# Forum Home Renovation Waterproofing  Compatibility Problem - Gripset38 Membrane and ASA Conflex Tile Adhesive.

## Billy22Bob

I did Gripset38 membrane (here) on my 20m2 x 18mm Fibre cement deck (on steel frame).
The deck is outside and on the sunny side of the Australian Sun = 60degC sunny day surface temps.
I'm doing a french lay with 300x300 300x600 and 600x600 tiles.
I've used an 8mm notched trowel + double buttered + tile leveling clips.  *1st problem* - after a few weeks the gripset lifts off any substrate with Sikaflex FC11 polyurethane sealant. I belive this to be a case of "Do not apply to solvent based sealants"....that's my first problem - not this focus of this post. *2nd Problem* - Tile leveling clips. If not used correctly they can lift the tile up enough to cause drummy tiles....discovered...remedied....ongoing awareness. *3rd (main) problem* - Using Conflex tile adhesive I have been finding a couple of drummy tiles after a few weeks. They were very easy to lift off and I discovered the adhesive hadnt actually stuck very well to the Gripset38. Reading the Gripset instruction it says "use a polymer modfied cement based adhesive". I cant find anywhere if Conflex is polymer modified. Trick here is - if its not....Q....*Which one can someone recommend*. Be good if its a Bunnings carried line - but not essential.  *4th problem* - I think the loosening adhesive has caused my grout to crack - which after rain, I think the adhesive (creamy coloured) has seeped through and stained the dark grout. I was thinking of degrouting a couple of millimeters and going over the whole shebang with coloured silicone. This may be my easiest solution but not the best. Lifting all the tiles up and using the correct adhesive may be better - although harder....(including cleaning all the tiles of old adhesive). 
PS - I've used coloured silicone in some full length tile runs as an expansion joint filler (sheet joints) instead of grout.

----------


## wspivak

Hi Billy22Bob, 
In order... 
1: Sounds like the 11FC wasn't fully cured when the 38 was applied over the top.  I'd recommend using a Hybrid Polymer (SMX) type of caulk in future.  Alternately, use the recommend Gripset Elastoproof B10/B50 rubberised tape.
2: Yes, you're right.
3: Reading the data sheet for Conflex, it suggest that you use the Bostik Ultra NP Primer on non-porous substrates, which waterproof membranes fall into.  My recommendation is to use Construction Chemicals Monoflex - it's actually quite amazing how good it is.  I don't think you can get it at Bunnings, however, if you contact Construction Chemicals in your state, they should be able to advise you as to where you can procure it.
4: Without re-tiling with a better bonding tile adhesive, you're likely to see continuing problems as more tiles pop loose over time.  I'd recommend re-tiling with a better tile adhesive.  Think of it as short term pain vs long term gain. 
Good luck! 
PS, if you're in Victoria, we can supply you with Monoflex - check Home | The Waterstop Shop or call us on 03 9569 7687.  We are however on holidays from the 24/12 to 8/1.

----------


## Billy22Bob

Thanks Wspivak.
Found a Modified Polymer cement/rubber based adhesive CTA's Prohesive Range = Proflex at $36 "mates rates" from Beaumont - think I got ripped off, much more expensive than the $20/bag Conflex from my Chinese friends. I bought 1 bag to trial. 
Salesman seemed to have a reasonable knowledge of tiling (_I guess that's what makes a good salesman_) and he mentioned two important things....
Note: this is a sunny side deck 20m2....
1) Don't let the membrane sit in the sun too long as it will UV age quickly - eg: 1month is too long - do a fresh coat prior to tiling.
2) Apply some "Modifier/Primer" to the Membrane just prior to tiling as it will assist with adhesion. 
Only bought 1 bag - I'm going to repair a few areas and see how it goes. 
I am a little concerned with another post I read about using rubber based adhesives...."_Ultraflex should be okay on your waterproofed shower-recess walls. The only thing is - make sure you trowel it "vertically", so that the little ridges of adhesive formed by your notched trowel end up vertical, rather than horizontal. This is so that the dried adhesive in service ends up holding on to as little of the water that makes it through the wall tiles as possible. The reason this is important is because Ultraflex is also rubber-modified, and the rubber component of it doesn't particularly like moisture in "standing" quantities. For this reason, you definitely shouldn't use the Ultraflex on the floor of your shower recess_" 
I suspect the floor of a shower recess is similar to a rain sodden balcony application - so should I be using something with rubber in it in the first place???

----------


## wspivak

Hi Billy22Bob, 
Gripset 38 types of membrane (SBR based) shouldn't be left in the sun for longer than a 2-3 weeks prior to tiling.  If you have done this, then you'll need to prime with the Gripset OP Primer (AKA Gripset Betta Super Primer) and then re-coat with one more coat of membrane over the top. 
As for your concerns about tile adhesives... 
Tile adhesives by their nature have to be waterproof once dry.  Unless you get a bad batch (or use a particularly cheap & nasty product) it shouldn't re-emulsify under almost any circumstances.  The concern with respect to what you read is misplaced - however, when tiling, the notches should always be angled so as to point towards the leak control flange, so as to allow water to drain properly. 
In my opinion, you'll be fine with respect to the polymer/rubber modified tile adhesive. 
Hope that helps.

----------


## Billy22Bob

Thanks a mill - comforting words.....now "the process"....
Some tips required (if any)....
20m2 of 600x600, 300x600 and 300x300 tiles.....~100 tiles.....=ouch
1. Cleaning old glue from tiles.....previous process chip chip chip with a hammer and bolster on a blanket on my lawn + finish with a continuous diamond grinder (segmented may be better) = hard work....
Ideas?
Thought of an air chisel....hmm....

----------

