On Sunday afternoon, just as the shops were closing, we discovered a wet patch on the ceiling directly beneath the bath. I removed the side panel and saw that the waste fitting was smeared with plumber's mait, which was weeping when the bath drained.
I did a google search and found that people don't seem to rate plumber's mait. The impression I got was that it always starts to leak after a few years. What does the group think? Is it any use these days?
I tried to remove the plumber's mait. Is it just a case of picking at it? I read on the 'web to use another piece of plumber's mait but I didn't have great success with that and found scraping it worked better.
The fitting was a threaded, slotted, chrome plated brass "plug hole" (does it have a proper name?). Underneath the bath, this was surrounded by a plastic banjo fitting that connected the overflow.
Again on the web, I found various forums, including professional plumbers in the SF forum, complaining about bath wastes. One problem seems to be that the hole in the bath is bigger than the fitting, allowing it to move and leak. Why do bath manufacturers do this?
The banjo fitting had some nylon washers. Something like this: http://www.toolstation.com/shop/Plumbing/Washers+Fixings/Bath+Washer+112/d20/sd2703/p38971
Why are these made from nylon? I would have thought something softer, like rubber, would be better as it would deform to the surface it is on. Isn't the nylon a bit too firm?
The banjo fitting ruins it. It is the weak point of the design. Why don't they make the overflow integral to the bath, like they do for basins? That would solve the problem?
Do you even need an overflow? Kitchen sinks always used to have overflows but now I think about it, fewer seem to have them these days. The same for shower trays too (and toilet cisterns). If these can live without overflows, why not baths?
I found an unopened but old tube of sanitary sealant in the garage. I tried to fix the banjo with that. I left the silicone hours to cure but it still leaked. Possibly due to limited access to the far side, I missed bit. But I think everything rotated when I screwed on the trap, breaking the seal.
So then I had to try and scrape it all off! I can't work out which I hate most: plumber's mait or silicone. Both are nasty and sticky to apply. The silicone is not sticky to remove, which may be an advantage, but it still requires a lot of scraping. I think they are both as bad as each other.
It seems to me that to use either is a bodge. Why can't they make fittings that do not leak? After all, I don't silicone around my 15mm compression joints!
I decided to throw it in the bin and buy a new one the next day.
On Monday morning I went to Tool station and bought one of each of these: http://www.toolstation.com/shop/Plumbing/Traps+Waste/Bath+WasteOverflow+Centre+Pin+1+12/d20/sd2907/p59080 http://www.toolstation.com/shop/Plumbing/Traps+Waste/Chained+Bath+Waste+with+Overflow+1+12/d20/sd2907/p90876
They look more-or-less the same in the catalogue but are from different manufacturers.
I tried the wirquin one first. It is without doubt, the worst product ever. Never, ever, ever buy it.
Wirquin also sell one with a trap included. It is reviewed on the B&Q web site: http://www.diy.com/nav/fix/plumbing/plumbing-supplies/waste___overflows/-specificproducttype-traps/Wirquin-Chained-Bath-Waste-and-Trap-11478476
There are Iwo reviews, both score it one out of five:
"DO NOT BUY THIS PRODUCT This has to be one of the worst DIY buys ever. The screw that attaches the plug hole is far too long and punctures the overflow pipe, the trap leaks like a sieve, the only way we could stop it leaking was to silicone it shut! The plug chain is held to the overflow with a flimsy split ring and the chain itself has started to rust after 2 baths! The overall feel of this kit is cheap and nasty but it isnt that cheap either! If I could give it a no star review, I would."
"Poor: Trap is too shallow and catches on bottom of bath. The quality of the plastic and metal is very poor"
I agree with both of these. The overflow grid screws into a plastic part on the other side of the bath. The screw supplied is far too long and penetrates the plastic and pokes out the other side. What is the point of that?
The actual overflow pipe is similar to flexible conduit. I realise all manufacturers use this. I suppose it is flexible but I would have thought the ribs are a great place for crud to accumulate and block the pipe. Perhaps they get away with this because the overflow is not used often/at all?
However, in this product the wall of the flexible pipe is paper thin and was easily damaged.
There does not seem to be any standardisation with the overflow pipes, so you cannot mix and match ones from different makes as the diameters are all slightly different.
This fitting has a metal grid that fits in the plug hole and this too screws into a plastic part under the bath. I am not so keen on these. I prefer the brass ones held in place by a nut. This is because once over tightened the screw in one of these and it broke the plastic part, causing a leak!
However, these have the advantage that the banjo is not a separate part prone to leaking. that said, this leaked from the join with the overflow but this was probably because the pipe was so thin it deformed, allowing water to pass.
If you are fussy about appearance: the screw for the overflow is pozi but the bolt in the plughole is slotted. Why can't they match?
I took the wirquin part off and threw that way too!
I reluctantly fitted the McAlpine one, expecting more of the same but it was third time lucky. Very similar in design to the wirquin but the overflow pipe is only retained by friction. However it is a very secure fit, so I am quite confident about it. The flexible pipe is much thicker and stronger, so no worries there either.
Sadly the overflow grille is plastic, which I don't think is as nice as metal but and here's the important bit: with the rubber (not nylon!) washer provided, it formed a water tight seal under the bath with no need for silicone or plumber's mait. This shows it can be done!
Although I would have preferred an all metal fitting for cosmetic reasons, function is more important than looks, so I am very happy with this. What a shame it took three goes to find a fitting that worked.
I wonder why they don't make more fittings from metal. I'm sure it must be more reliable than plastic. I was going to order something like this but couldn't wait for it to arrive in the post: http://www.ebay.co.uk/itm/High-Quallity-Brass-and-Chrome-Barhroom-Bath-Overflow-POP-UP-WASTE-/261036984530
Why not use 22mm copper for the overflow?