Efflorescence is a wonderful-sounding word that unfortunately refers to a basement issue that can be a real nuisance. Literally meaning "to flower out" in French, efflorescence is the crusty, white discolouration that can form on the inside or outside of a basement constructed of concrete or masonry brick. Depending on when the foundation of the home was constructed and when the efflorescence was discovered, it can either be relatively harmless or an indication of a more serious problem.
Most commonly, efflorescence is crystallized salt from within the composition of the concrete or masonry, or from the earth surrounding the foundation and underneath the base plate. Occasionally, depending on the composition of the concrete, it can be composed of calcium hydroxide, or lime. A number of factors need to combine in order for efflorescence to occur:
If the surrounding air contains low humidity, the seeping salt mixture may dry before pressure pushes it to the surface of the concrete. If higher humidity is present, the salt will squeeze to the surface, where the air will evaporate the moisture and leave crystallized efflorescence deposits.
It is usually detected in the later winter and spring, when moisture build-up is at its peak. In newer structures, efflorescence can occur naturally after the new concrete or masonry has been exposed to earth and groundwater for a short period of time, and, while unsightly, it may not be indicative of a larger problem. In older buildings, it can be a sign of foundation materials that are structurally compromised and/or inadequate drainage features around the structure, especially if the efflorescence reoccurs after an initial clean up. It is cases like this that require experienced London basement repair. Chronic efflorescence where the source of the problem is left untreated can cause the building material to peel or flake on the surface, and eventually cause crumbling and deterioration.
If addressed soon after it appears, removing the crystallization from the walls or floor could be as easy as pressure washing the area to dissolve the stains, rinsing with fresh water, and thoroughly drying the area with a wet vacuum or air jets.
In larger occurrences or if allowed to form for some time before being treated, further chemical reaction to the surrounding air can render the stains insoluble, which makes clean-up a lot more difficult. Wet basement repair professionals may use mild to heavy acid treatments to dissolve the efflorescence, depending on the severity, the handling of which can be very dangerous and not recommended for the average homeowner.
A reoccurring problem must be addressed by attacking the causes of excess moisture. Exterior drainage methods, such as downspouts, soil grading and weeping tile around the structure should be examined and altered to direct water away from the foundation. Less visible causes, such as water that is wicked up through the sub-grade from the groundwater can be prevented using vapour barriers and by coating the floor with a special sealant to prevent moisture from reaching the surface.
While efflorescence itself isn't necessarily a serious issue, it can be a sign of bigger problems down the road. Contact the London wet basement repair experts at BEST for advice if you think you have a problem with efflorescence, and we will not only help you remove it, but also prevent it from happening to your home again.