40mm basin waste

[fatbob78]

Does anyone know where I can get a 40mm basin waste?

I bought a 32mm believing that this was the only possible size, and it was the same size as the one I was replacing. But when I took the old plughole out it was apparent that the hole was much larger than 32mm and whoever had installed the sink originally (10+ years ago) had used a generous amount of silicone to make up the difference (v messy to clean up)!!

So, can anyone point me in the right direction, or should I do the same and bodge it with loads of sealant?

Your comments would be appreciated.

Thanks,
Bob

 

[Charnwood]

Slotted or unslotted?
Minimum length required to get through basin and attach to trap?
Maximum size flange you can get away with? (Std flange for a basin waste - 61mm. Std for a bath waste - 73mm)

 

[fatbob78]

Slotted
Minimum length about 70mm
Maximum flange size probably about 75mm

The diameter of the new bath waste I bought is probably ideal, if only it was longer and didn't have the overflow pipe coming off!!

Bob

 

[Charnwood]

The bath waste you've got sounds like a 'five star' - plastic body with a stainless steel screw down flange. Not suitable, as you said.

You want a Belfast sink waste. They have an 81mm flange, are about 80 to 85mm long, are slotted and are 40mm/11/2". Actual diameter of thread is about 48mm.

I'm fairly sure you won't find a 40mm/11/2" waste with a flange 75mm or smaller, other than a flush grated shower waste.

What is the diameter of the hole in the basin?

 

[fatbob78]

The basin hole is about 45mm

 

[Charnwood]

The diameter of a 32mm/11/4” basin waste thread is about 42/43mm. This would be the correct size for a basin with a hole of 45mm.

How about is “about 45mm”?

 

[fatbob78]

Ah. It looks like I might have been stupid then......

I expected the waste to fit snugly in the hole and because there's a 2-3mm gap all the way round I assumed this meant I needed the next size up i.e. 40mm waste.

So, is it normal to have a gap then? And if so wouldn't any potential overflow water end up in the gap, sitting below the slots?

Another reason why I thought I had the wrong size was that when I tried it out, the water also leaked underneath the flange, but maybe this was because I didn't use enough silicone, or should have put a rubber washer between the flange and the basin.

Apologies if I've wasted your time, but I really do appreciate your help.

Bob