Cutting Granite

[DC_INC]

Is there a special blade for cutting granite? I want to polish the exposed cut edges. I want to cut the tile with as little chipping as possible. Is this unrealistic?

First time on granite....any advice is appreciated. Also, on a vertical plane, how will granite hold up on top of ditra? The tiles are 16" x 16" x 3/8" so they are pretty heavy.

Thanks for your help!

[ceramictec]

I use a regular Porcelain blade and it cuts Granite easy.

the second question should be.... how well will the tile hold up on
your Ditra on your Subfloor that passes Deflection

good if you have a strong enough subfloor.

[jadnashua]

The tiles are held up by pillars of thinset...the Ditra is not actually holding the tiles up. You need to read the installation manual http://www.schluter.com/media/DitraH...9-2007-ENG.pdf. A stone tile requires a two layer ply floor and twice the stiffness of a floor suitable for ceramic.

How clean the edges are depends hugely on the quality of the blade, the suitability of the blade for the medium, how well aligned the blade is to the sliding table, and the stone itself. Some stone is very fine-grained and has few inclusions or imperfections; others have large crystals (that can be loose and fall out after being cut), or small cracks, that no mater how good the saw and blade, will chip. The tile's factory edges are probably just cut, but could be ground. Polishing the edge of granite can be done on-site, but the quality of the result will depend on your methods, materials, and technique. It can be time-consuming.

[DC_INC]

Well I'm not laying the granite tile on the floors, it will be on the side of a kitchen island constructed out of exterior grade ply. Vertical not horizontal. I don't want to use CBU because of thickness issues so I wanted to know if ditra can be used on a vertical surface. The 1/8th difference makes a big difference on this install. Since the pillars are what is supporting the tile, and unmodified wont stick to the plastic, am I correct to understand that Ditra is floor use only (or any other horizontal surface)?

[Tool Guy - Kg]

Yes, you can use unmodified. While it won't stick to the plastic, the thinset will lock into the dovetail-shaped waffles very tightly. So, yes, you can use Ditra on a vertical surface if you want.

Is this the only surface you're working with Ditra on? Or are you also covering the top of the island as well? If the vertical is the only surface, why not use Kerdi or Nobleseal TS instead? You'd save even more thickness and would be easier to work with on the vertical surface.

[DC_INC]

I'm new to Kerdi. Will it work well to set tile directly on top of plywood? These are heavy 16" x 16" granite tiles. It is the only vertical surface being tiled, the top of the island is getting CBU.

[Tool Guy - Kg]

Before we go any further, what plywood are you using for the countertop? And is thickness an issue?

[DC_INC]

Three laminated layers of exterior grade ply CSP (canadian spruce plywood). All 3/4" thick for a total thickness of 2.25". the span is supported by cabinets underneath that are made of 3/4" melamine so its very stable.

Thickness is an issue on the sides of the island. I dont want to go too thick with CBU or other underlayments for the tile becuase it will mean my spacing on the top of the island will have to be increased. I fit 4 tiles perfectly across on the top which overhang to hide the exposed edge of the tiles going down the sides, but only if my underlayment doesn't exceed 3/16" - 1/4"

[Tool Guy - Kg]

Wow, that's thick. No deflection problems there. You could use Ditra or NobleSeal TS for everything (including the top), your choice.....I'd pick whichever gives you the easiest thickness to work with.

If you don't have any more need for the material other than this small project, I'd probably choose one of the Schluter products because you can buy small quantities from Tile Experts.com

[DC_INC]

Thanks for the advice...

I will go with ditra and post pics soon. Hope this goes as planned, and if it does....should look great !

[Tool Guy - Kg]

Realize that the moisture from the thinset will soak into the granite and may darken it for some time before drying out. No worries, but it may be a few weeks before the tile looks back to normal.