Insulating Eaves over wall gap? Information, help, tips and advice on cavity walls, ceilings and lofts etc....

[grobbarg]

Hi, hope someone can help - we are currently insulating the eaves space in our house, both for sound proofing (next to busy road) and thermal. The house has granite external walls and lath/plaster inner walls with approx. 50mm gap between. At the eaves floor level I've laid Rockwool between joists over and up to the outer edge of the granite wall top, using baffles to keep the insulation away from the soffits and roof boards. This has greatly reduced the noise reverberating down the walls and already noticed 5 DegC increase in temperature at ceiling/wall.

However, I'm wondering if the gap between the walls will remain sufficiently ventilated to prevent condensation build up if insulation is sitting on top?

Any advice greatly appreciated...

[welsh brickie]

only time will tell keep checking every couple of weeks

[2tellytel]

I am speaking as a person who is not an advocate of cavity wall insulation , cavities came in for a reason.

Therefore I would not lay the insulation over the gap, but then it is just my opinion.

Also when insulating lofts make sure the loft is well ventilated

[grobbarg]

OK Cheers WB, just concerned we get mould growing somewhere we can't see or get to.
I suppose I could hang a humidty sensor down the gap to monitor, but that might go up and down with the weather anyway.

[grobbarg]

I am speaking as a person who is not an advocate of cavity wall insulation , cavities came in for a reason.

Therefore I would not lay the insulation over the gap, but then it is just my opinion.

Also when insulating lofts make sure the loft is well ventilated

We really need to have some kind of insulation for noise and cold, I wonder if we could place some plastic corrugated (cut from roofing) panels under the insulation from wall to soffit to allow air flow up through the wall from solum to soffits?