So the floor is going in.

The second half of the sub-floor area of concrete was done diy by family and friends, using fibre reinforced concrete. A great success, and who needs groundworkers, as long as you have one skilled person and 4 barrows with 4 helpers?

 

150mm of insulation is next.

Planning on 2 layers,  100 over 50, thanks to the very helpful older discussions. as it is slightly cheaper, allows laps, and also better for cutting in isolated pipes and ducts.

Then there will be 50mm Cemfloor with UFH.

 

Maybe use 50EPS for the bottom as it will save about £1,000 and there is a diminishing return as it gets thicker.

On the other hand, for  a big order perhaps PIR will reduce in price enough.

 

Any suggestions as to buying from the national specialist merchants, local merchants or the online companies?

 

I think someone said that PIR only comes via merchants but EPS can come from manufacturers.

 

Total area is 270m2, so pretty well a small lorry load. Perhaps that can come straight from the manufacturer and save double handling by the merchant that takes an easy fee.

 

FYI online prices are, per single sheet, 

PIR 50mm £22    or EPS £11

100mm    £39

150..        £62    (and sometimes 125mm is dearer than 150.)

I got all my insulation from insulation hub, mostly with free delivery to Elgin. 145 sheets of 100mm PIR, for £3500 two years ago, just looked the same stuff is £5500. 

 

That's a lot more expensive.

InsulationHub for me too, as cheap if not cheaper than the likes of SecondsAndCo. 

The PIR I got came direct from the factory, manufactured two days before.  All the Rockwool came from a builders merchant just down the road, for a third the price of me going to builders merchant direct.

https://ecclestons.com

 

For EPS70. 
 

https://bmdgroup.co.uk/products/jablite-expanded-polystyrene-insulation-eps300

 

For EPS300 and other grades. 

Edited August 3, 20224 yr by Nick Laslett

Check the price on 75mm too - it can be had some times for much less than the equivalent 100/50 setup. 

For the same thickness you'll have very different u values for PIR v EPS

I went the 50mm EPS route, and found there was no cost difference to go for the premium graphite variety (which is thermally a useful amount better...)

Insulationhub, cutpriceinsulation and secondsandco,

 

Managed to get a couple of pallet loads from seconds, some had slightly concave edges which the mrs sawed off as I installed, only con is long lead time on delivery, and you have to manhandle it off the wagon.  Insulationhub and cutprice, good prices for retailers and they offload with a dinky forklift for you. 

Edited August 4, 20224 yr by crispy_wafer

Feedback time. Thanks for the info, which was used in further research and contacts.

 

I am very pleased to report that the local, friendly, non-national, builders merchant came out best by a bit. they beat the online specialists by a bit, and delivery their standard £15 instead of £100 or more.

National BM prices silly.

 

The published price was very much higher, but I suppose is reasonable for a single board.

Always worth giving the locals a try.

19 hours ago, saveasteading said:

local, friendly, non-national, builders merchant came out best

And delivered next day!

 

btw, I had the family do a detailed level survey of the slab, and they found a lot more variation than they had expected. As you can't easily change thicknesses, we have gone for 25 +100, all PIR.

Local hollows are being filled with screed to avoid any voids under the PIR.

 

Also btw, the diy concrete slab with fibres has been a great success. Contraction joints cut on day 4 (pushing their luck a bit) and NO signs of shrinkage cracks at all. Recommended for ease and economy. Saved us £2,000 of mesh, plus the labour and nuisance of it, and the pour of 11m3  was done by 5 amateurs 

14 hours ago, saveasteading said:

Local hollows are being filled with screed to avoid any voids under the PIR.

we did the few voids on our basement slab with sand to just level it out a bit. there weren't that many though tbh.

No reason why not, but a few lean mixes in the mixer won't break the bank, and won't scuff.