I am re-tiling our bathroom. I have knocked of the old tiles and am left with the old adhesive in ridges about 1-2mm proud. Now, can I tile directly on top of this rough surface or should I try to make it smooth by removing the ridges (time consuming and very messy) or putting a thin skim of plaster on to fill in the gaps???

The new tiles are tumbled travertine mosaic 50mm square, but come in 300mm square sheets.

Any advice welcome....

[Edited on 24/3/09 by Slater]

are you using a "comb" style spreader?if so and the ridges fit into the groves in the comb then i cant see a problem,thats how i did mine many years ago and they are still up.
ps you know about the baton and spirit level?

like with most things, if you start with a good base the finished item should be good.

It's much harder to get all the tiles flat if you start with a rough surface.

also depends on your tiling technique, If you are the kind of person who puts the adhesive on the back of each tile before sticking it to the wall it won't matter so much but if you use the proper toothed spreader over a larger area to quickly cover the area then the flat surface will be much better.

Which method you use to get the flat surface is a matter of choice and whether the existing wall is sound.

By the sound of it you're new tiles are held in 300mm squares with a mat bonded to the back of the smaller pieces?

If so thena flat surface will be a lot easier to work from and achieve a good smooth/level finish. A light skim of plaster would be the quickest/easiest route I think.

You could have tiled over the old ones quite easily, but best to level up the surface and PVA it before you tile again. I just skim with thistle then PVA when it dries and tile. You use lots of adhesive if you don't fill the grooves in.

Ive tried a few ways in the past. By far the best result is on a flat wall. Your tiles probs werent cheap, they are worth a bit of skim first if you cant get the old adhesive fully off.

Why not get the sander out You can do snowman / ghost impressions while your missus kicks you through every room in the house (due to the dust - not cos tiling adhesive dust is a pheremone)


You might get away with it if it is truly 1 - 2mm proud and even across the whole wall, but those tiles do really need a good base.


I put small tumbled quartz tiles in a kitchen a while back, and also some natural slate down on a floor. i so wish i sealed them BEFORE grouting. Are yours pre-sealed? Big problem with these 2 sets was that they were all random thicknesses. I hope yours are uniform (should be if they are on a net backing).

Yes, I will skim it to make it flatter, I have a big bag of joint filler in the garage, so will use that, then PVA to seal it.

Darren
I have been advised to lay the tiles, then grout, then seal them. Apparently if you seal them before grouting then the grout can't penetrate the stone and will fall out.

Thanks

i think it depends on the type of tiles ref grouting / sealing methods. As you know - best to go with advice given by supplier.

The slate floor tiles were an utter nightmare to grout. Proper pain to wipe off. Then i read the instructions Doh! There were 2 different sealers i had to use though. Cant remember the names but one of them was before grout, other for after grouting and then once a year. (From Fired Earth).


I bet yours will look amazing once they are done. What are you using these Browny points for? Can you trade them in for a trackday pass out or trip to Mac#1 summers party at Newark (assuming there will be one).

Bear in mind that natural stone tiles are heavy and make sure that the wall can take the weight.

Phil

quote:

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Originally posted by DarrenW
i think it depends on the type of tiles ref grouting / sealing methods. As you know - best to go with advice given by supplier.

The slate floor tiles were an utter nightmare to grout. Proper pain to wipe off. Then i read the instructions Doh! There were 2 different sealers i had to use though. Cant remember the names but one of them was before grout, other for after grouting and then once a year. (From Fired Earth).

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The tiler that did our bathrooms used a steam cleaner to get the old adhesive off, worked well and a lot less mess than sanding.

Iank is spot on. I always use a steam cleaner. Let it soak for a few seconds then scrape off (easily). Left with a nice flat wall.

quote:

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Originally posted by theconrodkid
are you using a "comb" style spreader?if so and the ridges fit into the groves in the comb then i cant see a problem,thats how i did mine many years ago and they are still up.
ps you know about the baton and spirit level?

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If they are real stone 'travertine' and not imitations,then you will need to seal them before you grout then seal them again after - or that's what my supplier told me. Seemed to work anyway...

Be careful when you try to adjust them when they are on wet - travertine tiles are not as rigid as porcelain etc. and are quite easy to break...not cheap!!

another vote for the steamer to remove old adhesive.
get the wall as flat as possible first, makes things much easier.

check the weight per square meter of the tiles. 20kg is the max for a plastered wall including the adhesive. large travertine tiles usually are heavier than that but you should be ok with the mosaics.
i would use bal mosaic-fix for the adhesive and a 3mm notched trowel

as for sealing check with the supplier.

don't prime the walls with pva, get a proper primer