A question for the tilers

[depreciator]

For my bathroom floor. I'm back to the reno - I've been distracted by another project I probably shouldn't have started.

It's a long story, but I need to grout the floor now. The gaps are 12mm deep and up to 30mm wide in places. No, it's not bad laying - all will be revealed when I take some photos.

And I need black grout.

Now, I know that using off the shelf black grout isn't the way to go - it will crack.

So I'll be using a sand/cement/dye mix.

But I need to know the proportion of sand/cement. I'm thinking 1:1?

Scott

 

[RumpledElf]

If they're not really long 30mm wide gaps you don't need anything fancy. I had a lot of gaps that wide in my lounge as one wall was random natural slate and went in and out like ... er ... can't think of any non-rude analogies

Anyway, I just did the wide gaps towards the end of the grouting, when the grout was just starting to go off and was really stiff, so you really had to shove it into the gaps. Then wait a bit and use a damp (not wet) cloth to smooth it off and press it in even more if it starts to crack. You can see why this doesn't work with really long gaps, as you don't have much time to work with grout that is about to go off.

If you use really wet grout you're guaranteed cracking.

 

[The Underdog]

RE...my dad used to say..."in and out like a fiddler's elbow."

 

[handyandy]

Just try the old 3:1 sand:cement with black oxide.

Cheers

 

[depreciator]

It's random slate. Well, random now that I have finished busting up the 600mm x 600mm black Brazilian slate tiles (50% wastage). But trust me, it's not going to look like a 70s bathroom. The gaps are long.
Andy, I reckon I'll get cracking with a 3:1 mix. I might have to do some tests.

 

[Rob Williams]

600mm x 600mm black Brazilian slate tiles.

Scott, did you have to use the word Brazilian in that sentence?
You know Rixter's over there in Perth trying to make up a Brazilian joke as we speak. I think you did that deliberately.

 

[depreciator]

I don't he'll have too much trouble given we're talking about the gaps/cracks between Brazilian slate.

 

[RumpledElf]

It's random slate. Well, random now that I have finished busting up the 600mm x 600mm black Brazilian slate tiles (50% wastage). But trust me, it's not going to look like a 70s bathroom. The gaps are long.

My trick won't work then Use the finest sand you can lay your hands on.

Its always slate the cause of these problems isn't it? The slate in my bathroom that was stuck so hard we simply couldn't remove it was grouted with regular, untinted mortar with coarse sand as aggregate. Looked awful. You would have needed a jackhammer to get it off. We tiled over it. Same slate is on the wiggly wall in the lounge and about 5 other places in the house.

Make sure you seal that slate REALLY well and keep the seal up. My bathroom slate was sealed with polyurethane but it wore through, and where it wore the slate flaked something severe. Poor quality slate that flakes in moisture in a bathroom? Argh! Its put me off slate for life!

 

[depreciator]

The slate around now, and the sealers, are better I reckon.
This particular slate has been down on the floor of a tile shop in Sydney for about 8 years and it's perfect.
Because slate breaks how it wants to break, I made a paper template for each piece.
I then scrolled the shape on the underside of the tile and made cuts to a depth of about 8mm using an angle grinder.
All pieces were individually sealed - edges and face - before being glued down. I'll be sealing again after grouting.
How's that for anal.
Gee, it's going to be a nice bathroom if I ever finish it - wait till you see the wall tiles.

 

[RumpledElf]

How's that for anal.

I wish you had done the bathroom in my old house all those years ago

 

[gerd]

Grout gaps 12mm deep and up to 30mm wide.

Blended Sand course and fine the type used to render. 4 sand to 1 cement add black oxide to suet.

Allow the grout to partially set. Using a sponge rub the grout back to a height level with the tiles. This method will give the same appearance as using fine sand without the shrinkage cracks..
( small sections at a time or the grout will go off before you can get a nice finish)

DO NOT WASH OF TO EARLY as that will result in grout well below the tiled surface.

Gerd