Roof eaves/outer wall detail

[4square]

On my 1960's house, the eaves soffit boards are level with top of first floor windows - fairly common, I think. However, I get the impression from looking from inside the loft that while the concrete lintel over the top of the window frame supports the inner layer of brickwork, there is no outer layer of brick/blockwork - there doesnt look room for it under slope of roof. This means, that inside the first floor rooms, the brickwork over the windows - about 300mm high - is only one layer thick, which is probably why it seems to create cold surfaces of condensation, etc. Am I right in this conclusion, and is there any way to help insulate the area over the windows? Advice much appreciated.

[Dave Fawthrop]

| On my 1960's house, the eaves soffit boards are level with top of | first floor windows - fairly common, I think. However, I get the | impression from looking from inside the loft that while the concrete | lintel over the top of the window frame supports the inner layer of | brickwork, there is no outer layer of brick/blockwork - there doesnt | look room for it under slope of roof. This means, that inside the | first floor rooms, the brickwork over the windows - about 300mm high - | is only one layer thick, which is probably why it seems to create cold | surfaces of condensation, etc. Am I right in this conclusion, and is | there any way to help insulate the area over the windows? Advice much | appreciated.

When I had soffits done the bricks above the lintel fell out. :-( Stuff the gap full of glass fiber, but make sure the loft space is still ventilated.

[Pufter]

My house is the same - about 300mm of blockwork above the window on th inside, the top of the window is level with the soffitt on the outside When I had new windows put in there was just a gap above the windo frame into the loft above. The window frame pretty much filled this with a piece of quadrant/sealer around the top, & sides. Never reall thought about the heat loss consequences of this, but i've never ha any problems with condensation or anything

-- Pufter

[meow2222]

Although more likely, you still shouldnt get condensation on 4" walls. Maybe your interior RH is on the high side for some reason.

NT

[keith_765]

I think the cause of the problem is cold air hitting the inner wall skin. It was general practise in the 60s to lay fibreglass on top of the ceiling up to the edge of the roof slope. Present day regs, the insulation is taken over the wall plate and meets a vertical layer on the outer skin of the inner wall to stop cold air causing condensation on the inner wall. If you can get some fibreglass over the wall plate and down to the top of the outer wall, this should cure the problem. There should be enough room to thread insulation between the underlay felt and the wall plate. It might be better to get some 50mm or 2" fibre glass bats or polystyrene sheet, they will be stiffer and should be easier to push down.