Flagstone Preparation

There 3 common ways to install Flagstone... over concrete, commonly called “wet-set”, over a packed base material, and directly on the ground.

Wet Set

For a wet set application, the concrete base needs to be in place, and you apply stone using an exterior thinset material, or a mortar with polymer added to repel water, add flexibility, and achieve superior bonding. Make sure that you follow the control joints that are in the concrete with joints in your stone. This method is usually reserved for the professionals!

Over a Packed Base

To install over a packed base material, the prep work is the most important part of your walkway or patio. First, excavate approx 6” of soil from the area that you are going to apply the stone. Install approx. 5” of crushed Limestone, or a Class 5 gravel, level it off, or screed it to your preferred slope, and tamp with a vibrating tamper. If it is a smaller area, you can also use a 8” or 12” sq hand tamper. This provides a stable and sturdy base for your stone. The next step is to install 1 inch of sand. The best method for this is to get some proper lengths of 1” diameter pipe, pvc or metal, and lay it in parallel to each other, then dump the sand over the area, using the pipes as screed planes. This will produce a consistent thickness of sand. Now you are ready to place the Flagstone. Most folks will want consistent joint widths, so you will usually need chisels and a saw or grinder to cut the stones to fit. Once the stones are laid as desired, use a dead blow hammer to tamp the stones so that they are solidly set into the sand. Sometimes there is clefting on the stones that will either have to be removed, or sand will have to be added or removed to accommodate the difference in thicknesses of stone. A thicker stone will need less sand under it, and a thinner stone will need more sand under it to make the tops of the stone level. Once you have the stones in place and secure, sweep the excess sand from between the stone, and make sure the stones are dry. Sweep in the “Gator Dust”. This is a sand either Gray or Tan, that has a polymer added to it. Make sure you sweep all of the excess Gator Dust off of the stone, and full the joints. Apply a “rain” or mist of water, allowing water to fall onto the entire patio. Make sure you don’t spray directly onto the joints, because this will allow the polymer sand to get sprayed out of the joints and onto the surface of the stones. This is a bonding type of sand, and it will stick to the stones surface if allowed to dry. It will not come off very easy. Allow it to dry for about 3 days, and you will have a patio that is very solid, almost like concrete! The polymer that is in the sand binds the stones together, yet stays flexible to allow for frost heaves in the winter. If more sand is needed, it can be added anytime later, and it will bond together.

Directly Applied Stones

This application is the simplest way to achieve a walkway with minimal prep. It can be installed either before grass is growing, or over an existing lawn. Simply lay the stone where you want it, use a spade to trace around it, then dig the sod out the same thickness of the stone. Sometimes a small amount of sand can be laid onto the ground so you can make it a solid seat. Once this stone is set, its done! Place the next stone in the desired location, and repeat for each stone. Then you can plant grass around and between, or if you have grass there already, the walkway or path looks like it has been there for years! This application is also nice because you can mow right over the stone, since the top of the stone is level with the ground!

Printer Friendly Version

For more information about any of our products call us at:
Phone: 218-525-6360 - Fax: 218-525-6361
E-mail us at: info@greatlakesstone.com
Great Lakes Stone Supply Inc. - 5156 Rice Lake Road - Duluth, MN 55803

Leave a Comment

Your email address will not be published. Required fields are marked *