Tling over old tile adhesive

[Martyn Leeds]

How much prep does this surface need before re tiling? Will the new tiles adhere properly if old adhesive is left behind?

I think the actual question is, do I have to scrape up all the old adhesive, or can I just go over it??

Dunno, we can't see how good or bad it is. Maybe a picture might help?
A scraper with a blade on it should be able to tackle it..

What does the Tiler say about it?? Is he happy with the prep??

 

[Stef]

I would remove as much old adhesive as physically possible.
How thick is the ply?

 

[rich hand]

If the Fastflex cracks I have already advised the owners that the joists should have been strengthened and that 15mm ply (not 6mm) should have been put down. They want to trial this situation rather than remove the bathroom suite, especially since it is hardly costing them anything.

Maybe the old adhesive was flexible standard or simply standard non flexible we do not know. However, it has stuck to the ply well just not the ceramic tiles. Since it has stuck to the ply well I was wondering if it really needed to be removed. It does scrape off if necessary though. There is only a couple of mm depth of adhesive.

The ply is on floor boards beanz.

On this job, I am acting as the tiler, I have done much work with stone floor maintenance including tiling, just not tiling on board.

 

[beanz]

Have all the tiles come up whole? Are they definitely ceramic, and not porcelain? This sounds like the tiles needed to be back buttered. If it was solely deflection, I would expect some breakages really, although I suppose it could be a combination of the two.

 

[rich hand]

The tiles have come up whole. Actually, there is more adhesive on the tiles than on the floor but the adhesive left on the floor has adhered very well. It's as though the adhesive was not flexible and has fractured in the middle. The tiles are porcelain.

 

[beanz]

Ah! Okay, that makes more sense. Personally, I'd get as much of the old adhesive up as I possibly could.

 

[Martyn Leeds]

I have already advised the owners that the joists should have been strengthened and that 15mm ply (not 6mm) should have been put down

So its 6mm ply??
How well is it stuck down? Nails in every corner and 1 or 2 scattered around, as per Joiners usual prep standard?

Least you can book them in next year for it doing again. Cool.

 

[Stef]

This floor is not suitable to take tiles as a floor covering.
Rip up that 6mm & replace with 6mm Hardie backer board, make sure there is no deflection (bounce) in the floor or it will always fail.

 

[The D]

If it was not modified it would probably not have stuck to the porcelain tile at all. Personally I would not be happy tiling on to 6mm ply and would be advising taking the ply out of the equation.
Can’t understand why the ply can’t be removed it would not take much effort to lift 6mm ply and replace with backer board

 

[Gazzer]

As Deano says for me too.

 

[beanz]

If it was not modified it would probably not have stuck to the porcelain tile at all. Personally I would not be happy tiling on to 6mm ply and would be advising taking the ply out of the equation.
Can’t understand why the ply can’t be removed it would not take much effort to lift 6mm ply and replace with backer board

To be fair, that's been explained. Customer wants to try and fix tiles without ripping up the floor 1st. Upto them if they want to throw good money after bad..
Rich, have you tried getting the adhesive off the tiles yet?

 

[The D]

To be fair, that's been explained. Customer wants to try and fix tiles without ripping up the floor 1st. Upto them if they want to throw good money after bad..
Rich, have you tried getting the adhesive off the tiles yet?

the customer need to be told that 6mm ply is not going to work.

 

[The D]

sorry to be blunt but if you tile on to 6mm ply in my bookyou are the type of tiler I am happy to call a cowboy. If you have a problemwith that you can try and justify it

 

[widler]

Yyeesss saturday night fights, wheres me popcorn .
Im with dean beanz, why advise on 6mm ply, its failed once its gonna fail again !

 

[beanz]

Who says he's advised 6mm Ply!?! The impression I get, is that he's advised 15mm Ply, but they want to try this first. If he's going to get paid to do it twice, because they refuse to listen, good luck to him.
as for having a problem Deano, I'm no sad *** Internet warrior, you fill your boots mate.