Replace Preformed Shower Base

Do I have to apply a painted membrane over the villa board before tiling? Yes
Do I also have to waterproof the corners between the wall and floor Yes - but doing the whole floor isn't much extra cost/effort.

See also: HIA - Waterproofing requirements for wet areas (NAT)

http://www.jameshardie.com.au/home/a...uction0906.pdf

Originally Posted by cozzaa

Hi,
Im pretty new to using forums - so here goes.
I have removed all the tiled floor and shower tiles. The shower walls were originally tiled straight over normal wall board.
My plan is to lay fibre cement sheet on floors and rebed the showerbase over the sheet.
Once the shower base is in apply villa board to the walls for tiling.

Having read a few threads I am confused over waterproofing.
Do I have to apply a painted membrane over the villa board before tiling?
Do I also have to waterproof the corners between the wall and floor or the whole floor?
All advice appreciated!

Having two wall sheets one on the other is no advantage, as you plan to install new Villaboard you would be far better off removing the old sheet, this will also help to remove any high or low spots in the old sheet and avoid the extra thickness that will need hiding. Not to metion a good chance to inspect the condition of the timber and plumbing.

The above will also remove possible issues with the Villaboard not going all the way to the floor.

If the existing floor is timber you only need tile underlay, much cheaper and fit for purpose.

Waterproofing requirements:
The rear corner/s must be flashed to a minimum of 1.80 metres from the floor.

The bottom wall to floor joints must also be flashed, they are a minimum of around 80 mm high and wide, but must be above the the highest overflow point; that means if you had a 100 mm hob the flashing must be higher, this ensures water runs out of the shower and hopefully down a floor waste, rather building up onto a wall section that has not been waterproofed.

Taps should be sealed before tiling.

The floor of the shower should be fully waterproofed, this can be done before or after the cement base for fall is installed.

Hope this helps.

Originally Posted by Oldsaltoz
Having two wall sheets one on the other is no advantage,
I have removed all old sheeting and am going to use 9mm villa board so I don''t have to replace the entire wall width.I wasn't planning to tile more than 300 mm past the shower screen.

The above will also remove possible issues with the Villaboard not going all the way to the floor.

If the existing floor is timber you only need tile underlay, much cheaper and fit for purpose. I have yellow tongue flooring and will be laying tile underlay.

Waterproofing requirements:
The rear corner/s must be flashed to a minimum of 1.80 metres from the floor.
On the tile underlay I was planning to bed the base in cement. I was going to paint a membrane over the underlay before bedding in the base.
I was then going to put the angle flash to the inside corner of the shower before sheeting the wall with villa board. Is there any more I would have to do in the shower before tiling? I understand I need a silicone bead where the villaboard sits into the base.

No, You should put the Villaboard on right down to the floor, then nail the tile underlay, then waterproof the base of the shower fully including down into the waste pipe.
Also flash up the walls to a point 80 mm above your bedding line, and flash the corner/s from the floor to 1.80 metres up the wall/s. You should get a better bond on the bedding than you will on a membrane.

Taps should be sealed before tiling. Understood.

Hope this helps.

My preference for waterproofing is fibreglass using a modified resin that cures with a lot more flexibility than normal GRP.

This is then coated with a thin layer of epoxy resin, this is well known for it's long term ability as a chemical barrier.

The total lay-up is around a 1 mm and dead flat not enough to cause an armature any problems.

This system was started about 30 years ago and very few if any have failed, mind you it's not the cheapest out there but you get what you pay for don't you.

Many new materials are also being developed that will reduce the solvent content used and attain a 'Green' rating.