Can I put UFH heating over resin shower tray & plywood?

[Mouldy]

Ive used Devi over ply, concrete and Lux boards. However as tfs has said, if in doubt check with the manufacturer's tech departments.

 

[Bucks.]

Thanks again Guys for your help,
If needed I will speak to the manufactures tomorrow, they have all obviously been closed over the Christmas holidays, so I have been having to rely on what I can find on the web.

 

[Alberta Stone]

Thanks again for the replies,

I'm not looking for an easy anyone can do diy kit, I am wanting the best possible job that will last pretty much forever, which I am more than capable of doing, once I iron out all the ins & outs if you get my gist.

If you are willing to go that far then just glass the whole floor area with fiberglass resin and cloth, go up the wall about 6 inchs and then after all the pinholes are sealed up you will have the bentley of waterproof floors and far cheaper than a precast pan and it will be monolithic (no seams) so you can be pretty confident that it will never leak.
Then you can put whatever you wish onto it.
Just build up the plywood heights first.
Recess the glass you cove up the wall so that you don't end up with a bulge where the wall material would ride over the cove.

 

[Bucks.]

If you are willing to go that far then just glass the whole floor area with fiberglass resin and cloth, go up the wall about 6 inchs and then after all the pinholes are sealed up you will have the bentley of waterproof floors and far cheaper than a precast pan and it will be monolithic (no seams) so you can be pretty confident that it will never leak.
Then you can put whatever you wish onto it.
Just build up the plywood heights first.
Recess the glass you cove up the wall so that you don't end up with a bulge where the wall material would ride over the cove.

Well maybe thats a bit to much for me

 

[Alberta Stone]

Well maybe thats a bit to much for me

LOL....probably cheaper however.....fiberglass is really not that hard to work with.

A possible issue you will encounter is the fact that all the liquid waterproofing materials I am familiar with do not adhere well to plastic. They dry and then can be pulled off with relative ease.
So, unless you can find a different waterproofing that will adhere to plastic, or maybe scarify the surface so that it will key itself onto the surface........

 

[Bucks.]

Do Devimat actualy say that the 150 should not be used with ply?

Been looking into it a bit more (Things are a lot clearer now) :hurray:
Devimat state
The devimat 100 Series is ideally suited to timber based floors.
The devimat 150 Series is ideally suited to heating tiled concrete floors.

Warmup state
When fitting the underfloor heater onto a timber subfloor, the floorboards or chipboard must be over-boarded with a suitable Warmup® Insulation Board or 18 mm WBP plywood. Existing floorboards must be fixed securely and, if necessary, pre-levelled with a latex/cement smoothing underlayment to give a flush fit for the WBP plywood or the Warmup® Insulation Board. Ply must be screwed at 200mm centres and installed as per BS 5385: Part 3 Clause 14.4.
Warmup® Insulation Board must be fixed with flexible tile adhesive. For best performance the board should also be secured with five screws and penny washers per board.
Warning: Fixing ply directly to the joists may not provide a sufficiently stable floor finish to accept tiles; fitting tongue and groove flooring and then over-boarding with ply or Warmup® Insulation Board is recommended.

Enermat State
The Enermat is primarily designed for installation on concrete floors. If layingEnermat on a wooden floor, all floors must be sheeted with Wedi board, Knauf Aquapanel or similar cement covered board which is compatible with heated floor systems or sheet the floor with 15mm WBP or Marine plywood, fix with screws at 200mm centres and then skim with 2-3mm of flexible tile adhesive and allow to dry, then proceed as installation for concrete base.

My Conclusioin
Pressure treated floor joists with Kingspan insulation between joists, area around shower tray T&G floorboards overboarded with 18mm WBP plywood, shower tray installed flush with plywood floor, walls boardered with Marmox 12.5mm tile backer boards, Tank Plywood floor inc showertray (I may also tank the walls in the main shower area, even though they should be waterproof if installed correctly) Then eventually 150w UFH (not 100% decided on what make yet)

Now for what to tank the floor with, I think I should maybe start another thread for this one.

THANKS for all your help & advise Guys its much appreciated