Masonry Cleaning and Waterproofing
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How often should masonry surfaces be waterproofed?
Masonry (e.g. Brick, Stone, Concrete, Stucco) Cleaning and Waterproofing
1. What’s that “white stuff” on my brickwork or stonework?
It’s called “efflorescence” or what is known as water
soluble salts. There are two kinds of efflorescence, primary and secondary... some people also call these powdery or crystalline efflorescence.
Primary efflorescence is named such as it typically occurs
during the initial cure of a cementitious product. It routinely occurs in
masonry construction, particularly brick, as well as some firestop mortars.
Water moving through a wall or other structure, or water being driven out as a result
of the heat of hydration as cement stone is being formed, brings salts to the
surface that are not commonly bound as part of the cement stone. As the water
evaporates, it leaves the salt behind, which forms a white, fluffy deposit, that
can normally be brushed off. Since primary efflorescence brings out salts that
are not ordinarily part of the cement stone, it is not a structural, but,
rather, an aesthetic concern. As we said above, primary efflorescence is common on the initial cure of new masonry construction.
Secondary efflorescence is named such as it does not occur
as a result of the forming of the cement stone or its accompanying hydration
products. Rather, it is usually due to the external influence of concrete
poisons, such as chlorides or other salts. Secondary efflorescence is akin to
osteoporosis of the concrete. Typically, secondary efflorescence results in a hard or crystalline like encrustation on a surface. Something should be done to correct the cause of such efflorescence.
Efflorescence can often be removed using phosphoric or other acids. After
application, the acid is neutralized with mild soap detergents, and then well
rinsed with water. However, if the source of the water penetration is not
addressed, efflorescence may reappear. It is absolutely imperative to address water infiltration issues if you have efflorescence problems.
2. What is masonry water proofing?
Masonry waterproofing is the application of hydro-phobic (water hating) sealers to protect masonry building materials such as brick, tiles, stucco, concrete and pavers against efflorescence. The sealers are designed to repel water and will penetrate deeply enough into the masonry material to keep water and dissolved salts well away from the surface.
3. How do I know I should have my masonry waterproofed and what products applied during masonry waterproofing?
Most new buildings constructed today with masonry surfaces
are not waterproofed by the building contractor. The easiest way to
determine if you building requires waterproofing is to simply spray a hose on
the building after it has been dry for a couple of days. If the surface
absorbs the water and changes color, the masonry surface will benefit from
waterproofing. Absorption times for various surfaces vary... from as little as a couple of seconds (high absorption) to 15 minutes or more (slow absorption).
Generally speaking, the products which are applied for
waterproofing contain silicone. They cause no change in appearance of most
surfaces once dry, but in some cases tend to darken the surface one “shade” or
so. The concentration of the silicone can range from 5% to 20%.
4. Can you get vines off my brickwork or stonework?
Vines and their associated “feet” can usually be removed completely from stone or brickwork, provided the stone or brickwork is of a sufficient hardness. Vines situated on soft stones, such as sandstones or soft faced bricks may not be removed in their entirety without damage to the surface.
5. I am re-pointing my masonry, how can power washing help me?
Power washing can save you hours of labor over hand removal of failed masonry joints. We have specialized nozzles which are very aggressive on surfaces that can be used to follow the existing masonry joints to remove loose or failing mortar material quite efficiently.
6. How often should masonry surfaces be waterproofed?
Typically, a 5 to 15 year lifespan can be expected after application of masonry waterproofing products.