Installing slate flooring is about the same as installing a uniformly set or pressed tile system.
Most of the sub floor issues remain the same, with the sole exception being the matter of weight.
Being a natural product, some slates are actually quite heavy and may only be properly mined at a thickness to allow it to be shipped and handled.
Also, many slates require the thickness simply owing to the actual extraction process itself, rendered from rock as it is.
Trying to extract slate in paper thin slabs, for example, likely would not work, owing the strength and pulling stress on the rock itself.
The sub floor required for some of the heavier slates may mean a thicker plywood base, if indeed it is going on a wood surface.
On cement, obviously, nothing changes anyway.
Typically, your 1 1/4" base remains but checking with local codes or even engineering specifications gotten online for the weight of the material is smart.
So, alas, there is some math involved.
Weight can be a crucial consideration in not only the sub flooring and the tiles themselves, but also in the structural elements of those struts which actually support the floor itself.
It is entirely possible you have your heart set on that Brazilian Slate flooring and that it would mean partially rebuilding the structural underpinnings of your kitchen!It's not that bad though.
Even that is easily do-able, so fear not.
Once we settle the sub floor issue, a standard trick is to lay the slate tiles out in patterns which most resemble your goals.
Most flooring patterns are readily available at tile centers or from your own supplier of this slate.
You may absolutely play with patterns and even opt for something random in the end.
Clearly, a method of cutting slate to fit your patterns is required, generally consisting of a motorized wet tile saw with either a diamond blade or an abrasive blade setup placed on a skill saw.
There's much dust created with the abrasive blades, so bear this in mind and apply the necessary safety measures.
With this item functioning, you can safely cut your slate tiles to fit whatever pattern you might opt for.
Add:many slate tiles come in precut style, with definite patterns described for their use.
In these cases, the only cutting should be fitting the final tiles into corners and along edges.
When the pattern is decided upon, we begin the task of actually laying these tiles where they go more permanently.
The slate is going to be permanently adhered to your sub floor on a cement-based "thinset" mix.
This powder contains Portland cement, ultra-fine grains of silica sand and frequently special powdered acrylic resins for color and for durability.
Once thinset is mixed with water, it makes a sticky mortar that tenaciously grabs onto anything it touches.
The best attribute of thinset is that once dry, it does not flex, and thus you get the benefits of cement.
Once all the tiles are fixed in the thinset, I usually allow it to dry for 36-48 hours before applying the grout filler between the cracks.
At this stage, it is a good idea to think about applying a sealer to the tops of the tiles.
This actually applies a grout-release liquid or better yet, a special wet-look sealer to the slate.
These products will make grouting much easier as grout gets trapped in the rough texture of the slate.
It may take 24 hours for these liquids to fully cure before you can begin to grout.
The final stage is the grouting itself.
The more professional grouters try and keep as little water as possible from gathering in the cracks.
The reason is that water can sit and weaken the structure of the cement.
A nice cake batter of cement is used and spread throughout, then sponged up with heavy sponges, clearing all traces of unwanted cement away.
What results is a clean, finished tiled floor one can be very proud of.