Solid loft insulation

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Hi,

Bought a house (victorian semi) with two loft/attic rooms. One was already converted, the other bare brick and pitched roof.

The rafters are about 70mm deep, with black bitumen-type felt which looks to be in fairly good condition. The previous owner had started putting in 80mm foil backed Kingspan between the rafters, and left me a few sheets.

So I've continued the job, used up the rest, with a view to building down the batons by a couple of centimetres and boarding the ceiling.

Started reading about it all, and it turns out I might need an air gap. At present there's no air gap at all. Just tiles on felt type stuff and then insulation filling the rafter gap.

Have pulled out a couple of the blocks of insulation, there's no sign of damp.

Do I rip it all out and start from scratch?

I need to do the other room at some point, the plan was to beef up the insulation in that one too. Not sure now, but I'm going to lose a lot of headroom if I have to insulate below the rafters.
 
Last edited:
Yes you must have an air gap!
The easiest way to do this, run a batten down the rafters tight to the felt this will guarantee an air gap all the way.
If your rafters are 70mm deep then 50mm insulation is your max.
 
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