Shower access panel (tile on ply)

[j1979]

I am currently fitting a bathroom, and have been limited to an electric shower. I choose an electric shower with a remote pack (Triton T300si) and build stud wall to house this remote pack.

It the stud wall was covered with Aquapanel but there needs to be a 2 tile access hole.

To cut a long story short there is an access hole but in order to be able to fix the access panel securely I needed to use WBP ply. because screwing Aquapanel at the extreme edges causes it to break up.

So I need to just need a way of fixing 2 tiles to the 12mm plywood to complete the access panel for the shower.

but I have read many recommendations of what to prime it with.
PVA is a bad idea, Some recommend BAL APD but the data sheet say plywood (floor) with no mention of walls. Others say BAL SBR but the datasheet for that does not even say suitable for plywood at all.

the adhesive I am using elsewhere is MAPEGRIP PLUS "water-based paste adhesive based on acrylic resins."

Can't i just paint the plywood to seal it with an acrylic paint ?

Does anyone have any specific products or ideas?

or should I give up on using plywood here and look at a different approach?


Thanks in advance!

 

[ree]

Your post confuses me - but the bits that i think i can answer are:

that you double up on corner studs to gain fixing space, and fix noggins for horizontal edge fixings.

Add extra studs to pick up boards or enclosure jambs.

No ply would be needed.

Shower units or valves are first fixed before any coverings are fixed.

The elec unit is final fixed onto the tile.

Access panels are, if used, typically on the other side of the shower unit/valve wall.

The Aquapanels are fixed straight onto the studs, sometimes they have a membrane behind and sometimes they have a "painted on" tanking.

Best practice is to always use powdered adhesive.