New to tiling - How to prepare

[dobbadobbs]

Hi there,

I have recently put down some 25mm plywood on my upstairs bathroom floor, replacing the existing floorboards.

First question: How do I prepare these ready for tiling? Do they need any sealer?

Also, tiling the walls, we had a re-skim on the walls. The plasterer has made it really rough, and there is some cracks (he said it should be rough to act as some 'grab' for the tiles to adhere to.

Second question: Is this correct? How do I prepare this and what adhesive/grout should I use?

The tiles are some Capri Porcelain tiles from Wickes, they are 45 x 30 if I remember correctly.

Many thanks for your help,

Dobbadobbs


edit: I have recently purchased some Sovereign products and been impressed with the quality. Is there a Sovereign adhesive/Primer or anything else I can purchase from them as can get them at good prices?

 

[grumpygrouter]

The tiling face of the ply doesn't usually need priming but it depends on the manufacturer of your chosen adhesive. What you should have done however, is to seal the back face and edges of the ply before fixing to the floor. This helps reduce moisture effects on the timber. What adhesive do you intend to use?

As for the walls it's the first time I have heard a plasterer leaving walls "rough" so your tiles adhere better! Plaster skim will only safely take 20kg/m2 and I fear the porcelian tiles may be too heavy for this! Porcelain tiles require a flexible adhesive and grout and also for the floor, do you intend laying a backer board over the top?

 

[Dave_D]

I used a wbp (Weather and Boil Proof) pyl on my floors, well screwed into the floorboards, Flexible adhesive is a must.
We had to fix a job recently where the previous "tiler" forgot to remove the plastic wrap on shower tray :yikes: (counter-sunk into floor - for disabled access) and the adjacent tiles all lifted off within a few days, complete muppet.

DaveD

 

[dobbadobbs]

The tiling face of the ply doesn't usually need priming but it depends on the manufacturer of your chosen adhesive. What you chould have done however, is to seal the back face and edges of the ply before fixing to the floor. This helps reduce moisture effects on the timber. What adhesive do you intend to use?

As for the walls it's the first time I have heard a plasterer leaving walls "rough" so your tiles adhere better! Plaster skim will only safely take 20kg/m2 and I fear the porcelian tiles may be too heavy for this! Porcelain tiles require a flexible adhesive and grout and also for the floor, do you intend laying a backer board over the top?

Hi mate,

Thanks for the fast reply!

Had no intention of laying a board over the top of the floor. Is this a necessity? Is there any waterproof sealant we can use now the floor is screwed in?

We have already swapped the tiles once as we had a marble effect tiles (also from wickes) and they were huge, didn't really take into account the fact they were going on a stud wall. These 'Capri' tiles are much lighter and better.

Should the plaster be completely smooth then? Is there anything we can apply to toughen the plaster? Like Plasprime for example, which creates a mechanical key?

Cheers!


edit: the Ply is a WBP plywood, 25mm.

 

[Rich]

How rough is the plaster? Is it flat and level but he has keyed it for you or is at all over the place? If you are unsure of the weight of those tiles I would strongly recommend that you contact the supplier/manufacturer and find out. As grumpy said above skimmed plaster can only hold 20kg per m2, this is including adhesive and grout. The only way around this would be to install some plasterboard (un-skimmed) or cement boards, these would need to be mechanically fixed to the wall.

 

[dobbadobbs]

Hopefully you can see from this picture the plaster. It's quite rough.

Have just contacted Wickes and asked for a weight of the tiles. There is nothing on the box that indicates weight per m2.

 

[Rich]

That looks a bit rough to me and I dont mean in texture. Cracks are never good. I would like a much better finish to the wall before I tiled it to be honest. From the look of the pic, that it is only that wall has has been left like that? Are these tiles square edged? If so you may find it hard to get them flush if the wall is a funny shape. have you put a level on the wall to see if it bows?

What was the outcome of the phone call to Wicks?

 

[dobbadobbs]

That looks a bit rough to me and I dont mean in texture. Cracks are never good. I would like a much better finish to the wall before I tiled it to be honest. From the look of the pic, that it is only that wall has has been left like that? Are these tiles square edged? If so you may find it hard to get them flush if the wall is a funny shape. have you put a level on the wall to see if it bows?

What was the outcome of the phone call to Wicks?

Hi mate,

The wall to the right of the pic has the worst crack, almost like a spider web!

Tiles are square edged. We put a spirit level on the walls and found it bowed in one place - the middle.

Rang Wickes and they said they'd get back to me - haven't as of yet unfortunately.

Resigned to doing something with the plaster, as in it's current format, seems the consensus is that it's not workable, which is understandable.

Any recommendations on product for the floor....

So, a flexible floor adhesive + primer for the plywood. (We can get round the edges with a sealant).

And what product to use for the walls? Primer + adhesive?

As I understand this needs to be a powder based adhesive, not a pre mixed tub.

 

[kevin67]

that wall looks really rough, as above check to see that the wall is not bowed in any way or you'll have problems, also check where the plaster has cracked that it's not hollow when tapped or it will need re-doing

 

[Rich]

Do you have a Tile Giant near you? If so I would recommend Mapei products for the lot. The floor shouldn't need priming, I would over board with a 6mm cement board and then tile with a single part flexible adhesive like Keraquick. If you intend to tile directly onto the ply then I would recommend that you use a 2-part system, keraquick with laytex plus. The most important thing with the floor is to make sure that there is no movement in it at all. You must eliminate all bounce in the ply.

The walls will need a cement based adhesive, again I would prob go with Keraquick if you want a rapid setting adhesive or maybe Keraflex Maxi or Mapeker if you need a bit more time to work with it. The walls will need to be primed with primer G before tiling. Have a look through the link below and see where the nearest Tile Giant is to you. If you go in there and have a chat, they will sort you out with everything you need.



[h=3]Mapei: Tile Giant Store Finder...[/h]