Inperia shower tray installation

[harebi]

Please advise, I going to install an Imperia 1200 x 800mm Slate Effect shower tray. The instructions state to bed it into mortar or cement based tile adhesive. The tray needs to be on a low chipboard plinth. The plinth is made out of the same material as the rest of the floor and sits on a wooden frame.

How critical is the rigidity of the plinth ? Are these trays designed to only be supported around the perimeter ? If the tray is perfectly rigid, then any give whatsoever in the center of the plinth will transfer weight to the perimiter of the tray where it is supported by the frame. Am I overthinking this and these trays are good and strong ?

Thanks in advance

 

[yorksbuilder]

Ensure a solid base with joists and framing/noggins. Ensure the plinth is solidly supported without any give, before you start the tray installation.

also have a look at this:

 

[Madrab]

No chipboard anywhere in a bathroom IMO. Worst decision ever to put a material that literally falls apart when it gets damp/wet into a space that gets damp and wet.

Replace the chipboard with OSB3 or ply, min 18mm thick. If it's upstairs then tank the wet space before tiling and laying the tray.

If the tray is fully flat bottomed and stone resin then it needs to sit uniformly flat to the plinth top, be that with a tile adhesive/mortar polymer adhesives (ma favourite) etc anywhere not supported can lead to stress/flex points and the tray can crack over time.