Masonry Magazine August 2001 Page. 22
Water repellents, masonry & mason contractors
by Gary Henry, PROSOCO
Water repellents are commonly specified to protect masonry from water damage. However, they are not a substitute for good design and construction practices. Masonry should be designed and constructed to minimize water penetration. This includes proper flashing, joint design, and detailing.
Water repellents can be used to reduce the amount of water that enters the masonry, but they will not stop all water penetration. If water does penetrate the masonry, it must be able to escape. Water repellents should be breathable, allowing water vapor to escape from the masonry.
Mason contractors should be knowledgeable about water repellents and their proper application. They should also be able to identify potential problems with the masonry that could lead to water damage.
Concrete Masonry Walls
Concrete masonry walls are strong, durable, and fire-resistant. They can be used for a variety of applications, including load-bearing walls, non-load-bearing walls, and partitions.
Concrete masonry walls are typically constructed using concrete masonry units (CMUs). CMUs are available in a variety of sizes and shapes. They are typically laid in a running bond pattern, with the joints staggered.
Concrete masonry walls can be reinforced with steel reinforcing bars. Reinforcement can be used to increase the strength of the wall and to resist cracking.
Concrete masonry walls should be properly detailed to prevent water penetration. This includes proper flashing, joint design, and detailing.
Mortar Analysis
Mortar analysis is a process of determining the composition of mortar. This information can be used to identify the type of mortar used in a building or structure. It can also be used to assess the condition of the mortar and to determine if it is compatible with other materials.
Mortar analysis typically involves taking a sample of mortar and sending it to a laboratory for testing. The laboratory will perform a variety of tests to determine the composition of the mortar. These tests may include:
* Petrographic analysis
* Chemical analysis
* X-ray diffraction analysis
The results of the mortar analysis can be used to identify the type of mortar used in the building or structure. This information can be used to select the appropriate repair mortar. It can also be used to assess the condition of the mortar and to determine if it is compatible with other materials.
Mortar Deterioration
Mortar deterioration is a common problem in masonry structures. It can be caused by a variety of factors, including:
* Water penetration
* Freeze-thaw cycles
* Chemical attack
* Biological growth
Mortar deterioration can lead to a variety of problems, including:
* Cracking
* Spalling
* Loss of bond
* Water penetration
Mortar deterioration can be prevented by using proper design and construction practices. This includes proper flashing, joint design, and detailing. It also includes using a mortar that is compatible with the masonry units.
Tuckpointing
Tuckpointing is the process of removing deteriorated mortar from masonry joints and replacing it with new mortar. Tuckpointing is typically done to improve the appearance of the masonry and to prevent water penetration.
Tuckpointing should be done by a qualified mason contractor. The contractor should be knowledgeable about the different types of mortar and their proper application. They should also be able to identify potential problems with the masonry that could lead to water damage.
The tuckpointing process typically involves the following steps:
1. Removing the deteriorated mortar
2. Cleaning the joints
3. Applying new mortar
4. Tooling the joints
The new mortar should be compatible with the existing masonry units. It should also be properly cured to ensure that it is strong and durable.