Loft insulation with sloped ceilings

[bobo29]

Am looking to improve my loft insulation following recent removal of a water tank. There is already a bottom layer of insulation installed by the previous owners, in between the joists only.

Not quite sure how to describe it, but the roof fits lower than the side walls and we have exposed rafter feet. So in the loft we have a very small gap (about 10 cm) between the top of the plaster of the ceiling and the inside/bottom of the roof (first picture). To help you get a better understanding of what's going on I've attached a picture (second picture) of the ceiling in the upstairs rooms which slopes about 45 degrees at the edges of the house.

What I'm trying to work out, is what is the best way of insulating this? I've been told that insulation shouldn't be compressed for its effectiveness and also if I were to stuff it in this gap on the sloped section I'm in danger of it getting damp and also possibly causing condensation. I could possibly just put topup insulation at right angles to the joists on the flat section but if I leave the sloping sections uninsulated does this defeat the point?

Many thanks in advance.

 

[rich42]

My house is a similar design and I am contemplating the same issue as yourself.
I am looking at a full roof refurbishment later next year as I dont have any felt under the tiles either. I was looking at adding foam type insulation between the rafters while the tiles are off. I would be interested to see what people think would be a solution to your problem.
Regards, Rich

 

[gonch69]

Easiest option is to add celotex or kingspan to under side of plaster board then reboard on sloped section

 

[foxhole]

No reason it should be damp or cause condensation, rigid insulation as suggested.

 

[bobo29]

Thanks for the replies all. Will investigate some rigid insulation.