Hello All,

I feel kinda dumb asking this question, but better safe that sorry.I am in the process of tanking a shower cubicle, the walls have been skimmed and aloud to dry over 2 weeks and are clean, the shower tray in already installed so tanking is next.

I had a search around but could not find an answer, i am about to use the PCI Lastogum X tanking kit, i am using the tap provided for corner joint but my question is do i need to use the this tape where the wall meets the top of the show tray? the tape is 100mm wide, 60mm of that is the waterproof membrane.

My worry is if i apply the tape to the joint between the wall and the top of the tray is that it will protrude to much out under the tile when it is applied.
This is the area i am tanking,



Does this make sense? What do other people do here.

Thanks in advance

Robbie

Silicon seal the tray to the wall then when cured tank the walls and tape all corners and joints and the bottom of the tray overlapping about 6mm. The tile will cover this.

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Hi Mike,

Thanks for your help, i should point out the tape that comes with the PCI kit is non-adhesive it only a sealing tape and needs the PCI lastogum applied over it, this is where my confusion is.

Thanks Again

I'm not familiar with that kit or tape but none of the tape I've used is self adhesive. I just paint the tape area with tanking then apply the tape then paint over again. Then a second coat of tanking a couple of hours later

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Hi mate and welcome to the forum. I'm like mike with similar idea. What I do is silicon the tray to plaster joint and allow to set then put masking tape around the shower tray leaving the thickness of a tile showing, then put paper or plastic masked to the tray to keep clean. Prime the walls if your tanking kit requires you to. Paint the corners with the tanking, put on the tape and paint over to seal. If the tape has an edge to it that is not waterproofing then cut it off. Paint the bottom corner joint with tanking and just onto the masking tape, put the tape on so your cut edge is level with the masking tape edge (you should see the edge under the tanking youv'e just painted on) and paint over to seal, then paint all the walls as required. When you have tiled and grouted, carefully cut along where the tiles meet the tray, remove masking and excess tanking and silicon to give you a lovely sealed tray joint. Hope this helps...good luck.

I use the lastogum kit a lot, and it can be done in two ways, As PT has mentioned above, just cut off the "fabric" part of the tape on one side for the tray.
This will provide a seal of 8-12mm wide between wall and tray. Not enough at this critical point in my opinion.Should the tray sink, say 5mm, this will put a lot of strain on this point.

What I prefer to do,(although this needs to be done before the tray is fitted) is to tank the walls first, continue the tanking paste down the walls at least 50mm past the top of the tray. Then re/fit the tray, leaving a small gap between wall and tray. Fill this gap with silicone to the top of tray and smooth off. You will find that the silicone will stick very well to the tanking paste, much better than to a dusty skimmed wall. You now have a 50mm+ vertical seal, which is the direction the tray will most likely move. You don't realise how strong this is until you have to remove one in a few years time.
If you are lucky and good with a float you can do this with the tray fitted, as long as there is a reasonable gap for the float to fit down

A few points to note
Remember to use the supplied primer g first
A lot of trays come with a protective clear plastic film, make sure to remove this where you are going to silicone to

Andrew

Listen to the gents above. The joint between the tray and the wall is one of the most important places to make water tight

Shower Tanking picture.jpgLike this

You guys are awesome, i'm gonna get cracking on this today, thanks all for your help.