Efflorescence is the gift that keeps on giving. Like pyrites to precast, efflorescence is an unsightly condition that can ruin the appearance of your masonry structure or even damage it to the point of repair. What causes efflorescence? A recent article published in July 2019 Masonry Magazine takes an in depth look at the issue at hand, the following is a excerpt from that article, the full article can be accessed by members of Mason Contractors Association of America.
Thermal changes and ground settlement are some of the reasons concrete surfaces crack. This is inevitable with all types of concrete and concrete surfaces, ranging from smooth and split-face concrete block to poured-in-place, precast, and tilt-up walls.
Overlay: When Is It Appropriate?
Leaving existing joint sealant in place and installing an overlay of new sealant can be an option if the conditions allow. While this could be considered a cost saving technique, the majority of existing conditions would not be acceptable for this technique. While it would save the installer time, in addition to material, by not removing the existing sealant, it mostly results in improper joint design and extremely premature failing of system.
THE SIGNIFICANCE OF THE INITIAL RATE OF ABSORPTION IN BRICK MASONRY WALLS
Masonry mortar must bond well to the masonry units in the wall. Brick absorption, including initial rate of absorption (IRA), is an important property affecting the bond. IRA also is a property for which a standard test method exists.
It's not every day that we see both an adhesive and cohesive sealant failure at the same location:
Improper joint design, poor material mixing, incorrect sealant selection, sub-par preparation; all leading causes of premature joint failure. The example shown below is a very uncommon example of joint failure.