Slate tile preperation

[d438a1]

Hi guys,

Just after some advice as will be starting to tile bathroom floor soon. We have bought 300mmx300mmx10mm slate tiles and i just want to run through my plans, so correct me if there are better ways please..

For the floor....

Subfloor is to be 18mm plywood screwed down at 200mm centres. On top of that will go 12mm hardibacker set using Rapidset flexible and screwed down at 200mm centres.

When thats all dry, i was going to use Rapidset flexible again, with a 10-12mm(?) notched trowel and lay the slate tiles. After its dried, i was going to seal with linthoseal (was recommened to me by someone) grout, then seal again.

For the walls...

We would also like to use the slate tiles to tile the bath surround (top and side panel) and also the shower cubicle walls (900mm quadrant). All of these areas have Hardibacker secured to it, apart from one of the shower walls which is the orginal plaster which is in good condition. Can I get away with using a smaller notched trowel for the bath frame or the shower?

Thanks in advance for advice

[Fred]

If the backs are flat, try an 8mm trowel on the walls etc, but to be honest theres not alot of difference with a 10mm trowel once set in place. Are all the slates 10mm thick or various?

I would be inclined to tank the shower area with Bal tanking kit, to be on the safe side. Also, on first sealing, try a small area and if it still takes the sealer, give it one more coat as some slate takes alot of it. Use cement away to get rid of any adhesive you get on the slate, but being clean will advoid this.

Hope that helps.

[wetdec]

Sorry obvious question I know is the slate :

Riven
Honed
Polished

Then people can have a stab at it for you...


..

[d438a1]

Yeah the backs are pretty flat. The tile packet recommendation is 12mm, which I am happy to use on the floor, but if i can reduce it on walls and bath frame that would be good.

I was going to tank it with dunlop tanking kit, as its a fair bit cheaper at screwfix. Unless its not that good?

Thanks for the advice on the sealant and cleaning material.

[wetdec]

Hellllllllo ..................

[d438a1]

It is Riven - uneven and rustic effect, that correct? Although its pretty flat on back

[wetdec]

lol ok, I ask because sealers react differently with the different surfaces.

You have a choice lythofin colour intensifier will give you a mattish finish lifting the colours or lithofin slate seal will give a sheen (the more you use the shinyer it will get.

Knock any slate splitting away off the tiles then clean them up with a damp/wet sponge, this will give a good idea of hidden colour and get rid of any muck.

When dry they can be fixed then when grouted seal them. If you seal the walls twice you could well get runs which you dont want. (your choice)

Hope this helps you a little.......

,,

[d438a1]

Great thanks for that. Any further advice on laying the tiles or thickness of trowel notch?

Thanks

[Dave]

Lithofin stainstop is good for slate as well if you want the more natural look or lithofin slate seal for a semi gloss look.....my advice is to seal first with riven slate.......can be a nightmare to get clean for peeps who are not confident at using slate....

I think you will need to back butter if the thickness is uneven to get a solid fix....

Make sure the slate is washed clean and dry before sealing......

[grumpygrouter]

You want to fix slate on a wall with a plaster substrate? Might be a touch heavy methinks!

[doug boardley]

no need for 12mm hardibaker on floor, 6mm would be better

[grumpygrouter]

no need for 12mm hardibaker on floor, 6mm would be better

Is there any real need for cement board at all with 18mm ply?

[Dave]

Is the 18mm ply onto joists.....?

[doug boardley]

was wondering that myself Russ after I'd hit the post button! certainly no need for 12mm tho'

[Grace'sDad]

Is there any real need for cement board at all with 18mm ply?

Not really, but if the floor can stand the additional height and cost, then so much the better IMO!

Besides, I've never been a fan of tiling onto anything that came from a tree.

[d438a1]

Yeah the 18mm is straight over the joists. The reason I used 12mm Hardibacker on top is to get some extra height to make the shower tray look a bit more recessed and hidden.

So my only concern now is about tiling the one 900mm wall where it is a plaster substrate, as the rest of the wall 1.5m is not going to be tiled.

Any suggestions?

Thanks

[Dave]

Depends on how heavy the slate is...it is going to be close to max weight....

[Fred]

ALL WHAT i'VE SAID............lol

[d438a1]

After looking at the wall again, I dont think it will be too much hastle to remove about 1m wide of plaster from the wall and then render it back up to the level of the plaster. The other part of the wall is going to be skimmed anyway, so that should be fine.