The Best Time to Seal a Concrete Driveway

Frequency

• Sealing a new concrete driveway prevents damage to the surface from occurring. Once the concrete cures for three to four weeks, it is time to seal it. After that, the driveway should be resealed when the sealer begins to show wear or deterioration. This may be within two years or as long as five years. The harshness of the weather conditions, the amount of wear the driveway receives and the type and quality of the sealer used will affect the length of time between sealings.

Weather

• Your driveway can be sealed at any time of year when the air temperature, as well as the surface temperature, is between 50 and 90 degrees Fahrenheit. Concrete sealers cure by evaporation. The warmer the temperature, the quicker the liquid will evaporate and form a hard plastic resin seal. If the temperature is too hot, flash curing will occur, causing spider webbing and bubbles on the surface. If you must seal during the summer, avoid the heat of the day. If the temperature is too cold, a white haze, dusting or delamination of the product may result. The pavement also needs to be dry for proper sealing. Choose a time when the forecast calls for 36 to 48 hours without rain for best results.

Types of Sealers

• The type of sealer will affect the end results. Penetrating sealers permeate the pores of the concrete and harden. The sealer fills the gaps of porous concrete, preventing salt, de-icers and chemical spills from being absorbed by the concrete. Water and harmful substances stay on the surface where they can run off, eliminating excessive wear on the concrete. Penetrating sealers are nonslippery and UV resistant, and they allow moisture within the concrete to evaporate. Film-forming sealers create a barrier on the surface of the concrete, which seals in moisture that may cause blistering. The film wears off over time and needs to be reapplied more often.

Application

• Concrete sealers should be applied to a clean, dry surface. Power washing the driveway helps prepare the surface for sealing. Large cracks and holes in the concrete must be repaired before sealing. Solvent-based sealers can be applied with a sprayer, but water-based sealers are applied with a long-handled roller. Apply two thin coats of the sealer rather than one thick coat for the best results. Maintenance of the surface involves periodic cleaning with soap and water.