Pumped insulation and porus stone

jay0109

Hi

I'm in the process of getting EWI on the 2 sides and back of my house as there is no cavity in the walls so pumping was out. But the front has a cavity and we thought we could pump in beads there but the company doing this are now saying it won't be possible.
The front of the house has a decorative stone facade, then a cavity and then the internal block work. They are saying if they pump the bead into the cavity, they cannot guarantee it as they believe the stone facade is porus. And the bead manufacturers won't guarantee their own product in a situation like this.

They are prepared to entertain other bead or foam type insulation if it comes guaranteed for use in this type of wall. My question for the Experts on here - has anyone any names of products or companies they know of which may have a product that could be used here?

thanks

Calahonda52

I don't think anyone will provide the assurances you need

jay0109

It's not really assurances I'm after. More like anyone's experience of a similar situation where they found a product that worked

Lumen

I'd be a bit nervous of it blowing the facade off, but...

https://walltite.basf.ie/news/2015/09/15/soon-to-be-featured-on-channel-4s-restoration-man

"The external walls posed a particular challenge. A yorkshire stone facade is lined with brick and lime mortar - an inherently porous structure. WALLTITE® is resistant to moisture but the project architect, wanting complete assurance of water resistance, asked for a drainage mat to be fixed to the wall prior to application of WALLTITE®. Plasterboard was then used as an internal finish and base for the interior decoration."

jay0109

Thanks Lumen

Calahonda52

Lumen wrote: »

I'd be a bit nervous of it blowing the facade off, but...

https://walltite.basf.ie/news/2015/09/15/soon-to-be-featured-on-channel-4s-restoration-man

"The external walls posed a particular challenge. A yorkshire stone facade is lined with brick and lime mortar - an inherently porous structure. WALLTITE® is resistant to moisture but the project architect, wanting complete assurance of water resistance, asked for a drainage mat to be fixed to the wall prior to application of WALLTITE®. Plasterboard was then used as an internal finish and base for the interior decoration."

Its not clear where the stuff was applied but for me it's the wrong answer because he already had a nice moisture/moisture vapour porous construction and now he has fitted what sounds like an impermeable layer of *tite and compounded the problem with the pb/skim as the inside face.

dathi

Lumen wrote: »

I'd be a bit nervous of it blowing the facade off, but...

https://walltite.basf.ie/news/2015/09/15/soon-to-be-featured-on-channel-4s-restoration-man

"The external walls posed a particular challenge. A yorkshire stone facade is lined with brick and lime mortar - an inherently porous structure. WALLTITE® is resistant to moisture but the project architect, wanting complete assurance of water resistance, asked for a drainage mat to be fixed to the wall prior to application of WALLTITE®. Plasterboard was then used as an internal finish and base for the interior decoration."

they tanked the walls internally with polyethylene dimpled drainage mat, that left a gap between wall and mat then sprayed the foam onto the mat and finished with plasterboard . the gap between wall and mat is used as a drainage channel