Suspended Floor Insulation Options - Ground Floor

[flameport]

Will any of the pipe work need lagging down there?

Yes, all of it.
Using the decent insulation, not the cheapo rubbish that's sold as 'economy'.
Secure it in place using cable ties.

 

[GeddyMortgage]

Will do thanks,

I read plumbing pipes should have a clearance of 100mm or so from the insulation too. So sensible just to stick to that as a rough guide?

 

[oldbutnotdead]

Will do thanks,

I read plumbing pipes should have a clearance of 100mm or so from the insulation too. So sensible just to stick to that as a rough guide?

Where did you read that? No problem having pipework through or in loft roll that I've ever heard of

 

[GeddyMortgage]

some online forum post or YouTube video I think …. If it’s in the insulation, why lag it too?

I thought the lagging was to avoid the cold settling on the exposed pipes as the only things that essentially aren’t insulated.

 

[oldbutnotdead]

The insulation on the heating pipes (and hot water) is to keep the heat in- any heat going into the ground floor void is wasted. Insulation on cold water pipes is to stop them freezing up (and yes it'll reduce any condensation on them also).

 

[GeddyMortgage]

I usually get Knauf, as they make the Ecose one, though it is also sold under other brand names at the big chains.


Knauf Insulation Super Top Up 200mm Loft Roll - 5.61m (1217) £25 £4.45 per m2

Knauf Insulation Super Top Up 200mm Loft Roll - 5.61m² | Wickes.co.uk

Knauf Insulation Super Top Up 200mm Loft Roll - 5.61m²

www.wickes.co.uk

It's possible the high price you saw is due to shortages as winter comes and the cold weather starts. Check if the price includes VAT and if you can collect or have to pay delivery.

Summer is the best time to buy insulation.

Just a quick one - that knauf roll says 200mm “top up” and in the description mentions it’s for lofts that have insulation in the ceiling.

Despite that it’s still fine to be used used on its own for my suspended ground floor right? Rather than ‘topping’ something else up?

The reason I ask is because I noticed on wickes they sell “bottom layer” 100mm knauf loft insulation too…. It’s not like these have to be used in conjunction or anything in my suspended ground floor right?

 

[JohnD]

The description is based on typical joist depth in lofts (smaller than in floors because they are not designed for walking on)

200mm fits fine in floors

The one in my pic is slightly thinner than the joists, can't remember the dimensions.

 

[oldbutnotdead]

It's fine on its own. The names are just words, usually floor joists in lofts are skinny so you stick 100mm between then 200 across

 

[GeddyMortgage]

Nice, thanks, that does lessen the confusion.

As on the page for the stuff at Wickes its branded "Super Top Up" But when you click the spec sheet for it. It's then branded as "EARTHWOOL LOFT ROLL 44".... though I assume its all just the same stuff with different packaging.... despite having slightly different lengths advertised vs the spec sheet too?

Wickes - Knauf 200mm Super Top Up Insulation

Spec Sheet

 

[JohnD]

Have look at the packaging to check it is treated with Ecose. The brown, silky stuff in my pic is. I suspect it is all made in the same megafactory.

I would never use yellow fibreglass again, it affects my chest.

 

[GeddyMortgage]

It says it is in the description, and all the thermal resistance/s on the description match the tech sheet too.

Just the tech sheet outlines a completely different named product, google searching that "combi cut 44" returns a different product. So it's just let me a bit confused as to whether wickes one im buying is listed wrong and perhaps worse (as it is cheaper).

 

[JohnD]

Check the packaging in the shop.

P.s.

Now that the cold weather has arrived, hordes of customers will be stripping the shops bare. Same with electric heaters.

P.p.s . I suspect it is all made in the same megafactory.

 

[GeddyMortgage]

Yep, think i've just found the last 15 packs at my local TP....

 

[GeddyMortgage]

Oh one more, sorry.

For lagging i forgot to ask. Does it make a huge difference if it’s the wool wrap type or foam tube type?

 

[robinbanks]

Also comparatively, Celotex GA4000 PIR insulation board comes out about £14m2 for the 100mm stuff. PIR 100mm Celotex

Should really compare it using price per cube rather than per square, but I assume you've done 3x 200mm wools vs 100mm PIR or the equivalent based on the thermal resistance values

For areas where the chief benefit is cutting down on draughts, wool will probably work out better than boards. Getting a good draught resistant install on boards requires careful foaming all round; wool is much more fit n forget

Actis Hybris has advantages but only performs as advertised if the foil face is not touching anything