PIR as a Showerlay plinth??

[connick159]

Hi all,

 

I'm working on the ensuite now and have seen this Marmox Plinth as a good option to build a shower tray up on top of the slab so I can get drainage underneath. (cant dig into the slab so have to go above it and out the wall for the drain.) The plinth is fixed to the slab with a flexible, cement based tile adhesive.

 

On top of that plinth I would then install a showerlay such as this... Marmox showerlay.

 

My question is: Could I substitute the plinth with some leftover 100mm Celotox PIR insulation? It seems like essentially the same thing. Is there any reason why this is a bad idea?

 

Thnks in advance.

Edited October 8, 2021 by connick159

[connick159]

For reference - decided to order the plinth and shower lay as above.

[Olf]

You did the right choice: XPS have twice the compressive compressive strength of PIR and does not degrade in contact with water