Void under resin tray former Drainage and wastage systems and plumbing help, advice and answers

[MilliesDad]

My recently installed solid resin shower tray / wet room former has around 4mm flex across a dinner plate sized area in the middle. It's on a concrete base that was unevenly screeded over. The gap will likely be under 10mm. It has not yet been tanked or tiled but would be a pain to entirely reinstall. Instead of taking the former out I'm thinking to drill a few small holes and inject a solution ( epoxy/polyester resin/ expanding foam) from the top of the tray to fill the voids underneath. Any thoughts appreciated.

 

[stoneyboy]

Hi milliesdad,
Holes in the top will always be a weak point, could you drill the holes in the side and fit a small plastic pipe onto a foam gun to reach the inaccessible areas?
Regards S

[MilliesDad]

@stoneboy Solved - Prior to seeing your post I went ahead and sprayed minimally expanding foam through evenly spaced holes in the former surface while stood on it to mitigate distortion. It seems to have worked very well. The holes will be epoxied prior to the entire tray being tanked. Appreciate your input.

[stoneyboy]

Hi milliesdad,
Thanks for the update, hopefully you stood on the tray long enough for the foam to set so there is no flexing.
Regards S