PerkGrout How-To Pictorial

The flagstone should be set well to begin with. The base should be at least 3" (more in colder climates) of compacted base rock or appropriate fines material. The joints should be cleaned out to a 2" depth from the top of the stone.

The joints should be at least 1/2" wide (there is no maximum width). The flagstone area should be saturated the day before installing PerkGrout Flagstone Grout.

Add exactly 1 quart (32 fl oz) of water to one bag of Pervious Flagstone Grout. Please use the container provided and fill all the way to the top. Add approximately half bag of contents to a bucket and then add the entire amount of water. Mix briefly with a grout paddle on an electric drill. This is a stiff mix so preferably a mortar-type mixer, one that scrapes the sides can be used.

Note: If rain or freezing temperatures are expected within 24 hours, do not install Pervious Flagstone Grout.

Slowly add the remaining contents of the bag. Mix thoroughly for 2 to 4 minutes or until all the contents have been moistened. This mix should be kept in the shade and will periodically need to be briefly misted with a spray bottle & remixed. When kept in the shade in 70 degree weather, this mix will last about 1 hour.

Using a gauging trowel scoop the grout right out of the mixing tray and into the joints. Have a piece of filter fabric, rag or sponge handy to periodically clean the trowel.

Tamp the grout into the bottom of the joint using the side of the trowel.

Overfill the joint somewhate with the grout. Don't worry too much about spillage. It's usually best to wait a bit, to let loose crumbs dry and then sweep them away. Any residual color stains left on the stone can be cleaned up using a sponge with clean water, being careful not to get water on or disturb the joing itself.

Using the bottom of the trowel smooth down the joint, while applying pressure.

For narrower joints or for a more refined finish, use the grout pointer.

Ends in the sun or that will be left for longer than 15 minutes, should be periodically lightly misted with a spray bottle (adjusted to mist only).

Optional: A day or two later a margin trowel can be used to scrape any remaining loose grout or color stains off of the flagstone.

After 24 hours or more, sweep away the remaining loose rocks and enjoy your patio!