Building and Maintenance Tips: Patios
The outside living season is short in New England, so it’s important to make the most of it. Follow these five maintenance tips to extend the life of your patio and ensure it lasts for years to come.
When building a flagstone patio on a sand bed, you can make it hold up better over the years if you use large, thick stones with flat tops and bottoms and relatively square edges. Large stones resist shifting more than small ones. They’re also less time-consuming to lay and grout.
In constructing a flagstone patio to last, be generous with the mortar joints. Make them at least one inch wide and deep. Thin, shallow mortar joints tend to break up after a few seasons of expansion and contraction, while the mass and surface area of larger joints increase their longevity.
Mortar joints are likely to fail in a short time on a brick patio laid on a sand base. You’ll have better luck-and looks-with a sand-mortar fill. Combine one part cement and four parts sand in a dry mix, then pack all joints around the brick (start with a push broom, then follow up with a trowel). Moisten the grout with a light misting from a garden hose for half an hour. Repeat the misting every day or so for several days to keep the patio damp and allow the grout to bond and cure. Keep the spray light, and be careful not to wash away the grout. Regrout the patio at the beginning of each year or as needed.
Where a flagstone patio meets the house, you’ll often have a major joint that will inevitably expand and contract as the two surfaces move. When caulking large joints like these, fill most of the joint first with plastic backer rods-spongy caulking “noodles” sold at lumberyards. Pack the rods in the gap almost to the top, leaving a little less than the distance across the gap unfilled. Then caulk the rest of the way with sealant. Using this method saves sealant and produces a limber, hourglass-shaped seal that will flex with both materials. Don’t succumb to the expedient solution of filling the cavity with sealant. You’ll not only consume a lot of sealant, but you’ll also get a big, inflexible band that will soon pull away from one side of the joint and defeat its purpose.
In the winter, use sand or cinders to cope with the ice on your masonry patio. Avoid using rock salt, calcium chloride and other salt-based ice-melting products. Salt is a natural enemy of all masonry, as it deteriorates cement mortar and concrete.