Insulate existing gable wall? BCO

[Tyrone Thompson]

Hi guys/gals

I’ve just had a plans appraisal back from our independent buildings inspector regarding a rear extension and loft conversion. He’s asked my architect to explain how the existing gable end wall will be insulated to ensure a u-value of 0.28W/m2k. Obviously the most practical way of insulating it is for a pumped cavity fill, it was built in 1970 so it is just thermal block, cavity and brick.

have people had experiences with this problem?

 

[dontbelieveawordofit]

don’t let anyone pump wool into your walls. if you have to have something opt for the poly beads.
it’s very coastal where I live and i’ve seen and worked on some wool horror stories.

 

[Johnny Allround]

I would consider your options very carefully. Cavity wall insulation has created more problems than it has solved. There are a number of thermal coating systems that are energy efficient and should get you to the u value he desires. Energy saving trust have a number of products you might want to investigate the one I use is properla. There are so many quality energy saving products out there that won’t jeopardise the integrity of your property. Hope this helps.

 

[Tyrone Thompson]

don’t let anyone pump wool into your walls. if you have to have something opt for the poly beads.
it’s very coastal where I live and i’ve seen and worked on some wool horror stories.

Hi thanks for the advice, is “poly beads” the brand name? If not what is the name and where can I buy this?

 

[Tyrone Thompson]

I would consider your options very carefully. Cavity wall insulation has created more problems than it has solved. There are a number of thermal coating systems that are energy efficient and should get you to the u value he desires. Energy saving trust have a number of products you might want to investigate the one I use is properla. There are so many quality energy saving products out there that won’t jeopardise the integrity of your property. Hope this helps.

Do you know if they supply a data sheet to show how much it does actually improve the u-value?

 

[Johnny Allround]

There products have been tested by EST simply go to properla website for all relevant data. Poly bead is a blown thermal glued ball that sits in the cavity. I will forward some data for you. If they are insisting on a cavity filled product look at isothane or technitherm it’s expensive but will make all the difference.

 

[freddiemercurystwin]

Just stick some insulated plasterboard to the wall inside, no need to faff about with cavity wall insulation. the architect should have shown on it on his drawing.

 

[Tyrone Thompson]

Just stick some insulated plasterboard to the wall inside, no need to faff about with cavity wall insulation. the architect should have shown on it on his drawing.

I reckon the insulated plasterboard required would be quite thick, and would make window reveals ridiculously wide.

 

[Tyrone Thompson]

There products have been tested by EST simply go to properla website for all relevant data. Poly bead is a blown thermal glued ball that sits in the cavity. I will forward some data for you. If they are insisting on a cavity filled product look at isothane or technitherm it’s expensive but will make all the difference.

Forgive me if this sounds like I’m taking advantage of the current coronavirus outbreak, but due to this my brother is on universal credit. This has made us eligible to get the full government grant. I ended up calling propela about their “masonry creme” product, their data sheets don’t show any calculations on u-value but they’re going to get in contact with me about its performance etc, can this literally be painted on with a roller?

 

[Johnny Allround]

Yes you can apply it with brush or rollers. Normally they would use a registered approved contractor. If you have a suspended floor and your boiler is over 6 years old you can have a new one free on Universal Credit.

 

[freddiemercurystwin]

I reckon the insulated plasterboard required would be quite thick, and would make window reveals ridiculously wide.

Well I suppose a whole extra 80mm is absolutely ridiculous. But considerably less ridiculous than insulating all of the cavity walls in the house.

 

[dontbelieveawordofit]

poly beads don’t absorb or transfer moisture through the cavity. It also allows the cavity to breathe.