Shower tray fitting - boxing in compression waste?

[MICH43L]

I'm replacing a shower tray - the old one had push fit waste fittings below the floorboards.

I've used the old waste pipe, but I'm a bit nervous about using compression fittings and sealing them in. They don't leak at the moment but in ten years time...?

Any harm in using silicone to seal tbe threads? Or would you rip it all out and use solvent weld (I'd need to replace the pipe out through the wall and into the stack).

 

[MICH43L]

The offending article... Slightly wonky angles on the joints.

 

[Madrab]

If it's at all possible always use solvent weld under floors.

If not then use the best fittings possible, that would be McAlpine IMO. I wouldn't use floplast. Never go cheap or quick when it's hidden under a shower.

 

[Hugh Jaleak]

Never known compression waste to start leaking unless disturbed, but if it's going to mean ripping half the house apart to get to it in future, I'll second Madrab, and replace with solvent weld, at least as far as is practical.

 

[just pumps]

The threads do not form a seal so no point in using silicone