Tiles coming off easy and net set.

[theandroids]

Hi guys, I put up hardiebacker and primed with Ball APD 1:1 ratio at 2 coats. After that I applied 2 coats of Aquadefense.
I started tiling (30mm×10mm) tiles, using 8mm trowel. I did a few rows, and left it to continue the following day. I Continued with the tiling but, by the next few rows I was not happy with it so I decided to start over. So removed them last night.

To my surprise the rows I did the day before (which should be rock hard by then) came of super dupa easy, revealing what looked liked crumbly dry/ish adhesive with had not set.

Also, the Aquadefense seemed damp and when removed the hardiebacker seemed damp too, like it sucked the moisture of the adhesive
Lucky I decided to start again as it looks like tiles would have fallen of by the weekend.

I have no idea what I've done wrong, maybe too much adhesive? Or maybe its the Aquadefense, as i covered joints with the same (Mapgrip D2 Ready Mix) adhseive prior, and adhesive dried fine.

Any ideas?

 

[Bill]

Because you have applied aquadefense, the walls have become non-absorbant and this nullifies the effect of the D2 adhesive.

D2 adhesive cures by evaporation so if you have enclosed the adhesive, then it will not set. (well not for some time anyway)

Are the tiles ceramic or porcelain?

have a look at the data sheet.

http://www.mapei.com/public/GB/products/2702-mapegripd2-uk.pdf

 

[theandroids]

The tiles are ceramic, do you recommend removing all Aquadefense? and tiling directly on the hardiebacker?

 

[Old Mod]

No, if it’s a wet area you need tanking. Change adhesive to bagged, not ready mixed.

 

[theandroids]

No, if it’s a wet area you need tanking. Change adhesive to bagged, not ready mixed.

Ok. So I can't use ready mix? Not really practice at the moment for bag adhesive. What's the "BEST" ready mix to use on Aquadefense?

 

[LauraCTW]

Not a case of 'best' tubbed addy to use here. Due to the nature of the product it will take an age to dry if used over tanking. Why not use a standard set bagged adhesive. Tub life of 2 hours type thing? Will mean a bit of mixing but I honestly wouldn't advise a tub to use in this situation.

 

[theandroids]

Any suggestions for bagged adhesive that will not go off quick?

 

[Andy Allen]

Weber set plus slow set...

 

[theandroids]

No, if it’s a wet area you need tanking. Change adhesive to bagged, not ready mixed.

" Do not use on metal surfaces and to lay nonabsorbent tiles onto non-absorbent substrates" wish I saw that on the tub.

Anywho, was on the phone to Mapei they told me to use KERAFLEX MAXI S1. Thanks guys.

 

[Slippery]

In my (limited compared to some on here)experience, I found Ardex p9 to be an excellent alternative to tubbed adhesive, easy mix and an 8 hour pot life, after about 10 mins stuck, you will struggle to get any tiles off!