thin foam polystyrene sheeting behind wallpaper - why?

[JakeD]

I'm redecorating a cottage I recently moved into. When I noticed some
wallpaper peeling, I found that the whole room had been previously papered
with thin polystyrene sheeting, prior to applying the normal (paper)
wallpaper. Why would they have done this? Initially, I wondered if it might
have been to seal in dampness, but there doesn;t seem to be any significant
dampness in the walls, despite being 18" thick solid stone (and 150-yr old
lime mortar). The exterior of the cottage has been well rendered with
modern mortar and painted with Weathershield, so if there IS any damp, I
can't see where it would come from.

Any ideas?

TIA

Jake

[NT]

It was put up for any of the following:
- cover cracks or rough surfaces
- stop damp condensing on walls
- provide a little insualtion


NT

[Tim Watts]

There was a fad for this in the 80's - generally sold on the premise of:

a) Warming the walls to the touch;

b) Smoothing out crap walls;


--
Tim Watts

[Andy Cap]

On 03/11/11 14:59, NT wrote:

> - stop damp condensing on walls

We did our small cold bedroom to stop condensation.
Worked a treat - at least you can wipe it off the windows!

Andy C

[Mike Tomlinson]

In article <0qnao8-...@squidward.local.dionic.net>, Tim Watts
<tw+u...@dionic.net> writes

>There was a fad for this in the 80's

Wouldn't it be dangerous in a fire? (I'm thinking of poly ceiling
tiles).

--
(\__/)
(='.'=)
(")_(")

[stuart noble]

Both of which it actually did rather well. Very vulnerable to knocks though

[NT]

On Nov 3, 2:32 pm, Mike Tomlinson <m...@jasper.org.uk> wrote:
> In article <0qnao8-ir9....@squidward.local.dionic.net>, Tim Watts
> <tw+use...@dionic.net> writes

>
> >There was a fad for this in the 80's
>
> Wouldn't it be dangerous in a fire? (I'm thinking of poly ceiling
> tiles).

yes, and should be removed.


NT

[Man at B&Q]

On Nov 3, 3:15 pm, Tim Watts <tw+use...@dionic.net> wrote:
> JakeD wrote:
> > I'm redecorating a cottage I recently moved into. When I noticed some
> > wallpaper peeling, I found that the whole room had been previously papered
> > with thin polystyrene sheeting, prior to applying the normal (paper)
> > wallpaper. Why would they have done this? Initially, I wondered if it
> > might have been to seal in dampness, but there doesn;t seem to be any
> > significant dampness in the walls, despite being 18" thick solid stone
> > (and 150-yr old lime mortar). The exterior of the cottage has been well
> > rendered with modern mortar and painted with Weathershield, so if there IS
> > any damp, I can't see where it would come from.
>
> > Any ideas?
>
> > TIA
>
> > Jake
>
> There was a fad for this in the 80's

70s

[Nightjar]

We left the house we used it in, to stop condensation on a solid wall,
in 1967.

Colin Bignell

[Ghostrecon]

used n the 60's = my parents put this in my bedroom then went under the
trade name of cttina sp IIRC
--
(º•.¸(¨*•.¸ ¸.•*¨)¸.•º)
<.•°•. Nik .•°•.>
(¸.•º(¸.•¨* *¨•.¸)º•.¸)

[js.b1]

You better remove the vinyl wallpaper, has a superb wicking effect in
hallways... and the 80/20 wool carpets re cyanide... and the PVC
cables... and those unsealed ceiling spots with bare boards above
sometimes lacking T&G in areas re downstairs smoke propogation :-)

Fact is you have 2 mins or so to get out re smoke anyway.

A working smoke alarm up & bottom in the hall is the thing to fit
before taking your shoes off on first walking through the door. Even
two battery units is better than nothing, you can buy Aico Ei 146
Mains Interlinked and run them off their 9V battery for a year or so
whilst you sort out a fused spur off a regularly used lighting circuit
(hall) or dedicated circuit if not too difficult.

[Hugh - Was Invisible]

ISTR it was called Cotina but could be wrong. It is for heat insulation
and quite probably to avoid resultant condensation.

In 1977 I bought a maisonette which the surveyor thought had rising damp
and so the building society wanted a damp proof course installed.

Specialist damp company said it was a leaky downpipe which had recently
been repaired and might be some condensation.

Building society then made it a condition of the mortgage that expanded
polystyrene be used in 2 rooms to avoid condensation. Main problem we
found was that if anything fell against the wallpaper it either dented
or ripped because of the crushable expanded polystyrene underneath.

Turned out that the previous occupiers had blocked the ventilators and
not heated the place adequately.

[charles]

In article
<72c44af3-fd84-4321...@s9g2000yqi.googlegroups.com>,

flameproof polystyrene is available, isn't the "behind wallpaper" stuff
made from it?

--
From KT24

Using a RISC OS computer running v5.16

[Hugh - Was Invisible]

Got the spelling slightly wrong:

http://www.diynot.com/forums/viewtopic.php?t=35178

http://forums.moneysavingexpert.com/showthread.php?t=363779

The other Hugh

[Ghostrecon]

ah not as badly spelled as my effort lol Kotina....

[NT]

A lot of people are pulled out of fires alive and ok after more than 2
minutes.


NT

[js.b1]

On Nov 3, 8:22 pm, NT <meow2...@care2.com> wrote:
> A lot of people are pulled out of fires alive and ok after more than 2
> minutes.

Bit crispy though :-)

[Hugh - Was Invisible]

I used to deal with claims.

Saw a few places where polystyrene tiled kitchen ceilings had
melted/ignited. Very scary.

Only remember 2 fatal domestic fires.

One was an elderly person who apparently fell asleep smoking. The other
was stressed adaptors in a socket beside a bed. Set fire to the bedding.

[Andy Dingley]

On Nov 3, 2:56 pm, JakeD <fgdfg...@ghghfgh.com> wrote:

> I found that the whole room had been previously papered
> with thin polystyrene sheeting, prior to applying the normal (paper)
> wallpaper. Why would they have done this?

The belief that it's equivalent to a foot of real insulation. In
practice it has very little insulation value, simply from being too
thin.

It does have some use for reducing condensation on cold walls. It
doesn't reduce the heat flowing by much, but it does raise the
temperature of the inside face of the wall to above the dewpoint.

[geraldthehamster]

> 70s- Hide quoted text -
>
> - Show quoted text -

I remember hanging this when decorating bedrooms, around 1984.

Cheers
Richard

[Hugh - Was Invisible]

When I hung it in 1977 It was a bit fragile and bends and corners were
tricky because expanded polystyrene even when relatively thin is not
exactly flexible beyond the curvature of the rolls it was bought in.

[stuart noble]

And yet 5mm of foam on the wall can halve heat loss through brick? Not
my figures, but my experience suggests that a little insulation makes a
big difference

[Hugh - Was Invisible]

When we had it the coated walls always felt warm to the touch because
heat was not conducted away from our hands.

[Brian Gaff]

Yes its in my house as well, seems to have survived quite well actually. I
think the issue was use of a parafin heater.

Brian

--
Brian Gaff - bri...@blueyonder.co.uk
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"NT" <meow...@care2.com> wrote in message
news:e2cc426d-c7be-4471...@q13g2000vbd.googlegroups.com...

[Brian Gaff]

Yes, this house does not have cavity walls and with the paraffin heater it
stopped condensation on the walls dead in its tracks.

Brian

--
Brian Gaff - bri...@blueyonder.co.uk
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!

"Hugh - Was Invisible" <invi...@invalid.invalid> wrote in message
news:j90b6t$fp8$1...@dont-email.me...

[JakeD]

Thanks to all for the informative input! Having read all the suggested
pros and cons of the said foam sheeting, I'm inclined to scrape it all
off, and paint the bare walls with regular emilsion.

It's very true that it makes the walls seem warm to the touch, but I
can't really see how 1/8" of anything is going to make any significant
difference to the overall thermal insulation of an 18" thick solid stone
wall. I could be wrong.

As for the condensation issue, the heating in this house is now coming
from radiant/convecting gas fires which I've recently installed. Their
moisture-ridden exhaust goes up the chimney, but I wonder if I will still
suffer condensation problems if I remove the polystyrene foam sheet from
the walls...

As someone rightly said, one of the main problems with the stuff is that
a bump or knock to the wall easily creates a nasty scar that's difficult
to repair.

Another disadvantage, is that it makes it impossible to remove the
wallpaper without damaging the foam. So the previous owners of this house
have simply painted over the paper numerous times. This seals in any
slight moisture, causing moild to grow underneath.

My guess is that it's probably better to remove the foam and just paint
the walls with emulsion.

I was going to say that the stuff must have been largely a con, otherwise
it would be more widley in use today. However, perhaps the reason it is
not so widely used today, is that almost no-one uses parrafin heaters any
more!

Apart from being an anti-condensation measure, I suspect the foam in my
house was added to even out what looks like some rather rough plastering.
What is the easiest/cheapest way to smooth over iregularities and
roughness in plaster? Polyfilla, applied a wide spatula/spreader perhaps?
I don't want to go to the trouble and expense of applying plasterboard to
the walls. And I don't want to use embossed (or similar) wallpaper. I
could skim-coat with plaster, except that the underlying walls have been
painted with what looks like vinyl silk or similar.


TIA

Jake

[damdu...@yahoo.co.uk]

On Thu, 03 Nov 2011 15:15:44 +0000, Tim Watts <tw+u...@dionic.net>
wrote:

>JakeD wrote:
>
>> I'm redecorating a cottage I recently moved into. When I noticed some
>> wallpaper peeling, I found that the whole room had been previously papered
>> with thin polystyrene sheeting, prior to applying the normal (paper)
>> wallpaper.

>> Jake
>
>There was a fad for this in the 80's - generally sold on the premise of:
>

I would have thought it was 20 years earlier than that,parents did
some bedrooms around 1964.

>a) Warming the walls to the touch;

Remember actually touching the stuff and getting that effect. Hard to
believe now but it was seen as a new wonder material at the time.

>
>b) Smoothing out crap walls;

Our walls were reasonably smooth .Stone built with no cavity but
rendered quite well.

G.Harman

[John Rumm]

On 03/11/2011 14:56, JakeD wrote:
> I'm redecorating a cottage I recently moved into. When I noticed some
> wallpaper peeling, I found that the whole room had been previously papered
> with thin polystyrene sheeting, prior to applying the normal (paper)

> wallpaper. Why would they have done this? Initially, I wondered if it might
> have been to seal in dampness, but there doesn;t seem to be any significant
> dampness in the walls, despite being 18" thick solid stone (and 150-yr old
> lime mortar). The exterior of the cottage has been well rendered with
> modern mortar and painted with Weathershield, so if there IS any damp, I
> can't see where it would come from.
>
> Any ideas?

It was sold to provide a small amount of insulation and make the wall
"feel" warmer to the touch. Quite effective at reducing condensation
forming on the walls.


--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

[Ghostrecon]

On 4 Nov 2011 11:41:22 GMT, JakeD wrote:

> Thanks to all for the informative input! Having read all the suggested
> pros and cons of the said foam sheeting, I'm inclined to scrape it all
> off, and paint the bare walls with regular emilsion.
>
> It's very true that it makes the walls seem warm to the touch, but I
> can't really see how 1/8" of anything is going to make any significant
> difference to the overall thermal insulation of an 18" thick solid stone
> wall. I could be wrong.
>
>

as a rough estimate treating the 450mm stone wall as dense brick you woud
have R as 0.34 (U of 2.9) by itself .... with 5mm of expanded polystyrene
r= 0.5 (U u of about 2) .. so would reduce heat loss to about 67%
surprisingly effective for such a small addition... but I could be wrong
:-)

[stuart noble]

This would appear to make the 22 mm Gyproc Thermaline (12mm of
insulation) an attractive proposition for 9" walls. It's the hacking off
I can't face.

[Ghostrecon]

using he same figures for the thermal conductivity of the brick wall + 10mm
of plaster that gives r =0.19 (u of 5.2) compared to wall+plasterbord
+thermaline r= 0.59 (u of 1.69)so a eduction of heat loss to 33% ish

[stuart noble]

Thanks for doing the sums :-)
The way fuel bills are going, the payback time for replastering might
make it a sensible plan.

[JakeD]

Ghostrecon <m...@privacy.net> wrote in
news:995qqn8xxr3y.11pt69rt0lfnx$.d...@40tude.net:

>> Thanks to all for the informative input! Having read all the
>> suggested pros and cons of the said foam sheeting, I'm inclined to
>> scrape it all off, and paint the bare walls with regular emilsion.
>>
>> It's very true that it makes the walls seem warm to the touch, but I
>> can't really see how 1/8" of anything is going to make any
>> significant difference to the overall thermal insulation of an 18"
>> thick solid stone wall. I could be wrong.
>>
>>
>
> as a rough estimate treating the 450mm stone wall as dense brick you
> woud have R as 0.34 (U of 2.9) by itself .... with 5mm of expanded
> polystyrene r= 0.5 (U u of about 2) .. so would reduce heat loss to
> about 67% surprisingly effective for such a small addition... but I
> could be wrong

That's surprising. One still has to consider the disadvantages of the
stuff: scuffability, falammabilty etc. It would cost me about £20 to cover
the two stone walls in the room (9140mm x 600mm costs £4 at B&Q). I'm
thinking that the cost would be better spent on adding loft insulation. The
loft above the room only has about 6" of rockwool. I can buy rockwool at £3
for 200mm x 3200 x 1140mm at the moment. Therefore it would cost me £9 to
add an extra 6" of loft insulation above the room.

What do you think?

Jake

[dennis@home]

"JakeD" <fgdf...@ghghfgh.com> wrote in message
news:Xns9F93B7CEC8...@130.133.4.11...


> What do you think?

Don't overestimate the effects of insulation.
Putting 6" of Rockwool on a ceiling will reduce the heat loss by a lot.
Adding another 6" will only halve the bit of heat that is escaping.

You need to do the sums to see which will save the most and what payback
period you will get.
In most houses there is a lot more wall so loses tend to be higher through
the walls.

[Ghostrecon]

with just a plasterboard ceiling you have a u of 15 ish (r=0.065) adding
150mm of rockwool will reduce it to a u of 0.22 (r=.4.3) adding another
150mm will reduce your u to 0.11 (r=8.4)so you geta big change adding the
first insulation (15->0.22) but only a small change when you add the next
150mm (0.22->0.11) so pyback time is longer - dramatically

[Ericp]

On Fri, 04 Nov 2011 12:06:35 +0000, John Rumm
<see.my.s...@nowhere.null> wrote:

>On 03/11/2011 14:56, JakeD wrote:
>> I'm redecorating a cottage I recently moved into. When I noticed some
>> wallpaper peeling, I found that the whole room had been previously papered
>> with thin polystyrene sheeting, prior to applying the normal (paper)
>> wallpaper. Why would they have done this? Initially, I wondered if it might
>> have been to seal in dampness, but there doesn;t seem to be any significant
>> dampness in the walls, despite being 18" thick solid stone (and 150-yr old
>> lime mortar). The exterior of the cottage has been well rendered with
>> modern mortar and painted with Weathershield, so if there IS any damp, I
>> can't see where it would come from.
>>
>> Any ideas?
>
>It was sold to provide a small amount of insulation and make the wall
>"feel" warmer to the touch. Quite effective at reducing condensation
>forming on the walls.

Bought some rolls from Wickes last month for condensation problem.
Lovely stuff. :)

[Pete Shew]

Would that be Erfurt Wallrock? We have just put some up on a 9" solid
brick exterior wall to combat condensation. Not cheap and nor is the
(PVA based?) adhesive, but it goes on very easily and with a finish
that's ready to paint.

Time will tell whether it works.

Pete

[JakeD]

Hugh - Was Invisible <invi...@invalid.invalid> wrote in

news:j908q0$340$1...@dont-email.me:

>>>> JakeD wrote:
>>>>> I'm redecorating a cottage I recently moved into. When I noticed
>>>>> some wallpaper peeling, I found that the whole room had been
>>>>> previously papered with thin polystyrene sheeting, prior to
>>>>> applying the normal (paper) wallpaper. Why would they have done
>>>>> this? Initially, I wondered if it might have been to seal in
>>>>> dampness, but there doesn;t seem to be any significant dampness in
>>>>> the walls, despite being 18" thick solid stone (and 150-yr old
>>>>> lime mortar). The exterior of the cottage has been well rendered
>>>>> with modern mortar and painted with Weathershield, so if there IS
>>>>> any damp, I can't see where it would come from.
>>>
>>>>> Any ideas?
>>>
>>>>> TIA
>>>
>>>>> Jake
>>>
>>>> There was a fad for this in the 80's
>>>
>>> 70s- Hide quoted text -
>>>
>>> - Show quoted text -
>>
>> I remember hanging this when decorating bedrooms, around 1984.
>>
>> Cheers
>> Richard
>>
> When I hung it in 1977 It was a bit fragile and bends and corners were
> tricky because expanded polystyrene even when relatively thin is not
>

The other thing I don't like about it is that wallpaper doesn't seem to
stick very well to it. The wallpaper is lifting off the polystyrene
sheeting in my house, especially around windows. That was what made me
inclined to scrape it all off and just paint with emulsion. Having said
that, if I do so and find I start getting condensation during Winter, I
will probably re-do with new polystyrene sheet or some alternative anti-
condensation material.

Jake

[stuart noble]

Sounds like a big improvement over polystyrene from a practical point of
view

[Pete Shew]

It is certainly much more structurally durable. SWMBO stepped back and
put her heel on the edge of a piece lying on the floor with no
noticeable effect. It has a hardish smooth side and a fluffy side. Gob
glue on the wall with a roller and stick it on. Butt the edges to leave
a smooth finish, but any gaps can be filled with caulk or even the glue
which has a filler in it so it will go over rough walls.

No association with the company, but surprised how easy it was to put up
(and I've hung a lot of rolls of paper in my life).

Pete

[Dave Liquorice]

On Fri, 04 Nov 2011 16:37:28 +0000, stuart noble wrote:

> The way fuel bills are going, the payback time for replastering might
> make it a sensible plan.

I think it would. Solid walls conduct heat out of room very quickly.
Bunging a 25mm foam + 12.5mm plasterboard lining(*) in will make a
very significant difference to the energy consumption far more than
adding 6" of wool on top of an existing 6". Think of the relative
areas I suspect you have far more external wall area than you do
ceiling.

That few mm of polystrene will be making a difference as well. So if
you do remove it expect the rooms to feel colder, might not see much
change in energy consumption but comfort is another matter. The walls
will be colder and air flow patterns different.

Dot and dab or onto 2x1 battens.

--
Cheers
Dave.

[stuart noble]

I think the Gyproc Thermaline (12mm + 9.5mm) might be more practical,
given that it would replace the existing plaster, and skirtings and door
frames wouldn't need to be adjusted.

[Dave Liquorice]

On Tue, 08 Nov 2011 11:53:23 +0000, stuart noble wrote:

> I think the Gyproc Thermaline (12mm + 9.5mm) might be more practical,

That is still thicker than plaster + skim by 6mm ish... and doesn't
take into account dot 'n dab or battening...

> given that it would replace the existing plaster, and skirtings and door
> frames wouldn't need to be adjusted.

Hacking the old plaster off would be *very* messy and disruptive.
Believe me, that has happened here due to the old stuff being poor
quality, occasionally damp and not particulary even. We aren't trying
to live in the bit that is being worked on but even with three doors
and two rooms between the bit we are and the work the dust is still
getting through. Not much but definately there. Hacking the plaster
off would also mean removing skirtings and architraves as it goes
behind both.

--
Cheers
Dave.

[Alan Braggins]

In article <nyyfbegfubjuvyypb...@srv1.howhill.co.uk>, Dave Liquorice wrote:
>On Fri, 04 Nov 2011 16:37:28 +0000, stuart noble wrote:
>
>> The way fuel bills are going, the payback time for replastering might
>> make it a sensible plan.
>
>I think it would. Solid walls conduct heat out of room very quickly.
>Bunging a 25mm foam + 12.5mm plasterboard lining(*) in will make a
>very significant difference to the energy consumption far more than
>adding 6" of wool on top of an existing 6". Think of the relative
>areas I suspect you have far more external wall area than you do
>ceiling.

[...]

>Dot and dab or onto 2x1 battens.

Many years ago my father did that to a north-facing solid brick wall
(simplified by not havng any windows in it). Made a huge difference
to the comfort of the rooms.

(I'm considering doing something similar to timber framed walls that
do have insulation in, but the proportional benefit will be less and
there are windows. The skeilings where increasing insulation means
either doing it in the room or (probably) taking the tiles off the
roof to replace fibreglass with Kingspan/Celotex/whatever because
the glass is already the full depth of the rafters are a higher
priority though.

Unless anyone has suggestions on how to get a long length of board down
between the rafters from the loft while keeping it tightly fitting?

Googling for a polystyrene "concertina" board I'd seen shows up Xtratherm
Rafterloc as a similar "squeezable" construction in polyisocyanurate,
but it is worth paying the price of the better material if you then cut
lots of (thin) grooves most of the way though it?
http://www.xtratherm.com/products/thinrrafterloc.php )

[m...@privacy.net]

On 8 Nov,

"Dave Liquorice" <allsortsn...@howhill.co.uk> wrote:

> Hacking the old plaster off would be *very* messy and disruptive.

Our kitchen (when we moved in) didn't have space for a cooker and was tiled
throughout with two types of obselete dark brown tiles. When we extended ten
years later I hired a kango hammer and with great delight removed the last of
the awful tiles, complet with teh plaster.

> Believe me, that has happened here due to the old stuff being poor quality,
> occasionally damp and not particulary even. We aren't trying to live in the
> bit that is being worked on but even with three doors and two rooms between
> the bit we are and the work the dust is still getting through. Not much but
> definately there. Hacking the plaster off would also mean removing
> skirtings and architraves as it goes behind both.
>

I don;'t remeber much getting out of the kitchen, but we had just had three
weeks ob builders at it extending so the extra dust didn't show.

Re-fitting the skirting/architrave after dot and dabbing (no extra insulation
then -- 20 years ago) was a minor inconvenience[1].

[1] Half the skirtings are now removed following a flood and floor removal
allowing the intallation of insulation under the timber floor. The half done
so far seems to have made a noticable difference in the comfort level.

--
B Thumbs
Change lycos to yahoo to reply

[Andy Dingley]

On Nov 4, 9:06 am, stuart noble <stuart_no...@ntlworld.com> wrote:
> And yet 5mm of foam on the wall can halve heat loss through brick?

{{cn}}

Post the U values, then we dont need to guess.

[John Rumm]

Indeed, it does not sound that plausible...

The k value for EPS is about 0.035 W/mK, so 5mm of it would yield a U
value of 7

9" solid brick wall has a U value of about 2.2. So together you get a
reduction to 1/(1/2.2 + 1/7) = 1.7

[stuart noble]

On 12/11/2011 03:29, John Rumm wrote:
> On 11/11/2011 22:45, Andy Dingley wrote:
>> On Nov 4, 9:06 am, stuart noble<stuart_no...@ntlworld.com> wrote:
>>> And yet 5mm of foam on the wall can halve heat loss through brick?
>>
>> {{cn}}
>>
>> Post the U values, then we dont need to guess.
>
> Indeed, it does not sound that plausible...
>
> The k value for EPS is about 0.035 W/mK, so 5mm of it would yield a U
> value of 7
>
> 9" solid brick wall has a U value of about 2.2. So together you get a
> reduction to 1/(1/2.2 + 1/7) = 1.7
>
>
>

NP's figures IIRC