Hi guys,

Thanks for giving this a read. I have two short questions related to my washroom tile installation. Thanks for any advice you can give.

1) I've installed some porcelain 24” x 12” floor tile. I understand sanded grout is stronger and therefore better than unsanded, but will I scratch the tile with sanded vs. unsanded? Is there a better product that won’t damage the tile surface? Do you have to seal one and not the other, or will both require sealing?

2) I’ll be soon installing subway tiles on the walls above my new tub. There is a Kerdi waterproofing membrane on right now. I’ve heard a few people say that it is good to put strip of wood near the bottom of the tiled area, and work up from that wooden strip. To do this, I’d obviously have to drill through my Kerdi. If you were to do this, what would you recommend patching the screw holes on the kerdi with? Grout? Am I being WAY to cautious to even ask this?

This isn’t really a question, but just a note… I went to everyone’s favourite… Home Depot, and asked for unmodified thinset, as required by Kerdi. The “tile guy” said he didn’t have any. Does that seem a little strange to you? Is unmodified that rare??

Thanks for reading!

Hi welcome,

1. If the grout joints are 1/8" or wider, use sanded grout. It will not scratch your porcelain tile whether glazed or not. Seal the grout.

2. Use a wide board so you'll be able to bond a Kerdi patch and still have a 2" overlap from the hole. Or just place a dot of silicone in the small hole. Do not spread silicone too far. The orange place is not a good place for un modified thin set at all. Even when they have one, they do not have a good one.

What other stores and brands of thin set can you get near you?

Jaz

If your tile joints are 1/8" or more then you use sanded grout.
Sanded won't scratch the tile.
You only need to seal the grout joints.

You can screw a pc of plywood to the wall and then patch it after with a shot of silicone. If you don't want to compromise the Kerdi, screw plywood legs to your starter strip and the weight of the tile will keep the support in place.

If your Home Depot carries the Custom line of products then look for one called CustomBlend.
If you can find a Mapei dealer, a better unmodified is Mapei Kerabond.

Man, I'm slow on the keyboard.

Great info, thanks very much guys.

Jaz, I live in Vancouver. We have a few other big box stores around here... Rona being the largest. I'll search around for a tile supply place as well.

I'll try looking for the two products that RC listed at the big orange box. Thanks again.

Ames tile near Brentwood mall in Burnaby is a great supplier with great service. Look up their web site.

A starter strip of wood is seldom necessary. just get a bag of tile wedges. Draw a level line at the top of the first row of tiles. Then stick on your first row and insert wedges between the tile and the floor to make the whole row perfectly even. Work up from there.

With subway tile modified thinset will cure even over Kerdi. This is because the tiles are small and porous and the thinset has access to air. Completely different story if you are using larger tiles because you need a thinset that cures in an air deprived environment.

Thanks for the advice and store recommendation, pistolpete!

The only reason I'm looking at unmodified is that I glanced at Kerdi's website and they recommend it. In fact, they tell you to use it to adhere the kerdi to the backerboard, and then again to stick on the tiles.

The subway tiles I'm using are slightly larger than standard. Something like 4"x10". I might as well find a good unmodified...

You are right to look for unmodified. I hope I did not confuse the issue. For adhering Kerdi you definitely need it. Masterblend by Custom Building Products is a decent choice and commonly available in vancouver.