Wall insulation

wiskyjack

We need to insulate out house as it was built in the early 70 and has no cavity, solid blocks plastered inside and out. We are strongly leaning towards external insulation.

Can anyone tell me, can you build onto external insulation ie porch sunroom extention. Also can windows and doors be changed after the insulation is applied.

Outkast_IRE

wiskyjack wrote: »

We need to insulate out house as it was built in the early 70 and has no cavity, solid blocks plastered inside and out. We are strongly leaning towards external insulation.

Can anyone tell me, can you build onto external insulation ie porch sunroof extention. Also can windows and doors be changed after the insulation is applied.

It would be highly recommended to do any changes to windows or doors before you insulate externally. Although the same could be said for internal insulation or cavity insulation, it will ensure that you can be left with the neatest possible finish for years to come.

If you were building on in the future they would cut back the external insulation to the solid wall so your new structure meets the old structure, there is no other reasonable way to do it. Its not that big a deal it just needs someone who is patient and careful doing the work. You would then externally insulate the new section to minimise cold bridging.

Calahonda52

I agree with the above, with a slight wrinkle:)

In some Passive house designs I have seen, the porch is not actually fixed to the main house where external wall insulation EWI is involved.
This makes it easier all round and the porch is not part of the treated floor area etc etc.
I have a picture somewhere, will go look for it.

As for the new windows, if going EWI then the new windows can be hung on the outside of the wall.
This option allows the EWI to be full depth right up to the window, in a typical retro EWI with existing windows the insulation on the existing reveal can be down to 6 mm

As for the sunroof ext, you could make provision for it before the EWI

Outkast_IRE

Calahonda52 wrote: »

In some Passive house designs I have seen, the porch is not actually fixed to the main house where external wall insulation EWI is involved.

That sounds pretty interesting, just out of interest how it the gap between the "free standing porch" and the main building bridged.

wiskyjack

Calahonda52 wrote: »

I agree with the above, with a slight wrinkle:)

In some Passive house designs I have seen, the porch is not actually fixed to the main house where external wall insulation EWI is involved.
This makes it easier all round and the porch is not part of the treated floor area etc etc.
I have a picture somewhere, will go look for it.

As for the new windows, if going EWI then the new windows can be hung on the outside of the wall.
This option allows the EWI to be full depth right up to the window, in a typical retro EWI with existing windows the insulation on the existing reveal can be down to 6 mm

As for the sunroof ext, you could make provision for it before the EWI

Thank you for the reply. The reason I ask about the new Windows is it have seen videos showing a thin strip of EWI fixed into the reveal from the window frame to the lead edge to stop water ingress ect ect. If I understand you are new window can be fitted onto this??????

Calahonda52

wiskyjack wrote: »

Thank you for the reply. The reason I ask about the new Windows is it have seen videos showing a thin strip of EWI fixed into the reveal from the window frame to the lead edge to stop water ingress ect ect. If I understand you are new window can be fitted onto this??????

No.
Cant find the pics so see post 1170 here http://www.boards.ie/vbulletin/showthread.php?t=2055036901&page=78
See the way the windows are hung in the first pic