Another loft insulation question on an old house!
Another loft insulation question on an old house!
Author
Discussion

Om

Original Poster:

2,130 posts

99 months

Friday 18th July 2025
quotequote all
I didn't want to hijack the other thread, but we find ourselves with a related question. It is a house that belonged to my partner's father that she has just inherited and we are about to refurbish with an eye to renting once complete.

We ventured up into the loft area to clear out and found that there is minimal insulation up there - it being very old, likely 1980s - and having flattened to a few cm... The centre has been boarded over for storage with the sides open to the rafters. The house is about 90 years old with clay tiles that have no felting - just straight to the battens - the gable ends are rough cut wood with no felting/membrane.. I don't think it has been touched apart from the odd replacement tile since built. It seems dry/sound but is obviously well ventilated with quite a few large old wasps nest up there!

Clearly we want to improve the insulation but are unsure of the best method. Remove the boarding and add a suitable amount of insulation? If we want to retain some storage would using some kind of loft legs/stilts make sense or just remove the boarding completely (it isn't needed really)?

Is there anything we need to consider/bear in mind?

Thanks!

dhutch

17,461 posts

218 months

Friday 18th July 2025
quotequote all
Sounds about right to me.

What is the wall construction, solid or cavity? Any sloping 'skeilling' ceiling areas?

Om

Original Poster:

2,130 posts

99 months

Friday 18th July 2025
quotequote all
dhutch said:
Sounds about right to me.

What is the wall construction, solid or cavity? Any sloping 'skeilling' ceiling areas?
Solid brick walls and there are some steeply sloped edges to the ceilings at the front/rear/side (the house is in a T shape).

dhutch

17,461 posts

218 months

Friday 18th July 2025
quotequote all
So my thoughts on this are.

- Loft insulation is cheap, easy to fit, and low risk. So having a reasonable amount is good.
- However there is no point in going totally mad when you have solid walls and uninsulated skeilings
- Therefore somewhere between 150-250mm is about where I personally might pitch it.

Then look at the options for the skeilings.

In my last house, I look down the skelling plasterboard from the inside, room at a time, and fitted 50mm insulation between the rafters, and the 50mm over the top of the rafters, before reboarding and got some one in to skim the whole ceiling which also 'removed' the artex. With 3x2 rafters this left a good inc between the felt and the foam, and I extended the foam between the rafters up into the loft enough to hold back the loft insulation reasonable well.

I was also blessed with cavity walls, so had then filled with eps balls which also worked really well for me.

ssray

1,263 posts

246 months

Friday 18th July 2025
quotequote all
1930's house opposite had no roofing membrane type stuff.
He had the tiles removed and replaced with membrane under the tiles, even without extra insulation it was much warmer and much less dusty, Also before everything up there had to be covered in tarpaulin as rain would get past the tiles.

He's now gone further and insulated under the tiles, added lath and used celotex type stuff to insulate it

2 sMoKiN bArReLs

31,629 posts

256 months

Friday 18th July 2025
quotequote all
Om said:
I it being very old, likely 1980s
No help, but that made me feel very old...until I read the rest of the post hehe

dhutch

17,461 posts

218 months

Tuesday 22nd July 2025
quotequote all
2 sMoKiN bArReLs said:
Om said:
it being very old, likely 1980s
No help, but that made me feel very old...until I read the rest of the post hehe
Dont worry, you're only old for loft insulation! (late 80s child)