Tiles falling off tanking - why!!!

[Gixerguy]

Hi again - I have yet another problem I'm hoping you can solve for me!

I've applied Homelux membrane tanking to the two walls of my corner shower. It's on the right way ie correct side to the wall. The walls are brick & plaster (finish coat) and I used Granfix CFTA powder addy. It seems to have stuck like @@@ to a blanket lol

However, two days later I applied a few tiles (ceramic 20x10 8mm) using the same addy. Where the tiles are on the wall they're fine but after 24hrs the tiles on the tanking will fall off with a little nudge and the addy is wet still - you can literally wipe it off. The room is suitably warm and dry.

Homelux say that Im doing it all right and that Granfix is fine for this use.

I don't understand whats gone wrong!

As always I really appreciate your help and advice,
Many thanks guys!

Darren

 

[doug boardley]

I'm baffled by that mate, are the back of your tiles dust free?

 

[Gixerguy]

Hi Doug, the tiles are clean i wipe each one with a sponge that is very very slightly damp it barely changes colour of the tile but gets the dust off. It seems that the edge of the addy dries but the rest cant lose the moisture? But with powder i thought the bond was chemical not water loss?

Im no pro but cant see any obvious cause!!

 

[doug boardley]

any chance it was a duff batch of adhesive?

 

[Gixerguy]

Im thinking it's prob not as the addy has stuck to the walls perfectly - the only variable is the tanking - just noticed that once the tile is off the addy dries in about 1hr and sets fine so it seems that the tanking stops the moisture leaving ??

 

[doug boardley]

I'm at a loss then mate, what tiles are you using, ceramic, porcelain, glass?

 

[Deleted member 9966]

Did you prime the tanking membrane before tiling on to it?

 

[Gixerguy]

The tiles are ceramic,

I didnt prime the membrane - Homelux dont advise this.

I have tried a sample area with BAL SPF - might have to wait 'til tomorrow to see if it bonds. I WILL post and let you know.

Thanks for your replies all!!

 

[Gazzer]

Did you prime the tanking membrane before tiling on to it?

You dont need to prime the tanking after.

 

[jay]

is it granfix CFTA STANDARD ADH that you used

 

[Gazzer]

is it granfix CFTA STANDARD ADH that you used

Its a SPF

 

[jay]

yes but is it self setting:8:

 

[Diamond Pool Finishers]

mix a test patch up and leave over night ,from the same addy ,on a bit of board ??

 

[jay]

okay read data sheet and it seems to take 24 hours to set normally on porous surfaces tile and substrate so if you have tile and membrane it may struggle as this type of adh dries by absorption of moisture by tile and substrate there for it will stick to tile but might not to membrane unless left for a long time 48 hours plus doesn't mention membranes in data sheet at all/////////:8:


self setting adh set without the need of porous substrate or tile

 

[Gixerguy]

Thanks for your replies - heres an update lol
After many calls between Homelux & Granfix I'm being told it is quite likely that the addy I used isnt suitable for this tanking.
Homelux had originally said it qould be fine when I was researching the project but in light of my difficulties have looked deeper and suspect that it differs slightly from BAL SPF which is the preferred addy.
The tanking has also not bonded but come off clean leaving ALL the addy wet on the wall.
Homelux have been BRILLIANT and not only given advice throughout but are replacing my tanking & joint tape FREE OF CHARGE by next day delivery (tomorrow) and I even have a Homelux Tech Advisors personal number to update in the morning as to whether the SPF test works.
So although I'm just a joe public they're looking after me very well!!!!!!!
It does seem that as good as the Granfix addy is something upsets it when used in these circumstances. As promised i will update tomorrow so we can all learn from this lol
Thanks again all
Darren