Polyfoam Board

[John Whitworth]

With the flooring now complete, I've next got the first-fix of electrics, and then the ceiling to complete in the garage. However, I'm looking ahead to the wall insulation. Originally, I was going with the timbers onto brick, and infill with Celotex. But after chatting with the council surveyor, I'm now going for drylining with polyfoam boards (of a minimum depth of 50mm including the 9.5mm plasterboard).

I've currently found three types:

- Kingspan Kooltherm K17 52.5mm

- Gyproc Thermaline Super 50mm

- Knauf Thermal Laminate 55mm

Are there any others available that I'm overlooking?

Cheers

JW

[John Whitworth]

I think I'm going for the Knauf board now. It works out the best bang per buck in my opinion.

JW

[Hugo Nebula]

On Sun, 19 Jul 2009 13:07:22 +0100, a certain chimpanzee, "John Whitworth" randomly hit the keyboard and produced:

These are quite different animals. 'Polyfoam' is a trade name for a brand of extruded polystyrene, with a k-value about 0.30W/mK (IIRC). Kingspan Kooltherm is polyisocyanurate with a k-value of 0.22 or

0.23W/mK, very similar to Celotex. Knauf make Polyfoam, so I suspect their Thermal Laminate is a Polyfoam-backed board. Gyproc boards are backed with anything from PIR to expanded polystyrene (at 0.37W/mK, almost half as good as PIR). [The above is all from memory, 'cos it's late & ICBA to look it up.]

If this is a conversion to which the energy efficiency requirements of the Building Regulations apply, then you will need to achieve a maximum U-value for your walls, and therefore a minimum resistance for the insulation material. This is given by the thickness of the material divided by its conductivity, so the better the insulation properties, the thinner the material needs to be. If so, check w/ your BCO to see what resistance value you need. Better still, go to these company's websites - they usually have tables or ready reckoners there.

Lafarge is another p/bd mfr who do insulation backed plasterboard.

[John Whitworth]

Thanks Hugo. The BCO had already confirmed that the Knauf and Gyproc I mention were both suitable. There is little thermal difference between them (1.75 m² K/W and 1.79 m² K/W repectively). Thanks for the Lafarge tip-off. I will investigate their wares tomorrow.

John

[fred]

In article , John Whitworth writes

Isn't that because they are both polystyrene based? The kingspan based one (polyisocyanurate not polystyrene) should be 50% better for the same thickness or 3" polyst performance for 2" polyiso thickness.