Thread: Waterproofing a ensuite

I used Emer-Clad which is a "One component liquid, elastomeric waterproofing membrane". It's really pretty easy to use just paint on a couple of coats let it dry and you've got a flexible membrane about a mm or two thick. Sticks to a timber floor too.

So I put down an emerclad membrane then a mortar bed over the top so that I'd get a good fall to floor waste, then tiled over the top of that. Been using it for about four years now without drama.

I can't help you with the shower problem 'cause I went with a one piece pre-made shower base. They work fine without leaks if you install them properly (set into the wall slightly).

Davco and ABA etc all make water proofing systems available from tiling places. If you are doing just the one ensuite, i would personally get a waterproofer in to do it, especially on chipboard sub base - it needs to be really flexible and will get a lot of use.

I have diy'd the back bathroom laundry but used a professional for the ensuite - you are looking at at least $200 for a bucket of waterproofer - (might get away with a 10litre) plus fibre, primer etc - while a professional might charge $300 and you get a guarantee these days when installed by a certified installer - given how many bathrooms leak - I reckon thats a bargain personally.

If you put more waterproofing in the hob, make sure the tile glue is compatible with the waterproofer - not all are.

If you do decide to go with a professional wet-seal installer, just remember that the guarantee only covers their work. Someone else (that is, you..!) has to pay for the tiles to be chipped off the floor, any damage to the subfloor or walls rectified, and new tiles put down.

If its been a few years since your tiles were laid, you also get the excitement of finding matching tiles (good luck) or the fun of paying for new tiles across the entire bathroom if you can't find an acceptable match.

Personally, if given the chance, I would do my own because I tend to take a bit of time and do dumb things like vacuum all the dust and junk off the floor. I also tend to read and follow the instructions!

If the off the shelf waterproofing systems look too pricey, look at buying some West System Epoxy and fibreglass mat. Just use a bond breaker over any joints in the subfloor. If it's good enough to keep boats waterproof, a shower will be a doddle! Mind you, you'd better make sure you buy plenty of West System Epoxy, as its better to have a little left over than run out! <img>

Here's my story with waterproofing - I've had problems with my ensuite for a few years.

About a year after we moved in (new house), we noticed that the grout between the tiles was starting to discolour badly. The builder inspected it and said that it couldn't possibly be water leakage as the bathroom was sealed.

By another year later, the tiles were starting to come off the floor, and there was water damage all across the subfloor. This time the builder accepts that there might be a problem, and his tiler comes back to take out the shower recess and take up all the floor tiles and clean it all up.

The wet seal guy comes back and re-does the waterproofing. The builder can't find the $60 psm tiles we had originally, and substitutes $25 psm tiles. The tiler re-tiles. The shower screen gets refitted.

The first time we use the shower after all this, water ponds on the floor.

Cause of the leak - the mortar bed that the shower floor tiles are on is built up to the height of the aluminium step around the shower. This puts the tile adhesive and the tiles above the height of the supposed water barrier. Result is that water soaks through the grout, collects in the grooves in the tile adhesive, and runs out at the edge of the shower.

Exactly the same problem as before, only now the water ponds on top of the tiles instead of under them!! Oh well, time to call the builder again.

Thanks, I'll do it myself next time!

Hello John,
If doing it yourself look into a product called liqiud flash. Its available at most builders suppliers, expensive, easy enough to apply, allows multiple coats to form the membrane, flexible & WORKS. IMO a worthwhile product & widely used in this area of highly reactive soils, coped with movement as well as anything I've heard of. Happy New Year, Bill

I thought it was now COMPULUSORY to have a properly qualified tradesman do waterproofing and that it must be council inspected ????

Eek! how much is this going to cost me?

Yep, I do have to have the waterproofing inspected by the council, but in my area it doesnt necessarily have to be done by a waterproofer only needs to comply with the standard.
Which I`m hoping to exceed the standard.

It seems amazing that the old bathroom in the old part of the house when I tiled it a few years ago, I pulled the cement sheets off the old shower to check for leaks and it was as dry as.
And it has what looks like a couple of pieces of gal flashing up the corners and around the base, then the sheets screwed on amazing after 50 years,
So maybe I might be as lucky )

"I thought it was now COMPULUSORY to have a properly qualified tradesman do waterproofing and that it must be council inspected ????"

Anything that is exempt development doesnt require consent or inspection, Kitchen, bathroom, relining walls, fixture and fittings et etc are exempt developments in NSW, as is installing air cons > 3m from boundary. If you put in a DA with a proposed reno and you include bathrooms and kitchens in your changes then you come under the same controls as if it was a brand new home - you also get to pay their fees and insurance on that work - good reason to omit anything on plans that doesnt need an approval I 'd say.

Of course not all states and councils are the same - they vary in the level of insanity.

Ok, i also am diy the ensuite, after jackhammering the tiles off i have re rendered (brick walls) ....im installing the preformed base and hopefully those prefab walls but do i have to put on villa board or similar to hang the tiles/walls off? and what then gets waterproofed?..the render or the boards?

Well after much thought I decided to put down a hob, using bricks then render it and leave it a couple of days before waterproofing.

I did use some Crommelin Cement Modifier in the mix, It should stenghten, waterproof, and hold together the mortar mix.

I have Crommelin Shower waterproofing membrane and bond breaker bandage to do the waterproofing with.

Looking back now I maybe would of used a preformed base, but that that will have to be in the main bathroom when I get around to that. It might of made this part a bit easier but I did really want to pull the walls back off to fit the base.

rank amatuer
with those complete shower unit (base ,Screen, walls,) they are waterproof and meet the standard.
with the villa board do you mean in the shower or the rest of the room ?
to fit your tiles to ?

Hi all
Just a up date on the progress of the ensuite. Well after a bit of mucking around and chasing up a shower screen and working out what, how and where, with the hob, waterproofing and bond breaker.

And a great deal of asking questions on here and anyone that I could get advice from, to which I thank you all.

I had a council inspection today for the waterproofing and it passed with flying colours. )

Although the council inspector spent all of 15 secs having a look at it. Just a quick glance and off he went.

For a run down on what I did / used. noting that the floor is particle board and the walls are villa board. with a 75 x 50 pvc angle around the floor and up the corners under the villa board

• Made the hob out of bricks
• Rendered it
• Used cement mortifier in the mortar mix to hold it together and waterproof the mortar in the hob.
• waterproofed the floor walls etc with Cromellin waterproofing membrane
• Used bond breaker bandage on all the corners i.e around/in hob corners, floor etc.
• 2 coats over the walls and floor with the membrane
• 3 coats in the shower area.

I still now need to make the fall in the shower and on the floor, but I`m quiet happy that it past the inspection not knowing what they might pick up on.

Cheers )
John