Hi Guys,

Should be starting my kitchen floor tomorrow, would have been today but the floor was more than a little uneven so took all day to sort that out SLC etc.

I am after a bit of advise before I go off at the deep end

Basically I am tiling onto a concrete floor that has a layer of water based SLC on top, for question should I apply a primer before adhesive?

The tiles I have a polished porcelain 600 x 600 they are from B&Q. I purchased some mapei mapeker rapid set flex from Tile Giant and was planning to use a 10mm notch trowel, but I am sure it stated on the pack to use a max of 5mm which seems a bit low for such a large tile.

Can anyone offer any advise on the best way top proceed?

Carpo

Hi carpo, I'd be using a 20mm (10mm radius) U notched solid bed trowel. 5mm is way to small imo to get 100% coverage. Make sure you give them a good twist as you lay them to get good contact. Also give the tiles a skim of adhesive with the flat blade of your trowel to fill in the profile studs on the underside of your tiles as you're laying them

no need to prime and I am doing similar tiles today with same trowel, should be ok when you bed it in

there is no need to prime slc as long as it is dry and dust free.
polished porcelain also needs sealing before you grout
as regards your trowel. you want a u notch trowel ,10mm is not big enough
i would use 15- 20 mm so you get 100% coverage of the tile.
i also think you would be better with a pourable thick bed adhesive.

Hi yes that adhesive is fine, as said no need to prime unless dusty, I would use 10 mm u notched trowel, and seal tile before grouting, good luck

Thanks for all the replies guys

Good job I asked first, so looks like I need to go back to Tile Giant today, may sound a silly question but a 20mm (10mm radius) U notched solid bed trowel is that 20mm deep by 10mm wide?

If I take the mapei mapeker back what would you recommend I buy instead? next door to Tile Giant is a Topps Tiles so should be able to get BAL if needed.

Thanks for the heads up about sealer, I was going to seal after grouting on advise of the shop!! again any recommendation on the best sealer to go with?

Carpo

And I would use minimum 3 mm spacers for that size tile

Right I checked and it's 20mm wide by 10mm deep, so will pick one up today. I am looking at buying the LTP MPG for sealing the tiles.

So just need to confirm if I should change the adhesive for a thick bed pourable?

I went for 3mm spacers.

Carpo

imo i would use thick bed pourable flexy. no need to back butter tiles, and i dont think 10mm deep is big enough. bal do a solid bed trowel think its 15mm .
you will only get 3m2 coverage out of a 20kg bag with a large format trowel so make sure you get enough addy

i think the 5mm is the max depth of finished adhesive not the trowel size most adhesives are 5-6 mm

As pete has pointed out , the depth stated on the bag is final bed depth and not trowel size.

Mapeker has a max bed depth of 5mm, on that size tile i would use karaflex maxi or Mapei P4 full contact adhesive, but if the substrate is flat enough then mapeker will cope.

Those polished porcelain tiles from B&Q have a 'transit wax' on them. You will need to clean off the wax before laying them. There should be a sheet of instructions in the box of tiles. Cheers Sean

Hi m8

60x60 is a big surface, when this is tapped into the adhesive there is huge suction between the tile and floor. This creates a problem when you lift a tile to reset it eg if you dont have enough adhesive under it and its sitting a bit low. The 2 main trouble areas are when laying damp travertine, they can snap and when laying on a leveler, the adhesive can lift the leveler.

Make sure the leveler is cured and that its an even light shade without any cracking.

You be as accurate as possible with your adhesive application so you dont have to lift.

Hope it goes well m8

..

Thanks for all the pointers guys, I got started this afternoon after getting some more adhesive, used 2 bags so far just laying 10 tiles. I couldn't get a pourable one so I went for the mapeker and back buttered each tile.

I also got a 20mm u notch trowel, I finished about 20 mins ago and am knackered it is not as easy as it looks, I did have to lift one or two tiles as they were a little low on one corner so I see what you mean by the suction.

Going to finish the one half of the room after work tomorrow, and then the other half may well get another SLC first to get it completely level, it was 10mm out but is around 2mm now after getting some SLC down over the weekend and it's still not fully dry yet, so cant tile there any way.

The point about the wax I take it that is on the polished surface and not the back where the adhesive go's? what do you guys use something like fairy? I know it strips wax from cars.

Carpo

2mm out on the substrate is fine..

An abrasive cleaner like lithofin abra clean or aquamix nano scrub is best to remove transit wax's. and they re on the face of the tile not the back

I did these tiles last summer & there was no transit wax on them........instead every single tile ( 25m2 ) had a sheet of plastic welded to it which was a pain in the butt to get off.....had to sit the tiles in the sun for 5mins to soften it enough to peel off!!!!

Removing wax sounds more favourable!!!

I have got the cleaner and sealer so should be able to crack on, the ones I have don't appear to have a plastic sheet on them, must just be a wax thankfully

Let you guys know how I get on.

Carpo

If the tiles are dull then they have a transit wax on them.. if they have the high polished look from the box then they are wax free.

Let you guys know how I get on.

Carpo

Photos???

Originally Posted by Dave

If the tiles are dull then they have a transit wax on them.. if they have the high polished look from the box then they are wax free.

Thanks Dave,

To be fair they look quite polished right from the box, they just have a SS written on in chalk which comes of easy enough, I guess it wont hurt to give them a good scrub anyway before sealing.

Carpo

Originally Posted by merlecollins

Photos???

I hope to get the it done this weekend so I will upload a few pics next week, unless I make a complete balls up

Carpo