Insulated Plasterboard Version

redlough

So I am in the process of upgrade on house, budget is a concern with the current price of materials etc. Also have a limited budget as it was an unexpected spend

I have got walls built up and put in 50mm xtratherm insulation in the cavity. The cavity was only 60mm so 50mm was the maximum. So going to install a 50mm insulated board on the walls to top it up. Also going to do air tightness etc(must point out rest of house isn't done but at least start in right direction)

So this is the planned board: https://www.goodwins.ie/products/xtratherm-insulated-plasterboard-63mm-8x4-ft.html?filter_set[]=1413,1419

Need about 15 - 20 of these.

The other option is a Knauf board, the information below I got from the supplier.

I guess I should be comparing the U-value but not sure? the Knauf are costing about half the price but I am just wondering am I just buying something which is not worth it long term?

I talked to builder and he said he has used both and doesn't know the difference but he standardly uses the Xtratherm ones.

Thanks

U value 0.62

Productivity 0.031

Plasterboard KNAUF

10-10-20

https://www.boards.ie/discussion/2058274545/insulated-plasterboard-version

Do you have a link to the Knauf insulated board, and where are you sourcing that from?

The Knauf stuff might not be PIR backed plasterboard.

redlough

https://www.boards.ie/discussion/comment/119959190#Comment_119959190

It doesn't have the foil on it,

Similar to this: https://www.adverts.ie/other-building-materials/insulated-plasterboard-warm-boards-top-quality-house-heating/17167144

10-10-20

That's expanded polystyrene. No contest, not the same game and not even the same pitch. :)

10-10-20

"EPS insulation does not react with concrete or other building materials so don’t required foil to protect

EPS insulation is fully breathable to"

Eh, right....

redlough

https://www.boards.ie/discussion/comment/119961662#Comment_119961662

Perfect will pay the extra

The cheaper stuff, I was going to use on converting a wooden shed into a playroom/office. I guess it will do that sort of job?

sydthebeat

50mm insulation in a cavity with 38 mm insulation internally means youre pretty much guaranteed to have internal condensation issues

redlough

https://www.boards.ie/discussion/comment/119962408#Comment_119962408

Yes. long term want to install heat Recovery

sydthebeat

https://www.boards.ie/discussion/comment/119962859#Comment_119962859

When i say "internal condensation issues" im not talking about internal in the house, i mean internal in the construction of the walls ie behind the insulated plasterboard. Heat recovery ventilation will help, but may not prevent it completely. You need to ensure the vapour does not get into the construction, which is very very difficult.

read here please

https://www.richardsonandstarling.co.uk/blog/interstitial-condensation/

MicktheMan

https://www.boards.ie/discussion/comment/119962976#Comment_119962976

Syd, decent explanation there of interstitial condensation in your link but I do not agree with their use of PIV to counter it (in fact you could argue it might even make the situation worse!). Imo, cMEV is far superior as a whole house solution.