How to Weather Proof Your Flagstone Patio

What You'll Need
Weatherproof membrane
Flagstone sealer
Quick-set sand

A flagstone patio is a beautiful and expensive place where you can enjoy many hours of free time with friends and family. The flagstone patio is able to house anything from deck furniture and a fire pit to a grill. Flagstone is a natural stone and because it has not acclimated to its surroundings the color of it can fade instead of remaining vibrant. This is not necessarily your fault but that of the environment and the elements. If you were to install flagstone to a kitchen floor or on a mantle the color of the flagstone will remain consistent. This is because the environmental conditions are standard. With a flagstone patio it will be bombarded with wind, rain, snow, ice and then of course heat. The flagstone does not have time to adjust to any one particular circumstance and so they become discolored. The solution is to weatherproof your flagstone patio and the following article will show you how it is done.

Step 1 – Weatherproof Membrane

If you are installing your flagstone patio from scratch then you most likely used landscaper’s fabric to prevent weeds from growing between or through the flagstones. This is one key step to weatherproofing a flagstone patio. For this you will also want use a weatherproof membrane which resembles rubber with little pockets throughout the surface. The membrane prevents water from entering the site and is instead absorbed by the surrounding ground. The membrane is cut to fit the site and is then placed directly on top of the sand.

Step 2 – Sand

Using mortar to seal the edges of the flagstone patio stones will ruin the overall look of the patio. The traditional way is to use sand to do the job for you because once dry it is compacted and very hard. If you are in an area that gets a lot of rain this may not be practical. The solution is to use a product that is known as a quick-set or mortar sand. It is still sand but is treated with certain additives that when wet it is just like typical sand but when it dries it dries as hard as concrete. You can still work with it in the same manner as typical sand. You pour it over the patio and then broom it into the gaps. You then wet it down and repeat with more sand until the gaps are completely full and dry.

Step 3 – Sealer

To prevent the color of the flagstone from fading you will want to seal it with a special weather coating. It resembles polyurethane but is formulated specifically for flagstones. You can purchase stone sealer with special color enhancing additives added to it. Application of the sealant is as simple as painting a wall. Simply pour the sealant into a paint tray and then use a paintbrush or paint roller to apply at least two layers of sealant to the flagstone patio.