Here we answer some of the frequently asked questions about Curb YOUR Nature, landscaping and our products.
Q: Why are there white “spots” on top of my new concrete edging?
A: This white powder is a type of discoloration known as efflorescence. It is a deposit, usually white in color that occasionally develops on the surface of concrete, often just after a structure is completed. Although unattractive, efflorescence is usually harmless. In rare cases excessive efflorescence, within the pores of the material, can cause expansion that may disrupt the surface.
Efflorescence is caused by a combination of circumstances: soluble salts in the material, moisture to dissolve the salts, and vapor transmission or hydrostatic pressure that moves the solution toward the surface. Water in moist, hardened concrete dissolves soluble salts. This salt-water solution migrates to the surface by vapor transmission or hydraulic pressure where the water evaporates, leaving the salt deposit at the surface. Particularly temperature, humidity and wind affect efflorescence. In the summer, even after long periods of rain, moisture evaporates so quickly that comparatively small amounts of salt are brought to the surface.