Sealing shower waste

[Lee Nowell]

Hi All

I am installing a new shower tray and the waste it comes with has a very thin washer that goes on top of the tray and underneath the waste fitting. Is this enough to seal the top or should I silicone it on to the tray? Or I guess fit it and silicone around it?

Would appreciate your thoughts.

Thanks

Lee.

[Jim GM4DHJ ...]

Post by Lee Nowell
Hi All
I am installing a new shower tray and the waste it comes with has a very thin washer that goes on top of the tray and underneath the waste fitting. Is this enough to seal the top or should I silicone it on to the tray? Or I guess fit it and silicone around it?
Would appreciate your thoughts.
Thanks
Lee.

don't think those thin washers provide the seal .....

[Harry Bloomfield, Esq.]

Post by Lee Nowell
I am installing a new shower tray and the waste it comes with has a very thin
washer that goes on top of the tray and underneath the waste fitting. Is this
enough to seal the top or should I silicone it on to the tray? Or I guess fit
it and silicone around it?

Put some Plumbers Mait around the sealing points, plus long the threads
too, to be sure of no leaks. It's none setting, so comes off easily
where it squeezes out or if it needs to be disassembled later.

[ss]

Post by Harry Bloomfield, Esq.
Put some Plumbers Mait around the sealing points, plus long the threads
too, to be sure of no leaks. It's none setting, so comes off easily
where it squeezes out or if it needs to be disassembled later.

+1
Plumbers mait, I just fitted a sink waste and had small leaking issues
Plumbers mait resolved it.

[ss]

Post by ss
+1
Plumbers mait, I just fitted a sink waste and had small leaking issues
Plumbers mait resolved it.

Video clip on how to use it and seal a waste:

[Jim GM4DHJ ...]

Post by ss

Post by Harry Bloomfield, Esq.
Put some Plumbers Mait around the sealing points, plus long the threads
too, to be sure of no leaks. It's none setting, so comes off easily where
it squeezes out or if it needs to be disassembled later.

+1
Plumbers mait, I just fitted a sink waste and had small leaking issues
Plumbers mait resolved it.

bodge

[Harry Bloomfield, Esq.]

bodge

but a bodge which works..

[Jim GM4DHJ ...]

Post by Harry Bloomfield, Esq.

bodge

but a bodge which works..

shocking

[Lee Nowell]

Hi all

I was going through the various sheets of instructions I had kept for the various bathroom fittings. On the shower tray one at the back was some instructions for fitting the trap (never thought of looking tbh). Anyway the instructions were to put some mastic on the tray then rubber washer then the fitting itself. Then screw it all together.

Hope this helps someone else

Thanks

Lee.

[Roger Hayter]

Post by Harry Bloomfield, Esq.

Post by Lee Nowell
I am installing a new shower tray and the waste it comes with has a very
thin washer that goes on top of the tray and underneath the waste
fitting. Is this enough to seal the top or should I silicone it on to
the tray? Or I guess fit it and silicone around it?

Put some Plumbers Mait around the sealing points, plus long the threads
too, to be sure of no leaks. It's none setting, so comes off easily
where it squeezes out or if it needs to be disassembled later.

If I remember rightly I don't think the washer on top *is* an important
sealing point, as the metal part is open underneath. It just stops
water bypassing the plug, and a slight ooze does not matter. The seal
is to the underneath of the tray, and this is where sealant is best
used.

[Jim GM4DHJ ...]

Post by Roger Hayter

Post by Harry Bloomfield, Esq.

Post by Lee Nowell
I am installing a new shower tray and the waste it comes with has a very
thin washer that goes on top of the tray and underneath the waste
fitting. Is this enough to seal the top or should I silicone it on to
the tray? Or I guess fit it and silicone around it?

Put some Plumbers Mait around the sealing points, plus long the threads
too, to be sure of no leaks. It's none setting, so comes off easily
where it squeezes out or if it needs to be disassembled later.

If I remember rightly I don't think the washer on top *is* an important
sealing point, as the metal part is open underneath. It just stops
water bypassing the plug, and a slight ooze does not matter. The seal
is to the underneath of the tray, and this is where sealant is best
used.

correct

[Roger Hayter]

Post by Jim GM4DHJ ...

Post by Roger Hayter

Post by Harry Bloomfield, Esq.

Post by Lee Nowell
I am installing a new shower tray and the waste it comes with has a very
thin washer that goes on top of the tray and underneath the waste
fitting. Is this enough to seal the top or should I silicone it on to
the tray? Or I guess fit it and silicone around it?

Put some Plumbers Mait around the sealing points, plus long the threads
too, to be sure of no leaks. It's none setting, so comes off easily
where it squeezes out or if it needs to be disassembled later.

If I remember rightly I don't think the washer on top *is* an important
sealing point, as the metal part is open underneath. It just stops
water bypassing the plug, and a slight ooze does not matter. The seal
is to the underneath of the tray, and this is where sealant is best
used.

correct

Except that we're probably thinking about sinks with integral overflows,
and maybe shower trays and baths don't have plugs or integral overflows,
so the seal on top may be more valuable, It still looks messy having
sealant on top, but if you don't then you need to seal the threads of
the back nut as well as the face.

So I withdraw my comment.

[Harry Bloomfield, Esq.]

Post by Roger Hayter
It still looks messy having
sealant on top, but if you don't then you need to seal the threads of
the back nut as well as the face.

Plumbers Mait can just be wiped off.

[T i m]

Post by Roger Hayter

Post by Jim GM4DHJ ...

Post by Roger Hayter

Post by Harry Bloomfield, Esq.

Post by Lee Nowell
I am installing a new shower tray and the waste it comes with has a very
thin washer that goes on top of the tray and underneath the waste
fitting. Is this enough to seal the top or should I silicone it on to
the tray? Or I guess fit it and silicone around it?

Put some Plumbers Mait around the sealing points, plus long the threads
too, to be sure of no leaks. It's none setting, so comes off easily
where it squeezes out or if it needs to be disassembled later.

If I remember rightly I don't think the washer on top *is* an important
sealing point, as the metal part is open underneath. It just stops
water bypassing the plug, and a slight ooze does not matter. The seal
is to the underneath of the tray, and this is where sealant is best
used.

correct

Except that we're probably thinking about sinks with integral overflows,
and maybe shower trays and baths don't have plugs or integral overflows,
so the seal on top may be more valuable, It still looks messy having
sealant on top, but if you don't then you need to seal the threads of
the back nut as well as the face.
So I withdraw my comment.

I think the issue is with single layer fittings (no integral overflow)
the seal *can* be at the top and without the need for any sealant on
the thread.

With a shower where you don't have a built in overflow, even though
you might never use a plug and therefore don't need to seal the tray
as such, water going under the top flange may still leak past the
lower washer / threads but the difference is you *only* need to seal
the top flange in that case.

Anything with an integrated overflow generally means you *will* have
water around the outside of the waste below the primary surface and
therefore the threads and lower nut-to-basin exposed to water, hence
the need to seal both top (water bypassing the plug but not leaking
out of the system) and bottom / threads (leakage from the system).

I must admit I was surprised to learn that you had to seal such things
with sealant (rather than just rubber washer washers) 'these days'.

You might be able to get a straight mechanical seal where the waste
fitting is designed to match the (say) basin where they could have an
expanding seal [1] on a plain (not threaded) tube.

Cheers, T i m

[1] Like the rubber bushing you get in the bolt up BNC connectors and
the like.

[Roger Hayter]

Post by T i m

Post by Roger Hayter

Post by Jim GM4DHJ ...

Post by Roger Hayter

Lee Nowell expressed precisely : > I am installing a new shower tray
and the waste it comes with has a very > thin washer that goes on top
of the tray and underneath the waste > fitting. Is this enough to
seal the top or should I silicone it on to > the tray? Or I guess fit
it and silicone around it?
Put some Plumbers Mait around the sealing points, plus long the
threads too, to be sure of no leaks. It's none setting, so comes off
easily where it squeezes out or if it needs to be disassembled
later.

If I remember rightly I don't think the washer on top *is* an
important sealing point, as the metal part is open underneath. It
just stops water bypassing the plug, and a slight ooze does not
matter. The seal is to the underneath of the tray, and this is where
sealant is best used.

correct

Except that we're probably thinking about sinks with integral overflows,
and maybe shower trays and baths don't have plugs or integral overflows,
so the seal on top may be more valuable, It still looks messy having
sealant on top, but if you don't then you need to seal the threads of
the back nut as well as the face.
So I withdraw my comment.

I think the issue is with single layer fittings (no integral overflow)
the seal *can* be at the top and without the need for any sealant on
the thread.
With a shower where you don't have a built in overflow, even though
you might never use a plug and therefore don't need to seal the tray
as such, water going under the top flange may still leak past the
lower washer / threads but the difference is you *only* need to seal
the top flange in that case.
Anything with an integrated overflow generally means you *will* have
water around the outside of the waste below the primary surface and
therefore the threads and lower nut-to-basin exposed to water, hence
the need to seal both top (water bypassing the plug but not leaking
out of the system) and bottom / threads (leakage from the system).
I must admit I was surprised to learn that you had to seal such things
with sealant (rather than just rubber washer washers) 'these days'.
You might be able to get a straight mechanical seal where the waste
fitting is designed to match the (say) basin where they could have an
expanding seal [1] on a plain (not threaded) tube.
Cheers, T i m
[1] Like the rubber bushing you get in the bolt up BNC connectors and
the like.

Where I need a sealant for *plastic* threads, or plastic to metal, I've
found Fernox LS-X is much better than PTFE tape, which tends to extrude
itself from plastic threads.

I would be interested in what people use to seal the waste to the top of
such things as shower trays. Plumber's mait can be gradually washed out
if the edge of the waste is cleaned too fastidiously, and can look
smeary if it isn't.

[T i m]

On Tue, 27 Aug 2019 16:20:17 +0100, ***@hayter.org (Roger Hayter)
wrote:

<snip>

Post by Roger Hayter

Post by T i m
[1] Like the rubber bushing you get in the bolt up BNC connectors and
the like.

Where I need a sealant for *plastic* threads, or plastic to metal, I've
found Fernox LS-X is much better than PTFE tape, which tends to extrude
itself from plastic threads.

I'll check that out.

Post by Roger Hayter
I would be interested in what people use to seal the waste to the top of
such things as shower trays. Plumber's mait can be gradually washed out
if the edge of the waste is cleaned too fastidiously, and can look
smeary if it isn't.

I think I've generally used clear silicone, masking the area prior to
application helping give a clean result (tape down first, cut round
with a scalpel, remove fitting and inner tape, seal, fit and trim /
peel outer tape when it's cured slightly).

If the hole is recessed enough and the outer diameter of the flange
pretty close, I might just silicone up to the hole / flange.

Cheers, T i m

[Harry Bloomfield, Esq.]

Post by Roger Hayter
I would be interested in what people use to seal the waste to the top of
such things as shower trays. Plumber's mait can be gradually washed out
if the edge of the waste is cleaned too fastidiously, and can look
smeary if it isn't.

It only washes out from where it is visible, it doesn't wash out from
under flanges where it really matters.

[newshound]

Post by Roger Hayter

Post by Jim GM4DHJ ...

Post by Roger Hayter

Post by Harry Bloomfield, Esq.

Post by Lee Nowell
I am installing a new shower tray and the waste it comes with has a very
thin washer that goes on top of the tray and underneath the waste
fitting. Is this enough to seal the top or should I silicone it on to
the tray? Or I guess fit it and silicone around it?

Put some Plumbers Mait around the sealing points, plus long the threads
too, to be sure of no leaks. It's none setting, so comes off easily
where it squeezes out or if it needs to be disassembled later.

If I remember rightly I don't think the washer on top *is* an important
sealing point, as the metal part is open underneath. It just stops
water bypassing the plug, and a slight ooze does not matter. The seal
is to the underneath of the tray, and this is where sealant is best
used.

correct

Except that we're probably thinking about sinks with integral overflows,
and maybe shower trays and baths don't have plugs or integral overflows,
so the seal on top may be more valuable, It still looks messy having
sealant on top, but if you don't then you need to seal the threads of
the back nut as well as the face.
So I withdraw my comment.

As you say, without an overflow *I* reckon the rubber washer is the
primary seal. I had a shower develop a leak after everything was boxed
up because the plastic nut underneath evidently jumped a thread, leaving
the metal part slightly loose. Not wanting to hack into the ceiling
underneath, I dried everything out as well as I could and used warmed-up
araldite to re-seal the metal to the tray. This has worked fine for 20
years or so.

Plumbers mait is OK on the traditional locations but personally I find
the somewhat thinner boss white better in many places.