"Ian_m" wrote in message
...
"John" wrote in message
...
My daughter's partner is getting a new bath fitted soon - what is the
recommendation on the thickness of an acrylic bath that is going to be
used for showering in? I realise that too much flexing will lead to
problems sealing the edges.

I once replaced a 5mm cheapy bath (in a house I bought), used for
showering, that was always leaking at the silicone sealant, as the bath
just flexed and pulled away. Also eventually leaked at plug hole as
fibreglass started to delaminate.(delaminiation can be bodged with plastic
padding...).

Was replaced with steel bath that had none of those issues.

Current bath is 8mm (carionite) and doesn't flex at all. A plumber who
quoted for the bath room said he would only fit 8mm (or steel) if being
used for showering as he was unable to guarantee any silicone sealing.

My brother, who is an ex-plumber, said he often bodged 5 & 6mm baths in
place by filling up underneath with expanding foam to stop any movement.
Obviously leave space around taps and drain and seal floor with polythene
to stop it running into the room below (sounds line voice of experience
!).

Sounds like incorrect fitting to me..
baths normally have a chipboard/ply base stuck to the bottom..
if this is correctly supported standing in the bath has zero effect on the
silicon seals.

Thin baths flex when filled with water not when showering IME.

Also an 8mm bathe flexes if it isn't supported properly.