Flimsy Shower Tray.

I'm using the thetford shower tray with the cut-out for a C200 toilet.It arrived this week and seemed rather too flexible.After a bit of research on the SBMCC,I found a solution and this is how. Using some upvc d section I cut out some discs with a hole saw and glued them to the underside of the shower tray. Then made a cardboard template the same dimensions as the recessed area under the tray. This was then used to cut out a piece of 12mm ply.This was also glued down over the top of the discs. Once the glue has cured this process really stiffens up the shower tray.