Hi there. I'm new on the forum,
I've bought myself 50M^2 Travertine and am trying to ask all the right questions before setting out. Conc floor without UFH.

Here are some Q's:

• Slab is 1 year old, conc screed 6 months. Seems to be no dusting. Am I likely to need a acrylic primer?
• Some of the tiles will be on top of old Marleys and another area where the screed is painted. I assume the acrylic primer is appropriate here?
• Couple of spots where old slab meets new. I need to put in a joint for movement and possibly some uncoupling. The old/new joint isn't perfectly straight though, so even with a soft foam+ silicone gap, the edges of the tiles might get bonded to the wrong side for 1-2cm. I'm considering a strip of (say) 10cm wide builders polythene under this section to prevent adhesion. - Is this sensible or silly?
• (I have read Dave Hawe's "uncoupling membrane explained" and looked at the Shulter data, but I still can't answer this.
• My travertine is "light filled/honed". I have bought "ivory" grout. Might I have been better off with white grout? (Ideally you say no )

Rgds

Hi and welcome...

Jasmine grout would be so much nicer.

Hi Justin, and welcome to TF, is your subfloor concrete or screed? either way I would prime with the primer recommended by whatever adhesive you decide to use.

I would not advise tiling onto Marley tiles, or paint, can these not be removed?

Expansion joints are stronger if you use pre-formed, rather than just silicone, de-coupler would probably help overcome different sub-strates. hope this helps.

Hi Phil.
New floor: I have conc slab (1 year) above insulation, 50mm screed (6 months).
Older part of house is solid slab+screed (no insulation).
Joints between these two floor areas in 4 doorways (The extension "wraps around" the old).

The Marleys in the old part of the floor are actually the DPM. Builders in ~ 1973 then seemed to do it this way so I'd sooner not remove them.

I just looked up the expansion joints. I guess you mean these. Movement Joints, Expansion Joints And Control Joint Profiles - Schlüter-Systems They look the part, I'll try to get some. Farnborough. Not sure where though..

I wsa not intending any other joints only the old..new slab areas. There is no underfloor heating and longgest run (before old/new) is 8M on the old. The slab in this area is one piece but the screed is in a few sections so there are joints but only in the surface screed.

I assume that some cracking (shrinkage in the screed only) in the 6 month old new floor probably isn't an issue, I'm expecting these to be stable now.

Originally Posted by 1justin

Hi Phil.
New floor: I have conc slab (1 year) above insulation, 50mm screed (6 months).
Older part of house is solid slab+screed (no insulation).
Joints between these two floor areas in 4 doorways (The extension "wraps around" the old).

The Marleys in the old part of the floor are actually the DPM. Builders in ~ 1973 then seemed to do it this way so I'd sooner not remove them.

I just looked up the expansion joints. I guess you mean these. Movement Joints, Expansion Joints And Control Joint Profiles - Schlüter-Systems They look the part, I'll try to get some. Farnborough. Not sure where though..

I wsa not intending any other joints only the old..new slab areas. There is no underfloor heating and longgest run (before old/new) is 8M on the old. The slab in this area is one piece but the screed is in a few sections so there are joints but only in the surface screed.

I assume that some cracking (shrinkage in the screed only) in the 6 month old new floor probably isn't an issue, I'm expecting these to be stable now.

In 71 they were'nt using marleys as a dpm and if they were council propertys they would have had a clerk of works doing inspections during construction..

The house was about '73 or 74. Estate detached. Not council. Definitely uses Marleys- the entire ground floor is done. They are set in bitumen.

Thats how they were fixed, blackjack it was called..

Originally Posted by whitebeam

Thats how they were fixed, blackjack it was called..

Yes Mark, we knew it as ATA (asphalt tile adhesive), the tiles would be thermoplastics, Marley and others made them. We used to have to heat the tiles on a hot plate or use a large nozzle gas gun, this made the tile soft & pliable, we would black-out a whole floor, let the adhesive go off. Then heat the thermoplastics to a high temperature and lay into the ATA, this melted the adhesive and brought it back to a sticky consistency. Talk about the good old days

You don't appreciate how lucky you were

.....then Phil went out to his night job....in the black and white minstrel show..