Architect recommended 150 mm total depth Kingspan PIR Floorboard insulation

[CalvinHobbes]

Does floorboard insulation vary from Kooltherm? Looking at an ad on gumtree for the latter.

Also can we use insulation we get off gumtree if it matches the description or is the equivalent of ?

Also can we add 2 different mm depths to get the right one? I see you can buy 40mm floorboard insulation. Will it matter if it means there are 2 levels of foil?

Sorry for all the questions!

 

[Iceverge]

Is this under a concrete slab or for a suspended timber floor? 

 

Assuming it's under a slab. 

 

You can use layers to build up to the required depth. I think using at least 2 is a good idea to allow joints to be staggered. 

 

Just adjust the substrate or covering slabs depth to compensate for variations in the insulation depth.

 

Second hand stuff is fine so long an your building control can see it is a certified product. 

 

That kooltherm is k8, for cavity walls. I'm not sure of it's compressive strength. It's probably fine.

[CalvinHobbes]

Thanks, kinda thinking i wont risk buying it in case its deemed unsuitable or makes the u value worse. I hadn't considered the compressive strength.

[MikeGrahamT21]

Layering is fine, and generally a good idea.

 

Kooltherm is the best product for getting a lower u value, and has 150kPa compressive strength, so it depends on what weight you are putting on the floor.

 

150kPa converts to around 15ton per m2, which would be an immense load to have on a floor.

 

K8 their cavity product has a CS of 100kPa, so will be around 10ton per m2.

Edited January 3, 2023 by MikeGrahamT21

[Iceverge]

100kPa should be fine. We used EPS with a compressive strength of 70kPa