Insulating joist for suspended floor with Celetex

katy123

Okay, i think I've managed to piece it all together. We will first remove the floorboards then install celotec GA4000 or XR4000. I've been advised by Celotex technical to install a 500 gauge polythere seperator. Does anyone know if this is the same as a breatheable membrane of vapour barrier? I'm struggling to locate one on screwfix. Also, would I put this seperator before I install the floorboards or after the floorbooards?If it's before, then as I screw the floorboards back on, it will penetrate the seperator.

Celotex couldn't advise me much on the seperator, thanks.

ceredigion

500 gauge polythere= DPM (damp proof membrain)
FWIW, I think Celotex technical are wrong. you need to ascertain where the dew point will be. But i would be using a breathable option.

katy123

ceredigion wrote: »

500 gauge polythere= DPM (damp proof membrain)
FWIW, I think Celotex technical are wrong. you need to ascertain where the dew point will be. But i would be using a breathable option.

Thanks Ceredigion, can you please provide a link as to what you think we need as a starting point? Screwfix or tool station is a good starting point for my research, many thanks.

TheCyclingProgrammer

My understanding when I researched this a few years ago is that the vapour barrier should be on the warm side of the insulation and ideally you!!!8217;d have some kind of breather membrane on the cold side.

Furts

katy123 wrote: »

Thanks Ceredigion, can you please provide a link as to what you think we need as a starting point? Screwfix or tool station is a good starting point for my research, many thanks.

Celotex, Kingspan and so on all do technical drawings showing all conceivable uses of their products.

I have a pocket book, dead easy to follow the coloured drawings. This is produced by Celotex, and these are available on the shelf at builders merchants and are free of charge. If you ask a merchant, and dangle the carrot of wanting a quote for the materials, it should be a certainty that a book will be available for you.

The info is bound to be on the web - you do the simple searching.