How To Lay Flagstone Over Existing Concrete Patio

How to Lay Flagstone Over Existing Concrete Patio

Laying flagstone over an existing concrete patio is a great way to add a natural and elegant look to your outdoor space. While it may seem like a daunting task, it's actually a relatively straightforward project that can be completed in a few days with the right materials and tools.

Materials You'll Need

Flagstone: Choose flagstone that is appropriate for the size and style of your patio. It should be at least 2 inches thick to ensure durability.
Concrete backer board: This will provide a stable base for the flagstone.
Mortar: Use a mortar specifically designed for outdoor use.
Polymer-modified thinset: This will help to adhere the flagstone to the backer board.
Grout: Use a grout that matches the color of the flagstone and that is designed for outdoor use.
Jointing sand: This will be used to fill the joints between the flagstone.
Level: Use a level to ensure that the flagstone is laid evenly.
Tape measure: Use a tape measure to measure and mark the location of the flagstone.
Chalk line: Use a chalk line to snap a line where the flagstone will be laid.
Trowel: Use a trowel to spread the mortar and grout.
Bucket: Use a bucket to mix the mortar and grout.
Sponge: Use a sponge to clean up any excess mortar or grout.

Steps to Lay Flagstone Over Concrete Patio

Prepare the concrete patio. Clean the concrete patio thoroughly and remove any debris or dirt. Fill any cracks or holes in the concrete with concrete patch.
Lay the concrete backer board. Cut the concrete backer board to fit the size of the patio and lay it over the concrete. Secure the backer board with concrete screws.
Mix the polymer-modified thinset. Follow the manufacturer's instructions for mixing the thinset. Apply a thin layer of thinset to the backer board with a trowel.
Lay the flagstone. Start laying the flagstone in the corner of the patio and work your way out. Use a level to make sure that the flagstone is laid evenly. Press the flagstone into the thinset until it is level with the surrounding flagstone.
Grout the flagstone. Mix the grout according to the manufacturer's instructions and apply it to the joints between the flagstone. Use a trowel to spread the grout and press it into the joints. Remove any excess grout with a sponge.
Fill the joints with jointing sand. Apply jointing sand to the joints between the flagstone. Use a stiff brush to work the sand into the joints and remove any excess.
Seal the flagstone. Apply a sealer to the flagstone to protect it from stains and moisture. Follow the manufacturer's instructions for applying the sealer.