Resealing shower room

[Pelirocco]

Our motorhome has a wheel arch in the shower room and the shower tray has come unstuck between the arch and the wall ,what should we use to reseal ?
I have also noticed a small crack at the edge by the toilet
As my husband is a bit of a bodger it needs to be fool proof
Thanks

 

[IRHP]

I'd use CT1 to reseal it. Sticks to anything and eveything, silicone doesn't. It's a great sealer and adhesive. He may want to try working with a test bit first. It's not the easies to work with or smooth off. Plenty masking required and a tool for smoothing, definitely not a finger.