Floor tiles on walls and other advice needed please

[slartibartfast]

Hi

I'm sure these questions have been asked before but I can't seem to put the info together to understand what I need for my situation, so any advice would be gratefully received.

I'm planning to tile my bathroom using floor tiles on the walls as well as the floor. I am using 33CM x 33CM x 8mm ceramic floor tiles purchased from wickes. The wall area is approx 9m[SUP]2[/SUP]. Some of the walls are made from a strange type of plaster blocks (but are basically plaster) and partly painted, the other walls will be fresh plaster. I have cleaned off all the old tile adhesive and now have a pretty flat and stable surface to tile onto. What tile adhesive should I be using?

Secondly, the floor is freshly laid 18mm moisture resistant chip board over 50x170mm joists spaced at 410mm. The floor area is approx 2.5m[SUP]2[/SUP]. Do I need to lay plywood over the top or can I seal the chipboard and tile directly onto it? And what tile adhesive should I use?

I'm on a tight budget so I'd prefer to use a "best of the rest" adhesive and grout rather than shell out top whack for the very best.

Thanks in advance for any advice.

 

[charlie1]

TILES ARE TILES!!, ONLY CONSIDERATION IS WEIGHT LIMITATIONS FOR WALLS!<-- OOPS SHOUTING :-O

You might need to remove the paint from the walls if it has not bonded correctly, to test this, put some duct tape on your wall, leave for 10 min, then peel off, if any pain comes off with it then remove. Do this in different areas!

If ok....

I would use mapei P9 cement adhesive for your walls and floor as its slow setting. You will need to prime and key the area painted if you are not removing the paint! I would use a 10mm trowel for that size of tile assuming your walls are ok!!

Overboard floor with either cement boards(preferred) screwed and glued with rapid set (flexi) using 4mm notch trowel OR 18mm plywood screwd down every 300mm!!

 

[Rich]

Hello and welcome to the forum.
You will need to check the weight of these tiles. Each wall will have its own max holding weight and you have to be careful not to exceed these.

This is a guide
Gypsum plaster (finish plaster) - 20kg/M2
Plasterboard (direct to paper face-no skim) - 32kg/M2
Tile backer board - up to 60kg/M2 (refer to supplier's guidance)

Also the paint needs to be removed.

I would over board the floor with a 6mm cement board as chipboard is not good to tile onto.

With regards to adhesive, you will want a cement based (powder) adhesive. If you are confident with your speed, then I would go for a standard setting adhesive.

Have a look through the link below and see if there is a Tile Giant near you, pop in there and they should be able to sort you out.
Mapei: Tile Giant Store Finder...

 

[White Room]

Hi and welcome..

 

[paul damian]

Welcome to the forum, rich has your questions answered .

 

[DHTiling]

TILES ARE TILES!!, ONLY CONSIDERATION IS WEIGHT LIMITATIONS FOR WALLS!<-- OOPS SHOUTING :-O

You might need to remove the paint from the walls if it has not bonded correctly, to test this, put some duct tape on your wall, leave for 10 min, then peel off, if any pain comes off with it then remove. Do this in different areas!

If ok....

I

would use mapei P9 cement adhesive for your walls and floor as its slow setting.

You will need to prime and key the area painted if you are not removing the paint! I would use a 10mm trowel for that size of tile assuming your walls are ok!!

Overboard floor with either cement boards(preferred) screwed and glued with rapid set (flexi) using 4mm notch trowel OR 18mm plywood screwd down every 300mm!!

On a timber floor..?

 

[Qwerty]

On a timber floor..?

My thoughts exactly. How about keraflex or proflexible on floor. Everything as Rich says though

 

[charlie1]

On a timber floor..?

Sorry, just reread that, If using cement boards you can use P9?? no? Use kera flex to install the cement boards! Or just use keraflex on the 18mm plywood!

 

[slartibartfast]

Thanks for all the tips and suggestions.

I'm on a tight budget so I'd prefer to tile directly onto the chipboard because cement board and another load of adhesive will make quite a difference to the overall cost. The chipboard is screwed down every 300mm already. Would this be suitable for tiling directly onto the chipboard:

Mapei Keraflex Maxi Grey Standard Set Flexible S1 Adhesive 20 KG

The tiles weigh about 16kg/m[SUP]2[/SUP] so with the adhesive and grout I'm pushing the limit for the plaster over plasterboard, so I'll tile directly onto the plasterboard instead of getting it plastered.

I'll try to get all the old paint off the walls, what's the best way of getting it off?

 

[charlie1]

Yeah, your hitting the limit on the weight there! max 20kg per m2 for plaster! Chipboard is not suitable to tile on to! Over board with 15mm plywood and prime back and sides with Mapei primer G! Use keraflex or keraflex maxi if you require a longer setting time, screw the ply down every 300mm!!

Good luck

 

[DHTiling]

Thanks for all the tips and suggestions.

I'm on a tight budget so I'd prefer to tile directly onto the chipboard because cement board and another load of adhesive will make quite a difference to the overall cost. The chipboard is screwed down every 300mm already. Would this be suitable for tiling directly onto the chipboard:

If the budget is too tight to not do it properly ,then the option to not tile is there.. We can only advise the correct way to do it and tiling directly to chipboard isn't an option i would consider..

 

[Rich]

I couldn't agree more with Dave. If you can not afford to do the prep then you will just be throwing money away as the tiles are very likely to fail. Chipboard is not a suitable substrate to tile onto with any adhesive. Have you thought about using another covering for the floor? If you are adamant on using tile then the correct preparation must be carried out if you want the installation to last any length of time.

 

[slartibartfast]

Thanks again for the replies. I'm not trying to go against anyones advice, I just want to fully understand why it must be done a certain way. Now I understand that I can't tile onto chipboard under any circumstances I will discount that option.

I was originally thinking I'd tile the walls and then use lino on the floor but as the tiles were only £5sq.m and are floor tiles I thought I might as well use them on the floor too. If money was no object I would use the very best materials, do everything by the book and probably spend quite a bit more than £5sq.m on the tile. In fact I probably wouldn't be doing it myself if money was no object ;-) I'm just trying to understand the best technique weighing everything up. There's more than one way to skin a cat so I just wondered if there were any options other than to use more boards over the floor.

I'm not keen on overboarding with 15mm plywood as the build up of thickness would mean a step up into the room so it looks like cement board is the way to go. Just wish I'd asked sooner, I could have laid the floor in plywood to start with and saved myself this bother!

I'm struggling to get the old paint off the walls. Sanding is taking ages and I've also tried scraping it off with an old chisel. How would a professional do it?

 

[DHTiling]

If the chipboard is deflection free, then over board with Hardibacker 250(6mm thick).. the build up is minimal and you have a perfect substrate to tile to..

 

[slartibartfast]

So, I'm going to use 6mm cement boards stuck to the chipboard with keraflex maxi (I can't get normal keraflex near me), then stick the tiles to the cement boards with keraflex maxi. I will also use keraflex maxi on the walls.

Does that sound ok?

Do I need to seal any of the surfaces with pva first? (bare plasterboard, chipboard?)

I have now managed to get the paint off the walls, I found the best thing for getting the paint off was a "heavy duty stripper" from B&Q. It is a 4" blade with a long handle that slices the paint off the walls. I found it was a bit too sharp to start with but after lightly scuffing the blade with sand paper it was fine. I managed to clear about 5sq.m in a couple of hours

Should I scratch the surface of the walls to help the adhesive grip?


Thanks again for all the replies.