Window positioning in the solid wall with external insulation

[romario]

It would be great to see what are other people thoughts are on the best position to place the windows in the solid 215 block wall with external 150mm PIR insulation and timber cladding.

Thermally and visually I am thinking to place them just outside of the block work (within the PIR insulation) that should eliminate any thermal bridging and have good 215mm internal window sill.

However, will the windows be well secured just on some straps and sitting within the PIR insulation?

 

 

 

 

[Conor]

Interested, as that's what I'm planning with my ICF build - window frame sitting on the external EPS and secured to the concrete core with straps. Same as you, concerned that windows would sag if not having at least a partial edge on the concrete.

[oranjeboom]

Depends on the weight of the windows. Some of mine weighed over 200kg so standard window straps will likely fail! There are bespoke EWI window supports that you can get (I got mine from Fischer) but they'll be beyond your average double-glazing window fitter to work out (I ended up having to fit most of my windows as they were clueless).

 

A bad pic, but you can just make out the brackets:

 

This was cavity wall, but the brackets are better suited to solid wall as you have more fixing points.

 

There is also the option of timber supports:

 

 

But that also introduces a cold bridge.

 

There's also another product like foamglass (indeed it may be foamglass) that will support the windows. I think someone on here may have used it...

 

 

[Adam2]

Really interesting am just thinking of the same challenge for mine, also ICF. Are you planning to render over the edge of the window frame and have no cills (though I see one pic has a cill)??

[oranjeboom]

9 minutes ago, Adam2 said:

Really interesting am just thinking of the same challenge for mine, also ICF. Are you planning to render over the edge of the window frame and have no cills (though I see one pic has a cill)??

 

First pic is mine, the timber approach pic is from the net.

 

Edge of windows will be 'covered' with insulation (100mm EPS) and this will be rendered.

 

The alu cills fit onto a bottom 'rail' that you can just make out (see grey):

 

Above pic is for my SIPs extension, but the windows have the same cill profile underneath.

[Mr Punter]

I would go for 30mm inside the blockwork, fixed with straps. Gives them something solid to sit on and pack out from.  We have some IdealCombi windows and they are about 130mm deep, so the glazing should be well within the insulation.

 

@romario how are you fixing your battens for the timber cladding?  150mm plus batten thickness is a sizeable fixing.

[romario]

1 hour ago, oranjeboom said:

Depends on the weight of the windows. Some of mine weighed over 200kg so standard window straps will likely fail! There are bespoke EWI window supports that you can get (I got mine from Fischer) but they'll be beyond your average double-glazing window fitter to work out (I ended up having to fit most of my windows as they were clueless).

 

A bad pic, but you can just make out the brackets:

 

This was cavity wall, but the brackets are better suited to solid wall as you have more fixing points.

 

There is also the option of timber supports:

 

 

But that also introduces a cold bridge.

 

There's also another product like foamglass (indeed it may be foamglass) that will support the windows. I think someone on here may have used it...

 

 

Thank you for sharing

[romario]

49 minutes ago, Mr Punter said:

I would go for 30mm inside the blockwork, fixed with straps. Gives them something solid to sit on and pack out from.  We have some IdealCombi windows and they are about 130mm deep, so the glazing should be well within the insulation.

 

@romario how are you fixing your battens for the timber cladding?  150mm plus batten thickness is a sizeable fixing.

Thank you for your comments Mr Punter.

 

In terms of fixing the cladding is even more interesting as it is a round house

I haven't decided yet but I am considering couple different options.

One of them is to lay some battens on top of the insulation let's say 25 -38mm thick

This will make the wall unnecessarily thicker but then having a bit of air gap between cladding and insulation maybe would be a good think....

 

I've attached architect vision image below.

 

[Mr Punter]

I think tiling the roof will be more of a challenge!

 

If you are doing vertical cladding as shown you will need vertical battens fixed to the timber frame, then horizontal battens fixed to the vertical.  I did some 25mm x 50mm horizontal battens on a radius of 3800mm. I soaked the battens and pre-bent them.  They were for render board finish.

 

[romario]

1 hour ago, Mr Punter said:

I think tiling the roof will be more of a challenge!

 

If you are doing vertical cladding as shown you will need vertical battens fixed to the timber frame, then horizontal battens fixed to the vertical.  I did some 25mm x 50mm horizontal battens on a radius of 3800mm. I soaked the battens and pre-bent them.  They were for render board finish.

 

Thank you for sharing.

I have 10m radius so should be able to bend the battens.

Tiling roof will be interesting

 

[craig]

This may be of interest to you.

 

 

If your sitting within the opening of ICF, details are floating about here somewhere. I’ll link to them if I can find them.

Edited June 27, 2019 by craig

[romario]

3 hours ago, craig said:

This may be of interest to you.

 

 

If your sitting within the opening of ICF, details are floating about here somewhere. I’ll link to them if I can find them.

Thank you,

That looks interesting