Loft insulation

[GeneLovesJezebel]

Anyone know how often you are supposed to renew or top up loft insulation ? My house is about 30 years old and we’ve never done anything to it.
Also, was talking to a retired builder recently and he was saying that he thought the solid insulation would be better as it doesn’t compress with age like the fluffy stuff. Is the solid insulation an option as I’ve never heard of it being used in a loft ?

We had spray foam insulation done in our loft - it made amazing difference to the rubbish fluffy itchy stuff! It keeps the heat really well, you don't feel cold in the loft now and also you don't get bugs in the loft as they can't get in either!

@Aria20 how much did your spray loft insulation cost. My 80 year old mother has just been quoted £6000 for her loft, which take a day to do. Seems a lot, just don’t know how much the materials are.

@Kalgy ours was half that - Greater London/Kent large loft space and they did a good job - this was 2 years ago.

But we had a quote in that price region from a really well known nationwide company but the guy was way too sales pushy and then kept saying if you sign today we'll reduce it to X and when we said no thanks he offered to reduce it again so we knew basically he was just trying to get sky high price out of people. I wonder if it's the same firm...

Also it didn't take a whole day - 2/3 hours max. I think your mum is being taken for a fool by sales people given her age. Get some other quotes as it is really good insulation and worth doing but unless she lives in a huge mansion 6k is a lot!

@Aria20 that’s really helpful, thank you, I suspected as much. It’s a 5 bed house, with a good size loft space, but not a mansion! Alarms bells started ringing for me, so I really appreciate you replying.

My mother is in Kent, so I’d be really grateful if you could let me know who you used. I’ll get a couple of quotes.

My mother likes being independent, so is pleased when she does something herself, just so difficult when you think they’re being ripped off, I just don’t want to undermine her, but equally £6k seemed such a lot. The company also said she had a rat infestation in the loft, so I imagined all the rats running around. There are some droppings, but no live ones, so clearly they’ve been there so needs sorting, but it was sold as it rats were about to take over.

Thanks again for replying, really helpful.

@Kalgy we used home logic. Their prices may have gone up since 2020 - like everything but hopefully not to 6k! The foam will stop any more rats or other pests getting in as well as they do such a thick coating of it!

We have panels of insulation between the rafters and 20cm of the roll out stuff between the joists (the floor of the loft).
I topped up the roll out stuff when we moved in 12 years ago.

Don't use spray foam!

Rafters can rot due to lack of ventilation.
Is viewed detrimentally by mortgage company's and surveyors (when you come to sell)
And a lot of companies that do it are 'scamsters' e.g. £6,000.

Don't use spray foam!

@TwoLeftSocksWithHoles we sold our house with the spray foam 2 months ago and the buyers surveyor didn't say anything negative about it at all said it looked great and he was thinking of getting it done. The estate agent also was asking for the details and apparently everyone who viewed - we had block viewings every 15 mins for the weekend so a lot of viewers - were really impressed with it, we had 14 offers so it didn't put anyone off!

@Aria20

Perhaps things have improved now, but if you search
'problems with spray foam insulation'
There is a catalogue of potential issues.

@TwoLeftSocksWithHoles yes hopefully things have improved then... we had no issues with it and it definitely warmed our old cold house right up - it was old built in 1903 and couldn't have cavity wall insulation so the having the loft as insulated as possible was important.

I'd have it done again if we needed too, current house tho is only 7 years old and we are more likely to want air con installed than any extra insulation!

That’s interesting, the quote was from Home Logic. Uummm, all so confusing! That is though, you have been v helpful.

@Aria20 thank you though.

@Kalgy perhaps the prices have just gone up and probably is a much bigger space as ours was a 3 bed. They were good but definitely get other quotes. I'd avoid evergreen though.

There was a BBC programme a few months ago, a consumer type show, a daytime one, not 'Watchdog' I think and it featured the dangers of using that spray foam insulation. Insurers don't like it apparently and people were finding it impossible to remortgage after getting it done. Yes like a pp said, I think one reason was that it is supposed to rot the wooden joists? Just be careful.

If you don’t use the loft as a room, then all the insulation should be on the floor so it keeps all the heat in the house.

The temperate in your loft loft should be the same as outside to prevent any condensation ( air vents/bricks).

If you don’t have enough insulation on the floor,then the heat will go through and meet with the cold air in the loft. I’ve seen condensation dripping down before due to no air flow.

Id say about 250-300 mm should be fine and the wool/soft stuff is cheaper and easier to fit than the board.

the foam spray is not a good idea as previously said, you loft space needs to breath.

I'd stay away from spray foam. I wouldn't buy a house if it had spray foam insulation. It can go horribly wrong and be an insurance and mortgage issue.

Rats can chew through a wheelie bin , so I’m not sure a bit of foam will give them any trouble

Thank you everyone. I’ll do a bit more homework, you’ve all given me things to think about.

I didn’t get the memo on elderly parents and the time it takes to sort things out for them, so really grateful you given me some guidance.

I wouldn't touch a house with spray foam in the roof. Nor would our surveyor, from what he told me.
Modern standards for the roll-out fibre stuff are higher- you are told to use a thicker layer than 30 years ago. But you can roll another layer on top if the existing stuff is clean and not compressed- you just buy the rolls, cut it with big scissors, and roll it out over the top. Far cheaper than a spray job.
Ours when we came here was dirty and compressed by torching (plaster) falling of the slate undersides. So OH removed it, and put down two new layers of the stuff that comes on a roll, the first between the joists, the second across the top at right angles. Then hessian over the top so if more torching fell as we reslated we could take the hessian out and dispose of it. (The new slating won't have torching- it will be cleaned off any reused slates.)
Solid insulation panels don't compress, and a thinner layer does the same job as a much thicker layer of the roll stuff, but it costs a lot and has to be cut into panels with a saw to a close fit between the joists. A much bigger and more expensive job.

(If you want to be eco-friendly you can use wool insulation, but you need a thicker layer than the fibre stuff and it's more expensive. It's more breathable, but it does have downsides as well. We didn't choose wool because it was always possible that the reroofing would ruin our insulation and we'd have to replace it- if this does happen, we may go for wool when it's not going to be disturbed again once the roof is done).

Just saw this on a house group I'm on and thought I'd show how spray on foam can be a real problem still.

Interesting. We have spray insulation. Clueless about it when bought house 17 years ago. Only know as next door terrace had their roof retiled and roofer told us. Worried me silly googling about it. We think there at least 20 years and so far no obvious problems. However, if wanted to retile might be...
Also, next buyers might have issue if we sold.