Loft insulation - can I use boards?

[ConfusedByThisShit]

Quick question for anyone that's insulated a loft before....

Can I use Celotex boards to insulate a loft floor? And is it as simple as cutting them to fit between the beams and just slotting them in?

We have a survey booked in for next Weds. DP has just gone in the loft to make sure there's easy access and remembered that when we had a squirrel invasion earlier in the year, they ripped up all the insulation. I can't go in the loft (for health reasons) and honestly, we just totally forgot about it!!! We sorted the squirrels and repaired the roof.....but forgot to redo the insulation.

DM has some spare insulation boards - photo below. Money is desperately desperately tight at the moment so I'm wondering could I just cut up this insulation boarding and use on the loft floor? I appreciate the surveyor will flag it as less than the ideal, but it's better than nothing, surely? My house is a bit of a fixer-upper - the buyers are planning on fitting a new kitchen and bathroom, and new carpets so I'm hoping it's not a deal breaker.

Do you think these insulation boards would be OK to use?

Yes you can do that no problem, the solid board type is better than the soft stuff it’s just more time consuming to fit it .
those sheets were about 50-60 pound last time I had some …… snap them up quick !!!!!! 😀

Stick with rock or glass wool. Rigid boards are designed for this application.

Grrr. Rigid boards are not designed for this application.

Mineral wool is a fraction of the price, is quicker and easier and reduces sound transmission across room.

As above. I think you can get rock wool for £20 a roll.

I don't know how much you would get ebaying those boards.

Ebay or marketplace the boards and spend the same on loft roll.

The trouble is to get enough insulation to cover the loft, I'd need to spend probably in the region of £120 or so. And tragic though it sounds, I just don't have that spare at the moment. In fairness, even spending £20 wouldn't be ideal.

Once we sell this house, our finances will be fine but at the moment things are bloody dire. Hence why I'm side-eying the insulation boards and wondering if they'd suffice.

The other problem is that the survey is in 4 days time - I don't think I've got enough time to flog the boards and then buy the regular stuff and then fit it.

Without wanting to sound all woe is me, we've had so much going on here in the last month - stepdad diagnosed with cancer 3 weeks ago and had surgery plus several trips back to A&E (I'm the carer), putting this house on the market and unexpectedly getting a buyer within a week, two autistic DC (one with high needs) struggling with change/people in the house for the sale, I'm trying to work F/T, DM has cerebral palsy so she needed extra care/support when stepdad was in hospital......the bloody loft just slipped my mind. I could kick myself!!!

You've £300 to £400 of boards there.

Don't sweat it, the sale won't fall through because of a bit of insulation missing.

How are rigid boards not designed for loft insulation? You don’t see it very often because it’s a lot of work to fit around cables / pipes etc and takes ages to fit. But it’s perfect as loft insulation and very good for where space for normal glass fibre insulation would be too much.

Pity you don’t live near me as i need some and would buy it off you ☹️

And how did she end up with so much spare ????

Thank you @Daftasabroom - think I'm just stressing because this is such an important sale (for long and complicated reasons I won't bore you with). The house has great bones but does need work - and it's been priced to reflect this. I probably need to chill a bit haha!

@Diyextension - thanks so much, this info is really helpful!! We've just finished a big building job. This is going to out me on here to anyone who recognises my story from my other thread with my regular username but sod it. We've extended the main house on our new property and built an annexe for DM. Basically both DM and me sold our properties to buy somewhere bigger together because of her significant care needs. We opted for a modular build (that's the outing bit for anyone who read my previous thread!) - and for some reason we had a load of boards left over. There's actually two fewer boards than showing in that photo but still a nice pile. We don't need them for anything else so seems to make sense to use them to insulate this loft! I think the modular company lost the plot slightly when ordering - we've got about four big bags of concrete left here, we had one brand new spare window they left plus some other brand new frames (which we have given to someone else now), this insulation and some other bits and pieces. Think they must have been drunk when ordering the supplies haha

Building regulations call for 100mm of acoustic insulation in std walls and above ceilings. So if your ceiling is the underside of the loft you need 100mm of acoustic insulation there too. You can buy roll/slab that does both.

We have 150mm between ceiling joists, crawl space, then have an insulated roof with 150mm wool between joists and then another 120mm rigid boards over the top, the low emissivity membrane above.

Our walls and loft are full of this

Hi @ConfusedByThisShit the reason they couldn't put the cavity fill in the front and back is likely because it's side to side window! 😀

Looking at the pics it's standard cavity wall, just not a lot of wall, mostly window.

It may be that the first floor wall below windows is timber frame, hard to tell without an onsite inspection. I really really wouldn't worry though.

Sorry wrong thread

Just leave the loft and flog those boards on a local marketplace site to get some cash.

The sellers might reduce their offer by the cost of loft insulation. Maybe £500? It's not structural, easy to resolve, uses relatively cheap materials and a day's labour.

I did my own loft insulation recently and took two long days, but I was moving the stuff in the loft around, removing knackered felt and cleaning as I went.

What @Rollercoaster1920 said.

@Daftasabroom and @Rollercoaster1920 - thank you both. I'll convey this to DP - he'll be delighted not to have to do more work up there as it's very hot and airless!

He's managed to get all of the old, dirty stuff out today - also can't believe how much junk was in the roof!!! I've got bags and bags of stuff down here to take to the tip/recycling place!

The good news is that DP says the loft looks structurally sound, no issues with the wood or the wiring. I was worried about that because the squirrels really were little bastards to get rid of, but DP has looked everywhere and says it looks completely fine.

The house was priced very competitively anyway because we want to sell quickly, and then the buyers have had another £10k off because they want to fit a new kitchen and bathroom (which isn't strictly essential but I can see why they'd want to). The house was only on the market a week but with the declining health of DM and stepdad we really do need to move quickly so we accepted the offer. There were other people interested but they were faffing around whereas this buyer was on the ball with their paperwork, no chain, and just ready to go. Honestly though, they're getting a bloody good deal already. I would be a bit disappointed therefore if they wanted to argue about another few hundred pounds for some bloody insulation but equally, it would be a straight yes - I'm not going to piss about and argue for such a trivial sum.

I'll just be relieved if the survey goes through OK - you never know what might be lurking!!