Thermafleece against roof felt?

[CPEA]

Hi,

I'm in the process of insulating the loft and have high ceilings in the rooms below which follow the roof line into the corners/eaves. The ceiling below is up against the rafters, which are 70mm in depth, but with the roof felt lining sagging a bit it closes to about 60mm in places.

I want to put thermafleece between the rafters - should I use 50mm or 75mm depth? I've been told thermafleece doesn't stop the air circulation so am I right in saying the gap between the ceiling and roof can be filled completely by the 75mm depth and not cause any issues.

Thanks

 

[noseall]

i take it you want to poke the insulation down into the ceiling rake from the loft above? or do you intend removing a section of ceiling/roof?

 

[CPEA]

Poke it down into the gap in the loft...

 

[noseall]

do you know wether the ceiling is lathe and plaster or plasterboard?

 

[CPEA]

lathe and plaster

 

[noseall]

lathe and plaster

ouch!


ramming down anything may knock the ribs off the squeezed plaster between the lathes so be careful, or you may loose the ceiling.

 

[CPEA]

Good point I'll be careful whatever I end up doing, but I was thinking more from a condensation/ventilation point of view.

Reading all the topics everyone is always keen to point out the 50mm gap from the insaultion to the eaves/roof felt...

 

[masona]

Reading all the topics everyone is always keen to point out the 50mm gap from the insaultion to the eaves/roof felt...

'fraid it's the building regs

I'm wondering if it's easier to use polythene insulation slabs if possible?

 

[oilman]

Thermafleece can go the full depth from all the information that's available. The building regs are not written to cope with this relatively new material. Having said that, I put rockwool full depth 20 years ago and have no problem. It probably makes a difference if you live in one of the modern sealed plastic bags.