Cavity wall insulation

Cernunnos

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Surely there must be some sort of insulating wallcovering option for those without cavity wall insulation for an eqivelent price. Especially if some of us could do with the house being re-rendered, is there nothing for Those of us with 1900 terraces that have solid walls.

There is.
I've spent the last 3 years and probably the next 2 installing it on high rise tower blocks in Glasgow. :eek:


And...? So what's the product & how do I get it or an equivelent & what if any is the equivelent...?

The product we're installing across the city is called Permarock. There are numerous other insulated external render systems available some of which may be more suited to application on low rise domestic properties.
There are a few drawbacks to using these sytems though - They effectively increase the wall thickness which means that alterations may be required to the roofline and any rainwater goods. Any vents or other service penetrations through the wall need to be extended to accommodate the additional thickness of the insulation. Same goes for windowcills. The biggest drawback I can see for installation of this type of system to a house is that they are susceptible to mechanical damage. The systems generally comprise a thin coat acrylic render over a thick layer of insulation an this thin shell of render breaks when kids crash bikes in to it or kick a football against it. They can be reinforced however.

Also..... they can be very expensive. Upwards of £100 per square metre would not be unreasonable.

The upside? They will make your house extremely toasty and warm.

Many thanks. Will look around the net, in preperation for the time I can actually afford to get this sort of thing done. Never hurts to be prepared.
 

viscount17

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my partner recently investigated getting cavity wall insulation and the loft insulation done. The loft worked out fine, except you now can't put anything in the loft as the insulation is so deep.
Problem was we found out she doesn't have cavity walls. It's post-war (late 50's or 60's I think) with timber cladding. No-one mentioned if there was an alternative that she could get.

The govt scheme doesn't cover this sort of construction. If you need to insulate the timber frame the best way to remove the plaster board, and fill the stud wall with something like celotex. Damn good stuff, but not cheap, and unfortunately not subsidised either - I was fortunate in as much as I had a water leak insurance claim a few years ago which gave me the chance to clad my daughters bedroom with this stuff ( her room is an extension btw ) and it is now the warmest room in the house.

But that one room cost about 3 times as much as the rest of the house put together.

poor description on my part.

the walls are concrete skimmed breeze block with an outer cladding of timber (poor quality timber at that). I think they were a cheapo build as they also have tin roofs and some poor quality bricks.
 

CrapHacker

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So living in a barn conversion with a half brick and half ship-lapped board construction how would this work. During the winter we are getting a hell of a draft through all of the walls. After taking one of the boards off we have found there to be celotex wedged in between the joists and what looks like roof felt as a liner!! Obviously air can find its way through any little gaps and I feel that celotex was not the best insulator. Could you use caity wall insulation in this situation?

Unlikely tbh :(

The Celotex is there to stop heat transfer, not drafts. This isn't my line of expertise, tho'. I'd suggest having a word with an expert, even if it involves a small consultation fee.

Soz
 

Ken_A

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Some insulation is a bye product of my business- Modern Method of Design Engineer, I design SIP's, Timber Frame, Metal frame and closed panel systems.

With new regs Insulation seems to be my main research, whereas 4 years ago it was only dodgy design and bad building practice I had to worry about.

Regarding the draughty celotex these PIR boards are FANTASTIC if a bit too expensive, I love the Celotex brand but they are hard (possibly impossible IMHO) to install, I always recomend that the bulder bus a few tins of expanding foam and runs a line down the side of the rigid board to timber inetsection removing any air leckage and enegry loss through these areas.

Regarding the retrofit cavity wall insulation - do it if required, it is the 2nd best saving on your fuel bills - first geing the roof insulation. It is acceptable to full fill the cavity with 'blown balls' as a retrofit, however our building regs in NI still state new bui;ds need min of 40mm cavity if usingh cavity construction strange as it was only designed as a moisture break for driven rain (as mentioned by someone)

If you have no cavity you have a few choices - but only if your pockets are DEEP - an external system as noted by CM_QS above or insulated plasterboard - basically the same idea but for use inside - remove all the internal palster on the external walls and replace with this £30 a sheet its not cheap tho, posible problems with stairs, windows doors etc.
Next is a YBS airtec type insulation - http://www.ybsinsulation.com/products_wall_airtec-drylining.htm
Expensive but should give less problems than the insulated board. Dont like the lack of thermal density on these materials ~ I am in a jury's out type of thought but I would really love to have a good look at the science behind them.
Millions of options I would be happy to give my tuppence worth if you have any q's I can help with - I am not an expert but I may beable to help.
 

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Regarding the retrofit cavity wall insulation - do it if required, it is the 2nd best saving on your fuel bills - first geing the roof insulation. It is acceptable to full fill the cavity with 'blown balls' as a retrofit,

Good post.

A couple of minor points I'd like to comment on tho'.

According to the Energy Savings Trust, I believe that heat loss through cavity walls is about 35% of heat loss, and through the loft is about 25-30%. So they're pretty much as important as each other. Although it seems from just a straw poll on customers ( no science attached ) that CWI gives a more immediate improvement in feel around the house. It seems to have a higher cosyabilty factor.

You mention blown balls. ( Must resist cheap gag, must resist....) But the best product on the market at the moment is Knauf Supafil, a mineral wool.
 
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