shower tiling/waterproofing nightmare

[parso123]

We are currently renovating our ensuite. Long story short, we had a waterproofer come in and do waterproofing (over villa board)... fine. Tile guy comes and puts up tiles... fine, that is until I happen to check the adhesive that he's used (Davco TP4000 power mastic) and it specifically says "should not be used with waterproofing membranes."

Then I go online and find a data sheet for the type of membrane used (Aquathane XR - a latex membrane), and it specifically says not to use premixed mastic type adhesives, which is exactly what he used.

So my questions are - what is the problem going to be? The tiles perhaps falling off or the waterproofing failing, or both? Who's at fault? Waterproofer never mentioned type of adhesive. Tiler claims store where he bought it said it would be ok. Shouldn't he have know to check the type of membrane?

And finally, what should we do? (Tiles have not been grouted yet). Pull them off, and possibly have to replace the villaboard and waterproofing? Start drinking heavily and pretend it never happened? HELP!!!

[Rossluck]

We are currently renovating our ensuite. Long story short, we had a waterproofer come in and do waterproofing (over villa board)... fine. Tile guy comes and puts up tiles... fine, that is until I happen to check the adhesive that he's used (Davco TP4000 power mastic) and it specifically says "should not be used with waterproofing membranes."

Then I go online and find a data sheet for the type of membrane used (Aquathane XR - a latex membrane), and it specifically says not to use premixed mastic type adhesives, which is exactly what he used.

So my questions are - what is the problem going to be? The tiles perhaps falling off or the waterproofing failing, or both? Who's at fault? Waterproofer never mentioned type of adhesive. Tiler claims store where he bought it said it would be ok. Shouldn't he have know to check the type of membrane?

And finally, what should we do? (Tiles have not been grouted yet). Pull them off, and possibly have to replace the villaboard and waterproofing? Start drinking heavily and pretend it never happened? HELP!!!

Gerday Parso, I's be blaming the tiling place that sold you the adheseive. I mean, using membrane waterproofing systems is standard behaviour. He or she shouldn't have sold you an adhesive that won't work with membranes.

That said, what I would so is use the most waterproof grout I can find and take a chance. Good luck mate, it should be OK.

[mic-d]

Mastic is used as standard practice in wet area tiling but because it sets by drying rather than a chemical set that a cement-based adhesive has, It takes longer to dry and set on the w/p membrane - this is why the warning. Just make sure it has set before grouting so that the tiles don't move. I would also put a sureseal treatment on the grout too. Don't worry, it will be fine.
A few years ago I put some mastic on the back of a tile and let it dry out for a few days, then I soaked it in water to see if it softened but it did not. Think of it like acrylic paint - once it's dry you don't worry that it will wash off every time it rains!
Cheers
Michael

[parso123]

Thanks so much for responding. We feel a bit better now. I guess my fear was that there was some sort of chemical incompatibility between the two... so we really don't need to panic?? I will definitely seal it as well as using a grout with increased water resistance.

[silentC]

I would make the tiler re-do it. He should know better. But then they never read the directions on the tin, do they?

I would contact the manufacturer of the membrane and find out why they say not to use mastic adhesives. There has to be a reason, a company doesn't limit the application of it's products like that without a reason. Maybe they've had a few failures, maybe you'll be lucky.

Was the whole wall waterproofed, or just the corners and joins?

If it was me, the tiler would be coming back. At his cost.

[bitingmidge]

I agree entirely with Silent.

You may have no problem. Mic-d may be correct.

I've seen waterproof membrane fail because of incompatible adhesive, and I've seen adhesive fail as well.

Often it's not spectacular, just a leak turning up in the hallway, or three rooms away, which you eventually track back to a couple of tiles or a crack in the shower corner where the tile adhesive has stayed green for weeks, and reacted with the waterproofing. Maybe only one or two tiles will go drummy, or even just sit there, held in by the grout.

In any case, you won't have what you paid for.

From memory, the solvents in the pre-mix break down the latex, get a rubber glove and rub it with some acetone to get a feel for what happens... it doesn't entirely dissolve, but you'll get "wet" fingers anyway.

It's a question of when you want the grief really. Now, when you can share it with someone, or in a year or three (or even five) when it's all yours.

Alternatively, you could strike a deal and take your chances, maybe don't pay the guy for his labour or something.

Come to think of it, that'd "save" 50%, hasn't there been a thread about this sort of thing recently?

P

[frog's wife]

Just a quick note re the waterproofing membrane. I've seen a number of membranes fail because of the use of BLEACH! Yup, "ExitMould" , "whiteking" or any ammonia based bleaches can cause some waterproofing to fail. I know that Davco waterproofing was one of the brands that failed. Check with the manufacturer about using bleach as a cleaning product in your bathroom.

Sonja

[parso123]

Hi, thanks for all your responses. We have spoken to the mastic manufacturer, the membrane people as well as some tile people.... the answer from all of them was the same as mic-d... basically that the only concern is with the drying time before grouting and it will be at least 10 days between tiling and grouting in our case.

(Also the mastic was only used on the walls, not shower base). Thanks again for your thoughts.

[silentC]

Hmm, not that I'm sceptical - but if that's the case, why don't they say "If you use a premixed adhesive (mastic), sufficient drying time must be allowed before grouting" rather than "Premixed adhesives (mastik’s) are not suitable for tiling over Aquathane-XR and should not be used."

Anyway, good luck with it..

[bitingmidge]

I'm sorry, but "speaking" won't help you in two years' time.

Get written confirmation from both, then you and your tiler can rest easy.

The tiler should be popping out of his breeches to help!

I'm glad it's easily solved.

cheers,

P

[mic-d]

the answer from all of them was the same as mic-d...

Thankju, I take a moment for myself.. bow down, bow down.......


That's enough, I feel jure love.

Cheers
Michael

[journeyman Mick]

Definitely what Biting Midge said, get it in writing! You may even find that when you ask them for confirmation in writing that there won't be any issues that they'll change their mind and decide they can't give you that assurance.

Mick

[zacnelson]

I recently finished tiling a new bathroom I'm building. I used Davco K10 for the waterproofing membrane (it's green coloured) and began using Davco powder mastic for my tiling adhesive, it was recommended by the tiling place. Anyway, I soon grew very tired of mixing up the powder adhesive all the time, I ended up wasting too much of it as well because it is hard to estimate quantities perfectly. Most of all, when I was sticking the tiles to the wall, they slid down all the time, it was useless.

So I went and bought a 20kg tub of Ardex abamastic for the wall tiles (I continued to do the floor tiles with the old stuff). The warning on the abamastic said only that if used over waterproofing membranes, the drying time was increased. That certainly wasn't enough to put me off!

Anyway, it worked absolutely beautifully, so much more convenient than constantly mixing up new batches of adhesive, and most importantly, the tiles weren't slipping down the wall anymore!

It is now a week later, and the wall tiles are rock solid. Most of them were stuck to the shower walls, which were fully covered in the Davco K10 membrane. The rest were stuck straight onto Villaboard. I can not discern any difference at all; the tiles on both surfaces seem as if they would be impossible to remove. And from what I can see on the perimeter of the tiled area, where I can visually inspect the surface where the glue is hardened onto the membrane, there is no damage or alteration to the membrane as a result of the adhesive.

[silentC]

And yet "Premixed adhesives (mastik’s) are not suitable for tiling over Aquathane-XR and should not be used."

Someone had a reason for writing that on the instruction sheet. Maybe whoever it was should be hunted down and fired, as according to all these expert witnesses, it's bollocks

[bitingmidge]

Silent,

You missed the line before the one you quoted in the Aquathene-XR data sheet:

Do not use solvent based adhesives as failure of membrane and
adhesive will occur.

The AbaMastic Data Sheet says:

Do not use solvent based adhesives as failure of membrane and
adhesive will occur.

The Davco waterproof membrane is a waterbased polyeurethene and is "fully tested for use under Davco cement based tile adhesives".

I suspect that the Davco membrane will be OK if it was allowed to cure properly first, but I wouldn't like to be making a warranty claim for any failures!

If a failure occurred, and a claim was lodged with the Building Services Authority in Qld, the subcontractor/builder would have no case!

Eight times out of ten there may be no problem, I reckon that's two of 'em above!

Cheers,

P