Rocha Construction, LLC

You dream it, we build it!

Hardscape Patio


Flagstone (also known as Slate) is a really popular type of material that can be used to create gorgeous stone patios.

As a Stone Patio Contractor, we can offer you two main install procedures, both of them have pros and cons, but when done right, the result is a professional looking patio that is long lasting.

Here are a few pointers on what to look for when working on having a flagstone patio installed.

- Flagstone Patio on a Concrete Base:

Flagstone Patio These patios are the most populars in the area. The idea is to install the stone on top of a reinforced concrete base. This procedure ensures that the flagstone will not sink or move with time, leaving you with a patio that will last for years to come.

For this procedure is always recommended to have a concrete base that is at least 4" thick and reinforced with fiberglass or welded wire mesh. This structure should be installed on top of compacted soil, or layer compacted gravel bed to add support to the whole structure.

After the concrete is installed, the stone comes next. We recomend that you request the stone contractor to install at least 1" to 1.5" thick slate pieces. The thinner the pieces, the more brittle they become with time.

Stone Patio Many contractors might cheat you into thinking that 1" thick concrete or 0.5" thick flagstone would be enough. (so they can give you a cheaper estimate). It is up to you... but do not expect the patio to last many years if the material is lacking quality from the beginning.

- Flagstone Patio on Stone Dust / CR6:

Irregular Flagstone Patio These slate patios are more economical and faster to build than the ones in concrete. They also have the advantage of being able to be repaired at a much lower cost.
Any damaged or sunk stone could be replaced in just minutes for a new piece, saving you hundred of dollars in the process.
The only downside is that its more difficult to keep looking perfect due to weeds and settlement.

Irregular Stone Patio To install this flagstone patio, the stone contractor starts with a 4" base made out of compacted gravel with stone dust (called CR6 in our area). This material is easily compactable and gives us a very strong surface.

We will need thicker flagstone pieces for this slate patio. Since we do not have a concrete base, the thicker and heavier the stone, the more stable it will be down the road.
After having a leveled and compacted base, we finally cut and place the stones on the ground and fill the joints with more stone dust for support.

If you are not a fan of weeds between the stones, a layer of "weed stopper" or "geotextile" barrier under the gravel bed can be installed.

This is a broad overview of how we install our flagstone patios. There are more procedures that other stone contractor might use. But I hope that the information given will help you make the best choice for your house. If you need a professional contractor to install or just help you with your slate patio, gives us a call. We offer free estimates for all Montgomery County and Maryland!!

Rocha Construction: (301) 717-8310


It is NOT allowed to use our pictures without our written consent.

It is NOT allowed to use our pictures without our written consent.

Rocha Construction, LLC
(301) 717-8310
MHIC: 96026
Now installing patios and stone work on the areas of: Bethesda, Potomac, Chevy Chase, Rockville, Silver Spring, Gaithersburg, Germantown, Olney, Montgomery Village, Wheaton, Kensington, and many more in Montgomery County and Maryland!