weak mortar mix? the tray has plywood stuck to bottom of tray and I can't get it off.
Still needs to be bedded on mortar. If you don't and any problems with it breaking, and they do sometimes break if not fully supported, the manu will not entertain you.
The plywood base does not need to be level. The mortar will level it. When mixing the mortar add a squirt of fairy liquid to the mixing water. You need a good smooth mix and this will give a smoother creamier mix that is easy to spread. Don't try to level the mortar too much.It will compress and spread.
will there be a problem if I just sit tray on 1 inch plywood?
I'm not sure how I'm even going to get the tray IN, even without that stuff stuck to it...
And there's the gap (that I need, to hold it !)
It's a heavy beast, and where do I STAND ? I need some sky-hooks...
This is the most difficult thing with trays of this size. You will need someone to help. unless you are a big bstard or want a back massage from the wife.
With a tray in a recess because of the size and weight of it it is awkward. Unless you can borrow or want to buy a couple of these
which will allow you to drop it in, then do as below.
Lay the cement base
Either line up the front of the tray with it standing on its edge and drop it gently into place
or lift the tray in to the back wall and stand on its edge. (Re-spread mortar over the footprints
Drop the tray forward into position and push back and slide it about,tap it down until level across the top (you may need to rake out some mortar from the back to allow tray to go fully back).
How the waste work in will probably decide which way you do it.
Don't bother too much with the masking tape carry on. The mortar will wipe off the tray with a damp cloth after about 1/2 an hour.
Leave to set then pump silicone down around tray to hold it.
Btw if you are building a frame and the wall is brick use these to fix it to the wall
You wanna know ALL my trade secrets
Fancy writing a book Nige