Curing Process for Stucco Finish

Normal Curing

• When conditions permit normal, non-induced curing, moisten the brown coat before adding the stucco coat. Lightly pre-wet the brown coat by hand and allow sufficient time for the water to be absorbed into the brown coat before applying the stucco coat. Curing will take place as absorbed water migrates from the brown coat into the stucco coat. The stucco coat also absorbs water from the atmosphere.

When To Induce Curing

• Curing should be induced when conditions are not favorable for natural curing. These include air temperature above 90 degrees, relative humidity below 70 percent, and conditions of wind and direct sunlight that accelerate premature drying of the stucco coat.

Induced Curing

• Induce curing by lightly moistening the brown coat before applying stucco. Allow sufficient time for the water to be absorbed into the brown coat before applying the stucco coat. Allow the applied stucco coat to set overnight, then mist lightly with water once or twice a day for at least the next two days. For the next seven days, occasional misting or fogging may be necessary to maintain moisture content as the stucco cures, according to the external conditions of temperature and humidity.

Colored Stucco

• If the stucco coat includes coloring, misting may cause discoloration, so water is not applied. Colored stucco coats are cured by wetting the brown coat with sufficient water to allow full curing to take place from underneath. To retard evaporation in conditions that do not favor natural curing, colored stucco may be covered with sheets of polyethylene to retain moisture.