Another shower tray leak

[jackg]

I re did this shower tray in August last year and I am getting slow drips at the tray corners where the tray comes out from the wall.

As you can see it has upstand and I tile onto the tray leaving a gap of 2-3mm. Initially I grouted this joint but then removed as much grout as possible and used silicone. But the grout removal was bound not be to 100%.

I sealed the enclosure frame (the extrusion which screws to the wall) on both sides but the enclosure only on the outside as per Roman's (manufacturer's) advice.

http://img16.imageshack.us/img16/1017/p1000410r.jpg

http://img97.imageshack.us/img97/2679/p1000409yn.jpg

I can either:
1. Add more silicone to the bead already there, but will it form a good seal?
2. Remove tile and silicone and redo and try to increase the gap between the tiles and the tray to 4mm and then add silicone to seal.

I have seen classi seal which goes on the outer face of the tray and seals with the wall before tiling over it but this maybe for trays with no upstand?

What is the best way to remove old silicone, I tried Geocell Silicone remover which was ok and also blunt screwdriver etc?

Thanks for advice.

[Sir Ramic]

Do you know exactly where the leak is ? Its not too hard to find by directing the shower spray in different areas and then assess the situation.

[Stewart]

I would hazard a guess that the wall posts for the shower screen weren't bedded Into silicone at the base and is one of the most common places for a leaking shower.....

[jackg]

The water leaks from the joint between the outside of the tray upstand and the tile round it at the top of the upstand, on both corners.

When I applied the silicone first of all I did notapply silicone to the area behind the enclosure frame but last week I applied more silicone to that area to try to seal it, but the leak was still there.

The enclosure and frame has been removed on both sides.

I have just tried the shower spray on the joint between the tray and the tiles and there was no apparent leak when spraying water to the joint, until I got to the edge of the tray then the water sprayed over so it was hard to tell, but no obvious leaks.

[jackg]

I would hazard a guess that the wall posts for the shower screen weren't bedded Into silicone at the base and is one of the most common places for a leaking shower.....

Seems about right, I try again in that area.

[whitebeam]

Try using one of the polymer sealants, they set wheres theres moisture.

[jackg]

Just another little problem I noticed.

The tray is out of level by 6mm over the length of each side (900mm x 750mm) and the water would drift to the corners which leak.

So at worst that incline is 750/6= 1 in 125.
The incline on a flat roof to allow water to drain is 1" in 5' or 1 in 60 so this is half that.

I recall when I installed the tray that there was a slight tilt so I packed more cement under the drain corner or corner that is outermost which then caused it to be not level.

[paul flight]

hi jack, when silicon is applied it should only be seal on the outer parts of the encloser . if you seal inside as well it does no allow the water that gets traped in the chanels to escape back into the tray. the frame will fill with water and then fined is way out at the lowest point!! this may be the problem??

[jackg]

hi jack, when silicon is applied it should only be seal on the outer parts of the enclosure . if you seal inside as well it does no allow the water that gets trapped in the channels to escape back into the tray. the frame will fill with water and then fined is way out at the lowest point!! this may be the problem??

Good point, thanks.

Only the frame was sealed on both sides with the wall and not on the tray, so should not be a problem.

[jackg]

To update.
Water is behind the sealant between the tray and the bottom line of tiles.
I used Dow Corning 785 which is polymer sealant as suggested above?

So I think I would be better to remove the bottom layer of tiles and redo them and to clean all surfaces before applying sealant.

Initially I sealed suing the Microban grout after tiling which did not seal.

Then I removed as much of that as I could without removing the tiles and resealed with the Dow Corning, so there is residue of the grout in the joint.

Unless I can use a better sealant?

Any opinions please.

[jindru]

hi i have found in re sealing shower or bath lips that you have to be very pedantic about cleaning and preparing.remove as much sealant as possible mechanically.ie feincut or flexiblade.then use a good silicon remover giving it enough time to soften up.repeat mechinical removal.remove residue with nylon scourer wash down to clean.use a hairdryer/hot gun to carefully dry off gap.gap must be bone dry to ensure good silicon adhesion.reseal with quality sanitory silicon.its slow but if you take your time itll work.good luck.

[jackg]

The leak was on the connection between the outlet pipe of the valve and the connector which allows the hose to screw onto it. An olive not replaced.

I have removed several tiles to get to this, the ones with damp behind them came off easily whereas the dry areas were tricky and puller away some of the backer board.

I am not sure whether I can fill the hole in the backing board with adhesive and sand the adhesive off and re use the backing board or whether the backing board needs replacing?

As the pic shows

http://img35.imageshack.us/img35/8026/p1000413z.jpg