Seconds Insulation for Floors

kenny000666

Hi Guys

We are soon to be completing on our first home! yay!

However with a new home, comes new nightmares, such as responsible spending, and budgeting

One of the first things we are going to do is to replace all the floors with new floor boards, and I figured we could and should probably look into getting the floors insulated. It is a 1930s house with suspended floors, and the EPC states it loses the most heat there. Figured I might as well make this investment now as it will cost more later.

I have been looking at prices for insulation that meets Building regulations, and apparently 100mm of Celotex does it (u value = 0.22). But this can cost a minimum of £12 a sq/m2 and doing the ground floor, 35m2 will cost £422. Baring in mind this is only for the materials. However Energy savings trust, says floor insulation should save me £60 a year, and have a 2 year pay back time (on diy). However on that price there, the pay back time will be 7 years...

I then found something called Seconds insulation. Which to me sounds like unwanted, second hand insulation boards. I could get 15 boards of 100-110mm for around £200. Im thinking that's 1/2 the price! Money Savings!

So my question here is, has anyone used Seconds Insulation boards. Is it recommended over the full price stuff? Insulation is Insulation right? As its going under the floors, can this stuff be risky? Obviously if I purchase seconds boards, and they turn out I have to throw away 2 or 3 pieces, I can always buy the rest from places like wickes to cover the short fall.

One of the main reasons I want celotex over, stuff like mineral wool is possibly I will look into getting underfloor heating installed on top of this, now or later, and if we were to do it later I don't want to have to rebuy insulation..

Thanks guys!

Regards

Ken

phill99

'Seconds' means it maybe slightly damaged ie a corner is chipped off or similar.

It won't be secondhand and is perfectly good to use.

Ken68

Hi Kenny ....I did my suspended floor several years ago, using local supplies. Researched 'Seconds' but delivery cost was the problem, though at that time you could buy a lorry load for £200 plus about the same for transport.From the Midlands I think.
Another problem you will have is cutting the stuff to exact size.

kenny000666

Hi
Thanks for the responses.

I don't think delivery is much of a problem now, £35 fixed to deliver a pallet. Otherwise my dad has a van I could borrow

As for cutting to size might be difficult, could you explain? I would have thought ill need to cut to size anyway if I brought locally?

The current cost for buying supplies locally is £450 minimum.

Thanks

Ken

Ken68

I did mine in between the (not always straight) joists. Maybe would have been better full slabs underneath but only had 18" void.

kenny000666

I just found out, we can't use PIR as we only have 100mm joists, and pipes are quite close to the bottom of the joists. We also have a gas pipe on joist level.

So the alternative is to use battons on empty joists and mineral wool around the joists with piping.

Do you guys think it's a good idea? The u values won't be as good as PIR but at least I don't have to worry about breath ability. I might even be able to lay 40mm of slab below the joist?

Ken68

PIR has to be "gassed" first, or foiled over. So Celotex or Kingspan and Rockwool smells when wet.






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