Efflorescence and How It Affects Siding
by Amy Lindholm, June 9, 2016
Efflorescence is a fact of life with most types of concrete, stucco and masonry. Each of these materials is very porous and will absorb any moisture they come in contact with. Efflorescence has been a problem for fiber cement siding manufacturers for many years. Unlike fiber cement, engineered wood siding will not effloresce.
On a home, efflorescence occurs when fiber cement siding absorbs moisture – whether from being uncovered prior to installation or from excess moisture entering through the back side of the substrate. Once inside, the water dissolves salts and other minerals in the substrate. When siding is heated by the sun, that water is slowly drawn out and the salts are carried to the surface. As the moisture evaporates, the salts are left behind as a powdery white substance on the surface of siding.
Removal of Efflorescence
The white salt deposits caused by efflorescence do not affect the structural performance of siding, but they can seriously detract from its aesthetic appeal. Removal of efflorescence is time-consuming and labor-intensive. Manufacturers recommend pressure-washing or an acid wash applied to the surface of the siding to dissolve the mineral deposits. However, care must be taken when using acid products, and in some cases it may be necessary to repeat the process to completely remove the efflorescence.
Engineered Wood Siding Does Not Effloresce
LP® SmartSide® engineered wood siding will not effloresce, so you never have to worry about an unsightly residue discoloring the exterior of a home. Unlike fiber cement and vinyl siding, LP SmartSide lap siding also features defining shadow lines and a realistic, deep cedar-grain texture that creates the look of real wood. It’s an excellent choice for homeowners who want beautiful curb appeal and easy maintenance.