sealing villa board

[wattsy]

I am currently renovating our bathroom and are seeking advice on sealing villa board sheeting in the shower area.I intend to apply a waterproof membrane to the floor and partially up the walls.the wall tiles will be floor to ceiling.Should i seal the walls outside of the waterproofed area and if so with what product?I guess any product would have to be compatible with wall tile adhesive.I am feeling some pressure from SWMBO as the novelty of a temporary outside shower is wearing of fast.Any advice appreciated.

Wattsy

[SilentButDeadly]

The board doesn't need to be sealed if outside the membrane area.

However, make sure you aren't stingy about the coverage of your water proof membrane - all floor and some distance up the walls is good but your entire shower cubicle area should be sealed floor to ceiling out to 500mm past either side of the shower...

[wattsy]

The shower area is an enclosed area 1.6m by1.3m with a ceiling mounted rose.would you recommend using the same sealer on the walls as used on the floor?

[SilentButDeadly]

Seal the lot - floor and walls plus another 500mm past the entry. Use the same sealer.

[OBBob]

You can get a davco sealer for the FC sheet that just locks down any dust etc. prior to sticking on the tiles. It is a milky like substance and only take 20 minutes or so to dry. Can be worth it if you have dirtied up the board a bit walking on it or there has been much dust around.

The membrane should be one type on the floor and walls with bonding tape etc. at any joins. You should take the membrane past the height of the rose or to the ceiling if that's where it's fitted.

[silentC]

Let's be clear about waterproofing vs. sealing.

For waterproofing, what you should do is apply your waterproofing membrane to the entire floor and 100mm (I think) up the wall all around the room, and to the height of your splashback behind the bath (if any). The entire shower enclosure should also be waterproofed at least to the height of the rose (in your case, the ceiling). The floor to wall joins must also be waterproofed, using tapes and/or sealants as required and recommended by the membrane supplier. What you are doing is forming a waterproof 'tray' that covers the whole bathroom floor.

Sealing is only required if you are going to paint. You can put the tiles straight on to the villaboard without any sealer.

[wattsy]

Thanks all for advice

[stemail23]

...also my tiler recommended that I correctly prime the villaboard before applying the waterproofing membrane, otherwise the membrane can peel off the villaboard. If you consider that the tiles are actually adhered to the membrane, then the importance of not having this membrane peel off the villaboard becomes apparent.

Steven

[silentC]

Yes you usually need to apply a primer before the membrane, that will be detailed in the directions.

[arms]

Originally Posted by stemail23

...also my tiler recommended that I correctly prime the villaboard before applying the waterproofing membrane, otherwise the membrane can peel off the villaboard. If you consider that the tiles are actually adhered to the membrane, then the importance of not having this membrane peel off the villaboard becomes apparent.

Steven

another thing to consider is the adhesiveness of the membrane with tile adhesive ,nowadays tile adhesive manufacturers do not guarantee their product for fastness unless you specifically use the waterproofing brand they specify

[stemail23]

Originally Posted by silentC

Yes you usually need to apply a primer before the membrane, that will be detailed in the directions.

... the membrane that I used didn't mention priming on the instructions, which is why I brought it up

The other thing that I don't think anybody has mentioned is to make sure you use some sort of bond breaker at the floor/wall angle. This prevents the waterproof membrane from splitting if there is any movement between floor and wall over time.