Slate Floor Cleaning Houston


Houston Slate Cleaning:

Due to the texture and graininess of this particular stone, a good amount of dirt can build up in its crevices. Generally, we will clean slate with an alkaline cleaning solution because it is the best at emulsifying dirt. We give the solution approximately 20 minutes of dwell time. This gives the cleaner time to depolarize the dirt that is embedded into the stone. We then use an industry accepted spinner tool which provides pressure coupled with vacuum for extraction.

This process also removes dirt from the top of your grout lines. If necessary, depending on the grout, we will use the same method with an acidic solution in order to etch the grout lines back to their original color. This is the industry recommended method to clean non-calcareous based natural stone and tile floors. We recommend cleaning slate at least annually, and as often as bi-annually.

Houston Slate Sealing:

Generally speaking, slate has a low porosity rate. This means that it does not really absorb liquid. Unfortunately, not all mercantile slate is actually slate. For this reason, we recommend sealing your mercantile slate. We generally use a premium repellent with color enhancing properties on slate. This leaves the stone with a wet look, but not glossy. There are other sealers that we can use on this stone also, depending on the finish that the customer is looking for. Slate in a shower or around a pool must be sealed. Call for details on any of our services or fill out the contact form on this page.



Shale is a clay stone that is fissile, or splitting in layers. Slate is a low-grade metamorphic rock which begins as shale. When shale is put under pressure, and has temperatures of a few hundred degrees, the clay begins to revert back to the mica minerals from which they formed. This process hardens the shale and gives it the slatey cleavage foliation which allows it to be split into flat planes.

Slate is typically green in color due to its chlorite content, but can be gray or black if organic matter is present. It can also be red, purple, or brown with a high content of iron oxides. Slate with high iron oxides are poor for wet environments such as showers or pool surrounds, due to the fact that moisture will cause further oxidation of the iron, and eventually degradation of the stone itself. Sealing slate in these environments is imperative, and will prolong the life of the stone. Through further metamorphism, slate becomes phyllite and eventually either schist, or gneiss, which is used as mercantile granite countertops.

Shale is often sold as slate by lower quality flooring retailers and some big box home improvement stores. When wet, shale will smell like clay, and actually lose some of its color when wiped with a rag. It will also make a dull “thud” when tapped with a hammer. Slate will not smell like clay when wet, and will “ting” when tapped with a hammer. True slate is one of the least absorbent stones on earth while shale will have a high porosity.


Mercantile slate is a stone with directional cleavage. Anytime you have foliation of a stone, dirt will become trapped in the lower levels on the surface of the stone. For this reason, slate floors require a maintenance plan to keep them looking as nice as possible. This should consist of dry dust mopping daily using a clean rayon mop or static pad. Vacuuming with a hard surface vacuum will also work. This is to remove the dirt and debris that accumulates on your floor because of foot traffic, pets etc.

It is important to remove this dirt because damp mopping is also required at least weekly. If the dirt and debris that accumulates is allowed to remain on the floor, when damp mopping occurs, that dirt is turned into mud and is pushed into the grout lines by the mop. This will make your grout lines dirty very fast. When damp mopping with soap, rinsing will be required. After mopping with any soap solution, use a different rinse mop, and go over the area again with clean water. We recommend cleaning slate at least annually and in some cases, bi-annually.