How to insulate 30s semi bay window

[Djomidlands]

Hello, I’m decorating the master bedroom of the 30s semi. The bay window is currently not insulated. It looks to have the original plaster on laffs and nothing behind. Externally, I don’t believe there to be a brick wall. The house is pebbledashed from the front. How’s best to insultate?

Should I remove the plaster and laffs and insulate behind with Kingspan or celetex or build a timber frame in front of the existing plasterboard and insulate behind that?

 

[Swwils]

Consider EWI and a ventilation strategy

 

[noseall]

Hello, I’m decorating the master bedroom of the 30s semi. The bay window is currently not insulated. It looks to have the original plaster on laffs and nothing behind. Externally, I don’t believe there to be a brick wall. The house is pebbledashed from the front. How’s best to insultate?

Should I remove the plaster and laffs and insulate behind with Kingspan or celetex or build a timber frame in front of the existing plasterboard and insulate behind that?

20160107_085741 (3)

• noseall
• 24 Apr 2016

Bow2

• noseall
• 24 Apr 2016

Bow3

• noseall
• 24 Apr 2016

Bow5

• noseall
• 24 Apr 2016

Bow4

• noseall
• 24 Apr 2016

Bow6

• noseall
• 24 Apr 2016

As long as there is decent overhang on the existing window board, you should strive to fit the thickest possible layer of PIR insulation (+ foil tape) across the studs, as well as between. I think I managed 75mm between and 50mm across.

 

[Djomidlands]

20160107_085741 (3)

• noseall
• 24 Apr 2016

Bow2

• noseall
• 24 Apr 2016

Bow3

• noseall
• 24 Apr 2016

Bow5

• noseall
• 24 Apr 2016

Bow4

• noseall
• 24 Apr 2016

Bow6

• noseall
• 24 Apr 2016

As long as there is decent overhang on the existing window board, you should strive to fit the thickest possible layer of PIR insulation (+ foil tape) across the studs, as well as between. I think I managed 75mm between and 50mm across.

thanks for the response. Did you leave an air gap?

 

[noseall]

thanks for the response. Did you leave an air gap?

No. Filled the space with insulation. It was however, quite draughty on the cold side.

 

[IJWS15]

Don’t forget to insulate under the floor and the bit above the window downstairs.

 

[Djomidlands]

Thanks. For the avoidance of doubt- what is reasoning?

Will there be an issue if I’m unable to?