Under the
>> floor there is a void about two feet deep before you hit the soil.
>> There certainly seems to be adequate underfloor ventilation thanks to
>> airbricks, hence the fact that the room above is like a field in
>> Alaska.
>>
>> I'm having some kingspan delivered tomorrow from the seconds place.
>> The plan is to wriggle underneath and wedge carefully cut strips of
>> kingspan in between the joists. Apart from increasing the themal
>> properties of the floor, draft-proofing is a major objective. So I'm
>> planning on using some expanding foam around the edges (applied from
>> the underside obviously). As to the gaps between the boards themselves
>> the quickest and easiest solution would be to use some very adhesive
>> tape, again applied from the underside. Any comments on this? I was
>> thinking of using something like this:http://www.screwfix.com/p/duck-original-cloth-tape-black-50mm-x-50m/8...
>>
>> Cheers!
>>
>> Martin
>
> clean out under our sitting room floor. Much the same sort of gap. I
> suppose I could employ my son to do it, but the idea of going under
> there now at 70 is just not realistic.
>
> Enjoy !
>
> Rob
I am in my forties, but have a very dodgy and painful knee; the gap
between the ground and the joists is also narrower than my shoulders, so
I can't turn over in most places; hence I phone my dad (aged 75) to get
under the floor! He is fit and well though.
SteveW
thirty-six
Feb 17, 2012, 7:10:50 PM2/17/12
to
On Feb 17, 11:33 pm, Steve Walker <st...@remove-this.walker-
My house is 1930s and I had to get between the joists to breathe when
I intalled the downstairs wiring and plumbing. I managed to get a
splinter in my arse for my troubles to maintain the floors's excellent
condition.
I intalled the downstairs wiring and plumbing. I managed to get a
splinter in my arse for my troubles to maintain the floors's excellent
condition.
harry
Feb 18, 2012, 3:28:52 AM2/18/12
to
>
> - Show quoted text -
He must be. It will be far easier to use my method (cut undersize and
> - Show quoted text -
canned foam).
You can measure and do all the cutting above the floor & pass the
pieces down.
Still a rotten time consuming job. But wasted unless you seal every
gap.
It's not possible to get a good enough fit be trying to be exact.
The stuff is incompressible and quite brittle., if you try to force it
into a gap, it just fractures.
mike
Feb 18, 2012, 4:36:10 AM2/18/12
to
On Feb 18, 8:28 am, harry <haroldhr...@aol.com> wrote:
> Still a rotten time consuming job. But wasted unless you seal every
> gap.
> It's not possible to get a good enough fit be trying to be exact.
> The stuff is incompressible and quite brittle., if you try to force it
> into a gap, it just fractures.
...which is surely an indication that it's not really the right
> Still a rotten time consuming job. But wasted unless you seal every
> gap.
> It's not possible to get a good enough fit be trying to be exact.
> The stuff is incompressible and quite brittle., if you try to force it
> into a gap, it just fractures.
material for the job and that something that friction fits would be
more suitable.
harry
Feb 18, 2012, 11:22:42 AM2/18/12
to
weaker. It's not all the same stuff from different manufacturers.
It relies on the foil facing for strength.
It offers the highest U values you can easily obtain.
You won't make it fit by cutting. especially under a floor in confined
spaces.
Why babble on with your theories? I'm talking practical now.
The Natural Philosopher
Feb 18, 2012, 12:31:16 PM2/18/12
to
mike
Feb 18, 2012, 5:42:47 PM2/18/12
to
that Kingspan could be made to fit exactly by cutting. I said that
"something that friction fits would be more suitable".
I appreciate that, on Planet Harry, that equates to something you have
to cut to the wrong size and then gob up with foam.
You're certainly talking something, Harry, but I don't think the word
is "practical".
harry
Feb 19, 2012, 3:49:43 AM2/19/12
to
>
> - Show quoted text -
It's practical because I have installed two truck loads of the stuff
> - Show quoted text -
in my place so I have tried all these things in all these situations.
The method I outline is the most practical because it's reasonably
quick and precludes leaks.
You will not exclude air leaks without some sort of gunge in the
joints. The foam expands to take up whatever space is available.
It cuts easily with a hand saw but is virtually impossible to cut
square, especially the thicker stuff . I suppose a bandsaw would do
it but it seems a bit overkill.
harry
Feb 19, 2012, 3:39:36 AM2/19/12
to
On Feb 18, 5:31 pm, The Natural Philosopher <t...@invalid.invalid>
wrote:
> Unusually, I agree with you.- Hide quoted text -
wrote:
>
> - Show quoted text -
So,,,we're big buddies now?
> - Show quoted text -
ARWadsworth
Feb 19, 2012, 7:34:13 AM2/19/12
to
mike wrote:
> On Feb 15, 11:12 am, The Natural Philosopher <t...@invalid.invalid>
> wrote:
> > once insulation gets to a certain level.
> >
> > In fact the single biggest thing you can do in old houses is to stop
> > draughts, even before you insulate.
>
> I can see that any airflow introduces some inefficiency but if the
> slightest gap renders the whole exercise effectively useless (which
> TNP and Harry appear to be saying), then what's the point of foaming
> under the floorboards unless the rest of your house is hermetically
> sealed? (...at which point you introduce potential condensation
> problems.)
Well an door with a missing cat flap still keeps the house warmer than a
house with an open door.......................
--
Adam
> On Feb 15, 11:12 am, The Natural Philosopher <t...@invalid.invalid>
> wrote:
> > stuart noble wrote:
> >
> > > > The important thing is to miss nowhere with the foam. One
> > > > little air leak can negate all your work.
> >
> > > I don't see that. Things are never perfect and 99% insulation will
> > > probably be 99% effective.
> >
> >
> > > > The important thing is to miss nowhere with the foam. One
> > > > little air leak can negate all your work.
> >
> > > I don't see that. Things are never perfect and 99% insulation will
> > > probably be 99% effective.
> >
> > No. Airgaps can utterly negate 99% of the insulation. DAMHIKT.
> >
> > ingress of cold air is the single dominant way of cooling a room
> >
> > once insulation gets to a certain level.
> >
> > In fact the single biggest thing you can do in old houses is to stop
> > draughts, even before you insulate.
>
> I can see that any airflow introduces some inefficiency but if the
> slightest gap renders the whole exercise effectively useless (which
> TNP and Harry appear to be saying), then what's the point of foaming
> under the floorboards unless the rest of your house is hermetically
> sealed? (...at which point you introduce potential condensation
> problems.)
Well an door with a missing cat flap still keeps the house warmer than a
house with an open door.......................
--
Adam
The Natural Philosopher
Feb 19, 2012, 7:53:14 AM2/19/12
to
The key thing is how fast the internal air is changed.
And its the same thing with insulated surfaces: how fast the air changes
BEHIND the insulation.
ARWadsworth
Feb 19, 2012, 8:14:41 AM2/19/12
to
The Natural Philosopher wrote:
> ARWadsworth wrote:
> > mike wrote:
> > > On Feb 15, 11:12 am, The Natural Philosopher
> > > <t...@invalid.invalid> wrote:
> > > > stuart noble wrote:
> > > >
> > > > > > The important thing is to miss nowhere with the foam. One
> > > > > > little air leak can negate all your work.
> > > > > I don't see that. Things are never perfect and 99% insulation
> > > > > will probably be 99% effective.
> > > > No. Airgaps can utterly negate 99% of the insulation. DAMHIKT.
> > > >
> > > > ingress of cold air is the single dominant way of cooling a room
> > > > once insulation gets to a certain level.
> > > >
> > > > In fact the single biggest thing you can do in old houses is to
> > > > stop draughts, even before you insulate.
> > > I can see that any airflow introduces some inefficiency but if the
> > > slightest gap renders the whole exercise effectively useless
> > > (which TNP and Harry appear to be saying), then what's the point
> > > of foaming under the floorboards unless the rest of your house is
> > > hermetically sealed? (...at which point you introduce potential
> > > condensation problems.)
> >
> > Well an door with a missing cat flap still keeps the house warmer
> > than a house with an open door.......................
> >
> in a howling gale it makes almost no difference.
I once went out with a girl called Gale. Once I was inside her she used to
> ARWadsworth wrote:
> > mike wrote:
> > > On Feb 15, 11:12 am, The Natural Philosopher
> > > <t...@invalid.invalid> wrote:
> > > > stuart noble wrote:
> > > >
> > > > > > The important thing is to miss nowhere with the foam. One
> > > > > > little air leak can negate all your work.
> > > > > I don't see that. Things are never perfect and 99% insulation
> > > > > will probably be 99% effective.
> > > > No. Airgaps can utterly negate 99% of the insulation. DAMHIKT.
> > > >
> > > > ingress of cold air is the single dominant way of cooling a room
> > > > once insulation gets to a certain level.
> > > >
> > > > In fact the single biggest thing you can do in old houses is to
> > > > stop draughts, even before you insulate.
> > > I can see that any airflow introduces some inefficiency but if the
> > > slightest gap renders the whole exercise effectively useless
> > > (which TNP and Harry appear to be saying), then what's the point
> > > of foaming under the floorboards unless the rest of your house is
> > > hermetically sealed? (...at which point you introduce potential
> > > condensation problems.)
> >
> > Well an door with a missing cat flap still keeps the house warmer
> > than a house with an open door.......................
> >
> in a howling gale it makes almost no difference.
howl.
--
Adam
harry
Feb 19, 2012, 1:57:50 PM2/19/12
to
On Feb 19, 12:34 pm, "ARWadsworth" <adamwadswo...@blueyonder.co.uk>
wrote:
> Adam- Hide quoted text -
wrote:
>
> - Show quoted text -
True. But pointless insulating the door.
> - Show quoted text -
gri...@gmail.com
Feb 19, 2012, 5:53:25 PM2/19/12
to
On Sun, 19 Feb 2012 13:14:41 -0000, "ARWadsworth"
<adamwa...@blueyonder.co.uk> wrote:
>> in a howling gale it makes almost no difference.
>
>I once went out with a girl called Gale. Once I was inside her she used to
>howl.
A seasoned-up hyena couldn't have been more obscener.
<adamwa...@blueyonder.co.uk> wrote:
>> in a howling gale it makes almost no difference.
>
>I once went out with a girl called Gale. Once I was inside her she used to
>howl.
Andy Burns
Feb 19, 2012, 5:56:52 PM2/19/12
to
Andrew
Feb 20, 2012, 2:04:16 PM2/20/12
to
"harry" <harol...@aol.com> wrote in message
news:f8f62fc8-883a-42a9...@n12g2000yqb.googlegroups.com...
cannot work in this way under the floor. I am interested in this thread
because I would like to insulate under the suspended floors in my bungalow -
provided it can be done without excessive effort. However there seems to be
no straightforward, standard way to insert this insulation - unlike say loft
or cavity wall insulation.
Andrew
mike
Feb 20, 2012, 5:21:45 PM2/20/12
to
On Feb 20, 7:04 pm, "Andrew" <andrewnospam...@hotmail.co.uk> wrote:
> So Rockwool works in the loft because gravity hold it in position- but
> cannot work in this way under the floor. I am interested in this thread
> because I would like to insulate under the suspended floors in my bungalow -
> provided it can be done without excessive effort. However there seems to be
> no straightforward, standard way to insert this insulation - unlike say loft
> or cavity wall insulation.
>
> Andrew
Seems the Yanks have a way:
> So Rockwool works in the loft because gravity hold it in position- but
> cannot work in this way under the floor. I am interested in this thread
> because I would like to insulate under the suspended floors in my bungalow -
> provided it can be done without excessive effort. However there seems to be
> no straightforward, standard way to insert this insulation - unlike say loft
> or cavity wall insulation.
>
> Andrew
http://www.youtube.com/watch?v=lRQPDGGfdlk
I've just replaced some old fibreglass insulation in the loft with
Rockwool and the Rockwool is a little more rigid (or a little less
flaccid) than fibreglass. It's also far less unpleasant to work with
-- less dusty, less itchy.
I think I might have a go putting some under the floorboards when I
can gird my loins for the potholing expedition.
george [dicegeorge]
Feb 21, 2012, 5:27:43 PM2/21/12
to
Re: Insulating under suspended wooden floor
http://www.youtube.com/watch?v=Dhi9DIjyCmc&feature=relmfu
recommends putting 6mm plastic sheets on the earth under the suspended
floor,
perhaps to stop moisture coming up from the ground?
[g]
http://www.youtube.com/watch?v=Dhi9DIjyCmc&feature=relmfu
recommends putting 6mm plastic sheets on the earth under the suspended
floor,
perhaps to stop moisture coming up from the ground?
[g]
thirty-six
Feb 21, 2012, 7:59:11 PM2/21/12
to
On Feb 21, 10:27 pm, "george [dicegeorge]" <dicegeo...@hotmail.com>
wrote:
> Re: Insulating under suspended wooden floorhttp://www.youtube.com/watch?v=Dhi9DIjyCmc&feature=relmfu
wrote:
> Re: Insulating under suspended wooden floorhttp://www.youtube.com/watch?v=Dhi9DIjyCmc&feature=relmfu
> recommends putting 6mm plastic sheets on the earth under the suspended
> floor,
> perhaps to stop moisture coming up from the ground?
>
> [g]
No, that's 6 mil. 0.006" or about 0.15mm
> floor,
> perhaps to stop moisture coming up from the ground?
>
> [g]
gri...@gmail.com
Feb 22, 2012, 8:41:19 AM2/22/12
to
over it will likely bugger it?
fred
Feb 24, 2012, 5:32:23 PM2/24/12
to
In article
<5d4c8441-e684-4e8c...@gi10g2000vbb.googlegroups.com>,
mike <mike...@yahoo.com> writes
'Push in lightning rods without compressing insulation', followed by
image of insulation compressed to half thickness by insertion of said
rod.
I'd only use non stretch mesh (chicken wire) to retain insulation if the
fill depth was greater than the joist depth by 20% so that inevitable
sag was compensated for.
I used a hardboard subfloor between joists here to support fibreglass
insulation but even then, only with 10% compression to avoid sag.
>I've just replaced some old fibreglass insulation in the loft with
>Rockwool and the Rockwool is a little more rigid (or a little less
>flaccid) than fibreglass. It's also far less unpleasant to work with
>-- less dusty, less itchy.
>
>I think I might have a go putting some under the floorboards when I
>can gird my loins for the potholing expedition.
>
I'd only use glass now for full joist plus insulation, for anything less
I'd used celotex seconds as previously described.
--
fred
it's a ba-na-na . . . .
<5d4c8441-e684-4e8c...@gi10g2000vbb.googlegroups.com>,
mike <mike...@yahoo.com> writes
>On Feb 20, 7:04 pm, "Andrew" <andrewnospam...@hotmail.co.uk> wrote:
>
>> So Rockwool works in the loft because gravity hold it in position- but
>> cannot work in this way under the floor. I am interested in this thread
>> because I would like to insulate under the suspended floors in my bungalow -
>> provided it can be done without excessive effort. However there seems to be
>> no straightforward, standard way to insert this insulation - unlike say loft
>> or cavity wall insulation.
>>
>> Andrew
>
>Seems the Yanks have a way:
>http://www.youtube.com/watch?v=lRQPDGGfdlk
>
Typical lazy, half arsed US approach, no guarantee of longevity.
>
>> So Rockwool works in the loft because gravity hold it in position- but
>> cannot work in this way under the floor. I am interested in this thread
>> because I would like to insulate under the suspended floors in my bungalow -
>> provided it can be done without excessive effort. However there seems to be
>> no straightforward, standard way to insert this insulation - unlike say loft
>> or cavity wall insulation.
>>
>> Andrew
>
>Seems the Yanks have a way:
>http://www.youtube.com/watch?v=lRQPDGGfdlk
>
'Push in lightning rods without compressing insulation', followed by
image of insulation compressed to half thickness by insertion of said
rod.
I'd only use non stretch mesh (chicken wire) to retain insulation if the
fill depth was greater than the joist depth by 20% so that inevitable
sag was compensated for.
I used a hardboard subfloor between joists here to support fibreglass
insulation but even then, only with 10% compression to avoid sag.
>I've just replaced some old fibreglass insulation in the loft with
>Rockwool and the Rockwool is a little more rigid (or a little less
>flaccid) than fibreglass. It's also far less unpleasant to work with
>-- less dusty, less itchy.
>
>I think I might have a go putting some under the floorboards when I
>can gird my loins for the potholing expedition.
>
I'd used celotex seconds as previously described.
--
fred
it's a ba-na-na . . . .
fred
Feb 24, 2012, 5:37:44 PM2/24/12
to
In article <ji15or$1aog$1...@news.enta.net>, george [dicegeorge]
<diceg...@hotmail.com> writes
Building regs here (Scotland) require the underfloor surface to be
sealed, tar in older times and weak mix mortar more recently. I'd expect
something similar doon sooth too.
<diceg...@hotmail.com> writes
sealed, tar in older times and weak mix mortar more recently. I'd expect
something similar doon sooth too.
The Natural Philosopher
Feb 25, 2012, 8:10:23 AM2/25/12
to
Now it happens that I have a block and beam suspended concrete floor
here, and yes, over the block and beam is a tough sheet of polythene,
and then some insulation, and then some screed.
But there is no requirement to actually stop the moisture at earth level.
That's what the ventilation is all about.
fred
Feb 25, 2012, 8:46:22 PM2/25/12
to
In article <jiamk0$mh3$1...@news.albasani.net>, The Natural Philosopher
<t...@invalid.invalid> writes
>Now it happens that I have a block and beam suspended concrete floor
>here, and yes, over the block and beam is a tough sheet of polythene,
>and then some insulation, and then some screed.
>
>But there is no requirement to actually stop the moisture at earth level.
>
It's been done on every underfloor I have come across up here. With the
effort and expense involved, I doubt they'd do it without it being a
requirement. Remember things are different up here eg. all roofs have
boarded sarking.
<t...@invalid.invalid> writes
>fred wrote:
>> In article <ji15or$1aog$1...@news.enta.net>, george [dicegeorge]
>> <diceg...@hotmail.com> writes
>>> Re: Insulating under suspended wooden floor
>>> http://www.youtube.com/watch?v=Dhi9DIjyCmc&feature=relmfu
>>> recommends putting 6mm plastic sheets on the earth under the suspended
>>> floor,
>>> perhaps to stop moisture coming up from the ground?
>>>
>> Building regs here (Scotland) require the underfloor surface to be
>> sealed, tar in older times and weak mix mortar more recently. I'd expect
>> something similar doon sooth too.
>
>that's for a none suspended floor.
>
No, this is on suspended floors.
>> In article <ji15or$1aog$1...@news.enta.net>, george [dicegeorge]
>> <diceg...@hotmail.com> writes
>>> Re: Insulating under suspended wooden floor
>>> http://www.youtube.com/watch?v=Dhi9DIjyCmc&feature=relmfu
>>> recommends putting 6mm plastic sheets on the earth under the suspended
>>> floor,
>>> perhaps to stop moisture coming up from the ground?
>>>
>> Building regs here (Scotland) require the underfloor surface to be
>> sealed, tar in older times and weak mix mortar more recently. I'd expect
>> something similar doon sooth too.
>
>that's for a none suspended floor.
>
>Now it happens that I have a block and beam suspended concrete floor
>here, and yes, over the block and beam is a tough sheet of polythene,
>and then some insulation, and then some screed.
>
>But there is no requirement to actually stop the moisture at earth level.
>
effort and expense involved, I doubt they'd do it without it being a
requirement. Remember things are different up here eg. all roofs have
boarded sarking.
gri...@gmail.com
Feb 26, 2012, 8:19:01 AM2/26/12
to
On Sun, 26 Feb 2012 01:46:22 +0000, fred <n...@for.mail> wrote:
>>> Building regs here (Scotland) require the underfloor surface to be
>>> sealed, tar in older times and weak mix mortar more recently. I'd expect
>>> something similar doon sooth too.
>>
>>that's for a none suspended floor.
>>
>No, this is on suspended floors.
Yes - every house I've seen under the floor of in Scotland had that.
>>> Building regs here (Scotland) require the underfloor surface to be
>>> sealed, tar in older times and weak mix mortar more recently. I'd expect
>>> something similar doon sooth too.
>>
>>that's for a none suspended floor.
>>
>No, this is on suspended floors.
I don't know when it was introduced, but certainly my '30s bungalow
had tar laid down on the ground underneath.
>>Now it happens that I have a block and beam suspended concrete floor
>>here, and yes, over the block and beam is a tough sheet of polythene,
>>and then some insulation, and then some screed.
>>
>>But there is no requirement to actually stop the moisture at earth level.
>>
>It's been done on every underfloor I have come across up here. With the
>effort and expense involved, I doubt they'd do it without it being a
>requirement. Remember things are different up here eg. all roofs have
>boarded sarking.
DIYDave34
Feb 26, 2012, 2:36:28 PM2/26/12
to
Not sure if it helps - but i asked these guys - as i am a real DIY
amateur!! these guys were really good. i asked them loads of stupid
questions and in the end got a bulk order of everything i needed!
as well as a few quick orders for things i had forgotten! really great
price and fast delivery
would definatly recommend - they seemed to know all the answers, or if
they were unsure they found out and rang me back!
'Loft Insulation | Insulated Plasterboard | Floor, Wall and Roof...'
(http://www.insulationplace.co.uk)
Hope this helps
Dave
--
DIYDave34
mike
Feb 26, 2012, 5:25:14 PM2/26/12
to
you pretend to be, how do you know the advice you were given was
sound? They could've sold you a tipper-load of rat shit and you'd've
been happy 'cause you're pig-shit thick and naive, aren't you?
Aren't you, Dave? Just a poor innocent little newbie dipping your toe
in the water to offer some hopefully helpful advice?
Well you'll be pleased to know, DIYDave34, that your posting was a
great help.
It means that everyone here will avoid trading with the
insulationplace, cookersandovens, paving place and cleverduck
bathrooms -- and any other front ends for Tippers Builders Merchants
that you've spammed forums about recently.
And you have been a busy little spammer haven't you, you fucking cunt,
Dave? You bought your garage insulation and your splashback from them
as well, didn't you? Yeah, right.
If insulationplace or Tippers or whatever you're calling yourself
today know as much about insulation as you do about spamming, you must
be the most shitehouse builders merchants in the UK.
Happy now, Tipper Dave? Did you get the attention you wanted?
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