Question for plasterers

[Rollin]

I'm in the process of renovating a room in our house and I'm battening out the walls to enable PIR insulation to be fitted.
I'd like to line the walls with Marmox type boards to maximise insulation.

I'll be fitting the boards and I know they can be plastered but I was wondering if it's more hassle for a plasterer compared to plasterboard?

I guess the question I'm asking is, is it commonplace these days for plasterers to be faced with rooms lined in this way?

[Little Lofty]

What type of Marmox board is it? The only type I've seen are for tiling on.

[Rollin]

Either Marmox Multiboard or Jackoboard Plano

https://www.jackon-insulation.com/products/detail/...

https://www.marmox.co.uk/products/multiboard

I must add that I've done this before in a bathroom several years ago, part of which was plastered.
Back then, the boards were marketed as tile backer boards, but now they seem to be more referred to as construction boards able to accept several types of covering.

[wolfracesonic]

The Marmox FAQs say you can plaster directly onto it, no primer needed. Do you need the water resistant qualities of the Marmox? If not, could you use a 22mm EPS plasterboard, if you can afford to lose the thickness. It would be a lot cheaper.

[JoshSm]

The Marmox board at least should be fairly friendly for plastering, it has a strong key on the surface and being a cement skin over something waterproof will have very controlled suction hence no need to prime it.

Compared to some of the things people try to slap plaster over it should be trivial.

[_Hoppers]

It looks like the Marmox stuff is XPS not PIR?! Have you looked at Kooltherm K118, it's got a much better thermal resistance?

https://www.kingspan.com/gb/en/products/insulation...

[dhutch]

wolfracesonic said:

Do you need the water resistant qualities of the Marmox? If not, could you use a 22mm EPS plasterboard, if you can afford to lose the thickness. It would be a lot cheaper.

Or even better, fit 10-20 mm thicker PIR foam and normal plasterboard, cheaper still!

[Rollin]

Yes, I've used PIR between the battens. The marmox is to go over the top. Minimal thickness is important for this. It could be the difference between a standard sized kitchen unit or much more expensive bespoke size

[Vanden Saab]

I use these boards in bathrooms and we go to the nearest battern past the shower area and get the part outside plastered. It should not be any more expensive and the plasterer I use loves it as it is easy to plaster on.

[Pheo]

Suspect the issue you will have is less will it work but more will a plasterer do it

Tend to be creatures of habit because they’re in demand and you don’t want the callback because you did something unusual…

So I’d make sure you’ve got one lined up before you do it.

[dhutch]

Pheo said:

Tend to be creatures of habit because they’re in demand and you don’t want the callback because you did something unusual…

So I’d make sure you’ve got one lined up before you do it.

Its hard to get any trade to turn up let along ahead of the work, or even when you need it to be done.