Advice On Bathroom Prep.

[Cabnero]

Hi guys I was hoping to get some advice on prepping my mum's bathroom for tiling. The floor is floorboards covered in vinyl tile but as there is going to be moving of pipework most of this had to come up so was going to replace it with 18mm wbp ply primed underneath and edges. Although only a small area wanted to use a leveling system out of curiosity. Floor tiles are 60 x 60 porcelain and wall tiles are 60 x 30. Wanted to match the grout lines on the floor and walls. Do the clips in the leveling systems act as spacers in which case I would need to use this for the walls also?

The walls are half tiled and half I think rendered with a very bubbly finish which had been painted. Almost like artex. I was going to dot and dab plaster board the tank. I was also curious about using 10mm marmox. Would this be OK. One of the walls is external. Are there any considerations for this.

Many thanks for your help

 

[Tile Shop]

As far as i know, the Raimondi clips are the only ones that can be used as spacers.

I asked this before because Genesis claimed you got a "constant 1.2mm" grout line. However if you want to do things by the book (british standards), floors need a minimum 3mm. And on a wooden floor, with 60x60, you'd be risking it if you went any smaller. So unless you're using the correct Raimondi clips, use the 3mm spacers in addition.

Wall can use 2mm minimum. But if you want the grout lines to match up with the floor you'll need to check that the tiles are compatible, as because of nominal sizing, the may not be exactly 600x300. Might be 601x299 for example. So you'd need to either use whatever spacer would suit, or deliberately stagger the joints to the floor.

As for the marmox, that will be fine as long as you tape the joints before tanking. Double check the Marmox website as they have a very handy installation guide.

 

[Cabnero]

Thanks for the reply Paul C. Out of interest why would it be risky going less than 3mm on wooden floors with 60 x 60.

Also would it be advisable to use ditra?

Finally I forgot to double check which would be the best trowel size to use. I was think 8mm for the wall and a half moon for the floor. Thanks again.

 

[Cabnero]

Sorry forgot to ask if they are nominal thickness which they probably will be, they are only from tile giant about £30 sq/m is there no way at all too match the wall and floor grout lines if I use a 3mm line on walls and floor?

 

[Tile Shop]

The flexible grout will act (to some extent) as a buffer to cater for any movement and vibration. the less grout you have, the less chance you have of the floor surviving any excessive deflection or the effects of shrinkage/expansion in the substrate. The lack of this buffer can lead to stress being applied to the tile which could lead it to crack. Ditra will help, but regardless of any membrane being used, BS still say 3mm minimum for floors.

If laying Ditra, you can use a 4mm mosaic trowel and then a 20x10 round notch trowel to fix the tiles. Being large format, it will be essential to "back butter" the tiles (both wall and floor) to ensure you get a solid bond and fill in the voids in the back print of the tile. For the walls, 8mm should be ok, but lay a tile, then remove it to check you have sufficient coverage before continuing, and adjust the trowel size if required.

Thickness of tiles.... should be uniform. its only the length and width that tolerances "might" occur. For £30, you'd expect it to be of reasonable quality so you shouldn't have anything to worry about. I was just referring to the possible difference between the wall and floor tiles. Loose lay a few on the floor and plan your layout before you start. and the mark the walls where you would expect the wall tiles to sit to see if you plan works out. Bare in mind you want to keep the cuts as large as possible. No-one likes to see a little slither

 

[Cabnero]

Nice one Paul C. Thank you

 

[Cabnero]

Sorry to bother you guys again but have been thinking about the above. The answers were really helpful but am now thinking a brick bond would look quite smart. Just wondering though, one side of the window is 400mm and the other is 260mm. The tiles are 600 x 300 so would you fix full cuts either side of the window or continue the brick bond all the way up on either side of the window, if you see what I mean. Also been looking at other threads. Is it correct practice to overboard 18 mm ply with a 6mm backer board? Would it matter if this wasn't done. Is 6mm the minimum board thickness or could you use 4mm. I think marmox does a 4mm board. If there are any dips once the ply is laid would over boarding be the best way to tackle it. I don't think the later will be an issue but it would be good to know. Thanks again.

 

[Spare Tool]

Sorry to bother you guys again but have been thinking about the above. The answers were really helpful but am now thinking a brick bond would look quite smart. Just wondering though, one side of the window is 400mm and the other is 260mm. The tiles are 600 x 300 so would you fix full cuts either side of the window or continue the brick bond all the way up on either side of the window, if you see what I mean. Also been looking at other threads. Is it correct practice to overboard 18 mm ply with a 6mm backer board? Would it matter if this wasn't done. Is 6mm the minimum board thickness or could you use 4mm. I think marmox does a 4mm board. If there are any dips once the ply is laid would over boarding be the best way to tackle it. I don't think the later will be an issue but it would be good to know. Thanks again.

Overboard floor, glue and screw 6mil hardi..foolish not to really.
How wide is your window?

 

[Cabnero]

Hi. The window is 1070mm wide and 1110mm high. Thanks.

 

[Cabnero]

Sorry guys to trouble you again. Do you have any thoughts on the previous message. Thanks

 

[Spare Tool]

Can't really set out the horizontal line for you without knowing what every measurement in the room is, vertically on the window wall its nice to centre the window but that wont work so id be looking at something like this..

 

[Cabnero]

Cheers Andy that's really kind. I was wondering whether to brick bond on the right of the window but would probably be to busy looking. Many thanks again. I'll stick some pictures up when is done.

 

[Spare Tool]

When you get to the corners of your wall try and make it look like a tile bent round the corner..ie. Half tile flowing round to meet another half tile..ish
Good luck..

 

[Cabnero]

Hi again chaps further to the previous advice a quick question re the floor. At the moment there are vinyl covered floorboards. These are going to come up and i'll nog out everything then screw 18mm wbp ply sealed underneath and sides. however there will be a couple of joints between the boards and the shower tray i 35 mm high and is one of those that sit directly onto the joists.

tiles are 60 x 60 porcelain floor area is small only 2.5 approx once the tray is in My questions are :

1) Is a 2 mm joint between boards ok
2) was thinking of using ditra but not sure if there is enough height available once the ply is down: i.e 35mm tray, less 18mm ply = 17mm. 10mm tile thickness, (approx got to double check) leaves 7mm. tile adhesive goes down to approx 5mm leaving only 2mm. Is this enough for ditra plus adhesive without taking the tiles over the top of the tray? If not can I tile straight onto ply if the floor is nice and solid (which it will be!) i also so a product called mapetex which is thinner. Would this be suitable? You have to use a 2 part addy with this. would that be ok to use to lay the tile.

Many Thanks

Ernie

 

[Cabnero]

Sorry fellas but are you able to help me with this? Double checked the flight tiles they are 8mm thick. Thanks

 

[Ollie02948]

Are you wanting tiles to finish flush with top of the tray?

 

[Cabnero]

Hi Ollie. Thanks for answering. Originally I just wanted to loose as much of the tray as I could. I guess it may look better if they did finish flush but as long as they don't go over the top of the tray I'll be happy. I will bow to your knowledge though. Thanks.

 

[Spare Tool]

Can the tray not sit on the ply, problem solved

 

[Ollie02948]

If your wanting it to finish flush you would have to build a base in the sub floor same size as tray to make it flush.

 

[Cabnero]

Wow talk about not setting the wood for the tress! I didn't even consider sitting the tray on top. I was just thinking about it on the joists. I cab speak my mum about that. If we go down this road can i ask, you guys would always either overboard the ply or use ditra. You would rarely if ever tile directly on to the ply as a rule.

Ollie thanks for you're answer but can you clarify what you mean about the base. I put in an impey aqua Dec in at home a few years back and I plyed in between the joists. Is that what you mean? If so then I need to worry about the heights with the tile plus ditra.

Thanks again foryour continted assistance

 

[Spare Tool]

You could lay 12mill ply on joists and fix tray on it, 18mil ply rest of floor then overboard with 6mil Hardi and tile and you'd end up with around 5mil lip below tray

 

[Cabnero]

Thanks Andy that makes sense. Would you mind advising re garding my previous message. As a matter of course di you guys not tile directly onto ply. I have done this in the pay and not had problems but id rather be 100% rather than 95% . I have only done three courses but have tiled four bathrooms in the past and id ratger be sure. I hope you guys don't mind these questions just wanna get things right. Thanks again.

 

[Ollie02948]

Like it says in previous posts. Make sure you overboard it with a suitable tile backer board.