Shower tray, waste rough?

[Super_Paulie]

Shower tray from Victoria Plumbing. Under the waste is dog rough, will the seal be ok on this with enough CT1 on the rubber? Trap is McAlpine.

[Super_Paulie]

Actually it looks like this "alternative" flange that came with the McAlpine might make the underside a non-issue?

[Bonner]

Yes, not an issue. Mine was like that, the waste seals on the top but plumbers put loads of silicone on the underside as well.

[Super_Paulie]

1 minute ago, Bonner said:

Yes, not an issue. Mine was like that, the waste seals on the top but plumbers put loads of silicone on the underside as well.

 

Did you use the alternative seal like in the photo or just the 2 singles can you recall?

[Bonner]

I don’t recognise the top hat seal so pretty sure it was two separate seals

[Super_Paulie]

What's your take on this @Nickfromwales?

 

CT1 on the trap rim, add the seal, then a bolt load of CT1 on the seal to fill in all that irregularity. Then bring that up to the tray and screw the top clamp ring in bringing the 2 together? There's a top seal as well, not sure that's necessary.

 

Or use that "all in one" seal which came with it, described as "an alternative seal" that seems to traverse from top to bottom, essentially 2 seals joined together with a middle section, I'm sure you'd have seen them.

 

The trap is McAlpine low profile. 

 

[Nickfromwales]

16 hours ago, Super_Paulie said:

What's your take on this @Nickfromwales?

 

CT1 on the trap rim, add the seal, then a bolt load of CT1 on the seal to fill in all that irregularity. Then bring that up to the tray and screw the top clamp ring in bringing the 2 together? There's a top seal as well, not sure that's necessary.

 

Or use that "all in one" seal which came with it, described as "an alternative seal" that seems to traverse from top to bottom, essentially 2 seals joined together with a middle section, I'm sure you'd have seen them.

 

The trap is McAlpine low profile. 

 

First off, NEVER use silicone for this, and always use a product such as CT1. Silicone has a very short life expectancy in comparison. 

 

Usually the underside of the tray is ground down to a flat surface, waaaaaay better than that pic shows, but it’s not life or death. 

 

As above the underside isn’t of paramount importance as the primary sealing is done at the top surface, but be sure to apply a smear of CT1 the top of the trap before tightening it up against the black rubber washer. 

[Super_Paulie]

On 13/06/2026 at 17:14, Nickfromwales said:

As above the underside isn’t of paramount importance as the primary sealing is done at the top surface

 

it seems pretty important in this instance, the trap doesnt have a screw in central funnel from top to bottom but looks more like it relies on the seals. The bottom seal looks like it does the brunt of the work to me? Id ditch the top seal and use CT1 I'd imagine as well, as I'd want it as low as possible in the recess.