We've got a bedroom above the garage in our eight year old house which
is always 5 deg C colder (or more) than the rest of the house on cold
days. The fact that the bedroom floor is always cold leads me to
believe the insulation requires significant improvement between the
garage ceiling and bedroom floor.
I've read these previous threads which seem sensible:
http://xrl.us/bg5jr (Link to groups.google.co.uk)
and this:
http://xrl.us/bg5jt (Link to www.diynot.com)
What I'd like to know is has anyone suffered with this cold room above
garage syndrome, improved the insulation, and actually fixed the
problem? If you have, can you state what you did and what materials
you used please? I can't pull up the flooring as we've just had new
carpet laid but would be prepared to pull down the plaster ceiling if
necessary.
Thanks in advance,
Jon
Mine has fibreglass (looks like regular loft insulation)
in the gap. There's probably around 6" -- certainly it's
most of the 8" (IIRC) height of the joists. (That's a 1990
house.)
My parents recently had a single storey flat roofed extension
insulated. (Built in 1964, originally just foil backed board
and strawboard roof as insulation. Strawboard had been
replaced with ply.) I wasn't there, but I understand
they took down a strip of plasterboard along the centre
of the room perpendicular to the joists, and slid more
solid fibreglass bats along above the ceiling to the
edges. Ceiling was then repaired and the room was to be
decorated anyway.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
Mine has always been warm even though the long wall is north facing
Ceiling of garage is 2 x half inch plasterboard to give required fire
protection ( built in 1991 to regs current at the time)
space between ceiling and floor above filled with 6" fibreglass
interior walls thermalite blocks cavity filled with rockwool bats
Ceiling of room standard plasterboard 6" fibreglass above boarded over for
storage
Tony
I'm not too worried about the finish as the ceiling is only in the
garage. The trouble is there is already some poor quality loft
insulation in the void and I would have to get that out first before
putting in the rockwool, which could be a problem.
Nice idea about cutting out a strip of plaster though and pushing in
the new insulation. Removing all the plasterboard will be very messy
and I don't fancy it at all, but it needs must ....
Thanks,
Jon
We changed mattress a while ago and the difference in warmth is amazing.
The one we got has a hefty layer of warm material where the old one
let a breeze through. I haven't used a winter weight duvet this winter -
at all.
The room itself might still freeze (ours is not over a garage) but that
is less of a problem when we are toasty warm in bed.
--
Rod
The room itself is used as a study so nobody sleeps in there, but it
would be nice if I could get the room to be the same temperature as
the rest of the house by insulating it better.
BTW, the removed strip straddled the nogins, so they could
push the bats up either side to both edges.
I wonder if the loose fill rockwool cavity insulation (the stuff that is
blown in) could be used in the same way to fill between the floors
would just be a few smallish holes in the ceiling to deal with
Tony
may be worth asking a company what they think
I have considered this option, but for it to work properly I'd still
need to remove the existing insulation which is in place which would
involve cutting plasterboard out. If I'm having to cut plasterboard
out, I might aswell use rockwool slabs as it would be more insulative.
I'm sure someone would be able to confirm or not though.
Thanks,
Jon
Have you considered putting a bit more heat into the room? Is the
radiator at the same temperature (in and out) as the others in the
house? Does it have a thermostatic valve, and if so, is it set and
working correctly? Could you put a suitably controlled larger radiator
in, or substitute a double for a single?
Depending on how long you intend to live there, and how much of the day
you need the room to be warm, it may even be more cost-effective than
buying lots of insulation. A quick look at the calculations for the
system I've just put in suggests that the most heat loss you could hope
to save would be perhaps a couple of hundred watts.
There, I've said it.
At least you say you've got a carpet in there, which will help: better
than a solid-copper-with fins-underneath floor, or whatever is
fashionable today.
--
Kevin Poole
**Use current month and year to reply (e.g. mar...@mainbeam.co.uk)***
> Is the
> radiator at the same temperature (in and out) as the others in the
> house?
Yes
> Does it have a thermostatic valve, and if so, is it set and
> working correctly?
Yes, and it works fine. The rad gets as hot as the rest in the house.
> Could you put a suitably controlled larger radiator
> in, or substitute a double for a single?
It's already a double. Larger rad = more load on boiler which is only
just the right size for a 4 bed house (cheap ass persimmon).
> Depending on how long you intend to live there, and how much of the day
> you need the room to be warm, it may even be more cost-effective than
> buying lots of insulation. A quick look at the calculations for the
> system I've just put in suggests that the most heat loss you could hope
> to save would be perhaps a couple of hundred watts.
You're not wrong. And I intend staying here for quite a while yet.
The floor will always be cold in the room as long as the lack of
insulation between the garage and the room above allows it. No matter
how much heat I throw in, the garage below will act as a heat sink.
Maybe I'd be better off insulating the garage. But the garage door has
so many gaping holes letting cold air in through the gap between the
frame that it'd not be cost effective either unless I changed the door
(expensive).
>
> There, I've said it.
>
> At least you say you've got a carpet in there, which will help: better
> than a solid-copper-with fins-underneath floor, or whatever is
> fashionable today.
I'm just looking for a sensible solution to the problem.
Thanks for your reply.
>> Could you put a suitably controlled larger radiator
>> in, or substitute a double for a single?
>
> It's already a double.
With fins?
> Larger rad = more load on boiler which is only
> just the right size for a 4 bed house (cheap ass persimmon).
>
Is the boiler really running flat out, firing continuously, even on a
very cold day? I'd be surprised if the builder had calculated it that
closely. Older boilers can often have their maximum gas rate tweaked
(within defined limits, of course). Is it at its maximum rate?
>> Depending on how long you intend to live there, and how much of the
>> day
>> you need the room to be warm, it may even be more cost-effective than
>> buying lots of insulation. A quick look at the calculations for the
>> system I've just put in suggests that the most heat loss you could
>> hope
>> to save would be perhaps a couple of hundred watts.
>
> You're not wrong. And I intend staying here for quite a while yet.
>
> The floor will always be cold in the room as long as the lack of
> insulation between the garage and the room above allows it. No matter
> how much heat I throw in, the garage below will act as a heat sink.
>
It's true that insulating the floor will raise the temperature of its
upper surface, but I'm suggesting it may not be enough to raise the room
temperature much. The world acts as a heat sink for your roof and
walls, too, but you design accordingly. The energy transferred through
the floor is a largely function of its area, its thermal resistance, and
the temperature difference between the room and the garage. The thermal
resistance is the sum of the resistance of the elements of the floor,
including the surface effect. Unless the garage has a howling gale
through it, your bedroom floor is therefore no different to the
suspended timber ground floors found in many houses.
So do the sums: you'll find a range of values suggested for the thermal
conductivity of suspended floors, but take a sensible stab at it, and
play with the effect of different values of added insulation. Then
compare the cost with that of providing extra heat input, even if you
have to use supplementary heating occasionally.
> Maybe I'd be better off insulating the garage. But the garage door has
> so many gaping holes letting cold air in through the gap between the
> frame that it'd not be cost effective either unless I changed the door
> (expensive).
>
Insulate it iff you want a warmer garage for other reasons. Even if
insulating it pushed its temperature up 5 degrees, it will only make
perhaps 100W difference to the heat loss from the room, so perhaps a
degree or two to the room temperature.
> >> > We've got a bedroom above the garage in our eight year old house
> >> > which
> >> > is always 5 deg C colder (or more) than the rest of the house on
> >> > cold
> >> > days. The fact that the bedroom floor is always cold leads me to
> >> > believe the insulation requires significant improvement between the
> >> > garage ceiling and bedroom floor.
>
> <snip>
>
> >> Could you put a suitably controlled larger radiator
> >> in, or substitute a double for a single?
>
> > It's already a double.
>
> With fins?
Yep, it has fins.
> > Larger rad = more load on boiler which is only
> > just the right size for a 4 bed house (cheap ass persimmon).
>
> Is the boiler really running flat out, firing continuously, even on a
> very cold day? I'd be surprised if the builder had calculated it that
> closely. Older boilers can often have their maximum gas rate tweaked
> (within defined limits, of course). Is it at its maximum rate?
Fair point, but the boiler already works hard to get the temperature
up. Thankfully the rest of the house is reasonably well insulated (as
you would like to expect for a house of this age) and the boiler will
not need to fire again for quite a while due to heatloss. I'm not
going to mess with the gas rate.
<snip>
> It's true that insulating the floor will raise the temperature of its
> upper surface, but I'm suggesting it may not be enough to raise the room
> temperature much. The world acts as a heat sink for your roof and
> walls, too, but you design accordingly.
I understand the basic physics of heat transfer and the fact that any
form of energy will want to take the path of least resistance to reach
a lower value. The most fundamental thing I also realise is that these
days, the houses which are bulk built by the big boys of the housing
estates like mine will only pay the minimum necessary to get a house
to stand up, pass the regs, and sell. That means using materials which
might be lesser to the ones we would choose.
>
> So do the sums:
<snip>
> Then
> compare the cost with that of providing extra heat input, even if you
> have to use supplementary heating occasionally.
Again, your point is simple and correct. Over time it'll probably be
cheaper to add supplemental heating. But sometimes, if a job's worth
doing, it's worth doing right. The concept of supplimental heating
doesn't give me that fuzzy feeling inside. I'll always feel like I
should have done the job properly.
This discussion is of great interest. But I'm still waiting for
someone to actually reply with "I've done to my house and it was/
wasn't worth the effort" which would prove or disprove if the job's
worth pursuing.
Thanks for everyones replies so far.
Jon
Hot air does.
> Maybe I'd be better off insulating the garage. But the garage door has
> so many gaping holes letting cold air in through the gap between the
> frame that it'd not be cost effective either unless I changed the door
> (expensive).
I'd be inclined to do the garage. OTOH if it's particulary small, you'll
probably not be able to open car doors when you've lost 6" or so off the
walls for insulation. Could you not use foam tape around the door?
(depending on height of rooms)
george
I think I'll start off with some 50mm celotex on the back of the
garage door and insulate any draughts coming through the gaps at the
side this weekend.
Is there any reason why I can't just attach a layer of celotex over
the plastered ceiling in the garage? I know it won't be as pretty as
white plasterboard, but the flame retardent barrier would still be in
tact, albeit covered with celotex. It will also save me a lot of work
removing/replacing plasterboard yet provide a thermal barrier between
the garage and room above.
Is the garage ceiling just plasterboard? Are the garage walls plastered? If
not with all the issues re the garage door, then are you getting a draft
distributed round the edges which funnel under the bedroom skirting around
the edge of the carpet? Are there also gaps around any pipework from the
garage into the ceiling space?
>Are there also gaps around any pipework from the
>garage into the ceiling space?
>
That would be a bit worrying as a fire barrier.
Chris
--
Chris J Dixon Nottingham UK
ch...@cdixon.me.uk
Have dancing shoes, will ceilidh.
The garage ceiling is just plasterboard with no pipework going through
it, the walls are breezeblock. I was thinking of just screwing celotex/
kingspan under the plasterboard ceiling to save on a load of work.
Would that be acceptible and safe?
We had new carpet laid on monday in the room above the garage. Before
it was laid I ripped the old flooring up and sealed under the skirting
with silicone as well as any gaps in the floorboards which were
producing draughts.
Jon
Agreed but I have experienced that in a house (new build) that I purchased
in the late 70s
I cannot answer the issue re acceptability of celotex. Are there gaps
between the walls and the plaster ceiling which would letting cold air get
upstairs?
>
> We had new carpet laid on monday in the room above the garage. Before
> it was laid I ripped the old flooring up and sealed under the skirting
> with silicone as well as any gaps in the floorboards which were
> producing draughts.
Good, that's a help.
You could try giving either your local building control a call, or
Celotex Ltd.
> I looked on the Celotex web
> site, but am not greatly enlightened.
Not good, is it?
I paid a visit to the Kingspan and Cellotex sites earlier today and came
away none-the-wiser so I emailed them. A quick response from Kingspan,
nothing as yet from Celotex.
--
F
(Beware of spam trap - remove the negative)
So what did Kingspan say?