How to Build a Patio in Cold Temperatures

Using Masonry Materials In Cold Weather

• You may be one of the many homeowners who must put off exterior building projects until the cool weather arrives. The seasonal weather changes can cause specific problems with building materials if you are attempting to build a patio with masonry materials in cold temperatures. The cold may require using alternate materials that are not as easily affected by temperatures, as well as mixing mortar in a way that make it less susceptible to early freezing, according to writer Jamie Farny at the Masonry Magazine website.

Concrete Patios

• Installing a concrete patio can be particularly challenging because of the amount of water that concrete possesses normally as one of its ingredients, along with Portland cement, sand and gravel. Concrete should never be poured over frozen ground, according to home improvement expert Tim Carter of the Ask the Builder website. Crystals within the concrete mix that hold the sand and gravel together are broken by the expansion of the water in cold temperatures. The ideal environment would be to place tarps over the excavated area and run heaters to warm the ground. Concrete is best poured when temperatures are above 40 degrees Fahrenheit. After the concrete is poured, a curing compound must be sprayed onto the surface. Then, place insulating blankets over the patio area, which will generate the heat needed to allow the concrete to dry properly.

Paver Patios

• Paver blocks have the advantage of being impervious to the expansion and contraction of changing temperatures. The ground beneath the patio area can experience shifting and heaving during cold temperatures, however, and this can lead to unevenness in the patio surface. Digging down 6 to 8 inches, then laying 2 to 3 inches of aggregate and at least 2 inches of sand helps to keep pavers from shifting. Tamp down the aggregate layer and the sand layer before installing the pavers on top.

Flagstone Patios

• Flagstone patios require mortar that can be affected by cold temperatures. A temperature between the mid-50s during the day and a nighttime low of 40 degrees Fahrenheit is ideal. Temperatures below 28 degrees Fahrenheit for 48 hours or more would cause the delay in drying that creates problems in setting mortar. Crystals needed for the hydration of the material prevents the proper bonding in the cement-based mortar material. To prevent this problem, warm flagstones and mortar before using.