Hello
My dormer bungalow was built in 1994 and the "eaves" space of approx 2m either side of the building is boarded out with chipboard and minimal insulation beneath. Worse, due to the joist height (approx 200mm?) there was quite an airgap above the insulation and the chipboard. The old insulation (yellow stuff, like rockwool) was approx 100mm. The 100mm of air above was then open to the attic space, soffit vents (where they weren't blocked with insulation!) and also the open cavities.
I've blocked the cavities at the top with insulation, opened up the soffit vents, and blocked up the joist gaps with additional insulation which overlaps into the insulation atop the cavities. Then, I've added 200mm of insulation on top of the chipboard (sacrificing the storage area but insulation seems more important).
Sorry if this is hard to follow, but I'm now concerned that I've created a potential for interstitial condensation between the two effective layers of insulation?
On the flip side the temperature of the chipboard on the attic side was 18c and now it's covered in insulation the topside of the insulation is 5c according to my thermal camera so it's quite a difference.
Any advice or words of wisdom appreciated and welcome!
Thanks
Mike
My dormer bungalow was built in 1994 and the "eaves" space of approx 2m either side of the building is boarded out with chipboard and minimal insulation beneath. Worse, due to the joist height (approx 200mm?) there was quite an airgap above the insulation and the chipboard. The old insulation (yellow stuff, like rockwool) was approx 100mm. The 100mm of air above was then open to the attic space, soffit vents (where they weren't blocked with insulation!) and also the open cavities.
I've blocked the cavities at the top with insulation, opened up the soffit vents, and blocked up the joist gaps with additional insulation which overlaps into the insulation atop the cavities. Then, I've added 200mm of insulation on top of the chipboard (sacrificing the storage area but insulation seems more important).
Sorry if this is hard to follow, but I'm now concerned that I've created a potential for interstitial condensation between the two effective layers of insulation?
On the flip side the temperature of the chipboard on the attic side was 18c and now it's covered in insulation the topside of the insulation is 5c according to my thermal camera so it's quite a difference.
Any advice or words of wisdom appreciated and welcome!
Thanks
Mike
