Installing sliding patio doors - what goes in the cavity?

[richie9648]

Hi

 

Im having some sliding doors fitted in a few months and the door installers have insisted that I insulate the cavity (which I get) and install compac foam cavity closer (on the base and sides) so that the door can be fixed securely and also for thermal bridging.  
 

it was a bit of a last moment decision to with these guys and the builder has poured concrete in the base cavity but the door people are insisting on the compac foam to be installed

 

can they not just fix to the concrete that has gone in? Is the compac foam a normal thing as I’ve never heard of it!!

 

thanks 

 

 

[Mr Punter]

I have heard of it but never seen it in merchants or on site.  I think it is a specialist product.

[richie9648]

4 hours ago, Mr Punter said:

I have heard of it but never seen it in merchants or on site.  I think it is a specialist product.

Thanks - what’s the ‘normal’ way to deal with the cavity when installing patio doors? 

[Mr Punter]

If it is brick and block the doors often sit mostly on the outer leaf.  I don't have the inner leaf built at thresholds - just 25mm perimeter insulation and have the floor slab and screed run up to that, so there is only a 25mm cavity at that point.

[Iceverge]

Compacfoam would help thermal bridging. It depends on how good/bad your house is at the moment if it's worth it. 

 

Have you comitted to a sliding door? Does it have compression or brush seals? The latter are really drafty. Switch to lift+slide or tilt+slide or french doors if there's still time.