Masonry Magazine January 2001 Page. 24
MASONRY: Have you noticed
any problems with the actual
concrete masonry unit (cти)?
Hier: No. The drainage problems occur when the concrete masonry unit is untreated. Concrete by nature absorbs water. That being the case, the developer, designer, and the contractor all need to, as a team, make sure that the concrete block is treated with a water repellent, NOT a water sealant.
MASONRY: What is the differ-
ence between water repellent
and water sealant for concrete
masonry units?
Hier: Water sealants actually do more harm than good. Concrete needs to breathe. So when a sealant is applied, the concrete forces the water into the structure rather than allowing it to evaporate outside the structure. This makes the concrete blocks spall, leaving unsightly holes in the exterior of the structure. A water repellent, on the other hand, does not allow water into the cmu, but permits water to evaporate out of the exterior surface without any damage. A potential problem occurs when the developers place a sealant on the wall thinking that this will seal the wall, when actually they are destroying it. Almost all concrete blocks that are sealed will eventually have some water seepage and aesthetic issues.
MASONRY: Do you think there
is a shortage of qualified build-
ing inspectors?
Hier: The key word is "qualified." There are surely enough city and private building inspectors in this area, but very few are properly trained in masonry and masonry detailing. This immediately places the entire masonry system at a disadvantage. Until the general building inspectors in non-West coast areas are properly trained, there will remain a shortage of qualified building inspectors of masonry. Because of the stage in which I enter the construction process, the City's building inspectors have already inspected the site. However, I still see very basic problems in masonry that could have been avoided had the original inspector been properly trained to recognize common masonry detailing issues. Most city building inspectors have little experience with construction, let alone masonry. I am not going to to say that you absolutely need construction experience, but it sure is helpful.
MASONRY: In summary, what
can be done to avoid drainage
problems due to improper
detailing, installation and
inspection of masonry?
Hier: Everyone involved in the project needs to take responsibility for their portion and do things correctly. Responsibility should be divided at pre-construction meetings. Most drainage problems can be avoided if the developer, designer, and building inspector were all properly trained on masonry details. The developers and designers need to make sure that the correct masonry details are specified on the job drawings and specifications, and the contractors need to make sure that they are installing the specified details correctly. Contractors usually know when something is omitted and in those instances, they need to speak up, because ultimately they are the ones who will take most of the blame.
Opportunities and challenges await the industry. With a corps of inspectors lacking the necessary skills needed to inspect masonry construction systems, a more concerted effort must be waged to train these inspectors who inavoidedly can be allied with the masonry industry. Additionally, if the construction boom continues, increased focus must be given to educate both the contractor and the customers to make them more aware of what to look for when choosing a quality mason contractor.
Steve Hier is the President and Owner of Miller-Hier Enterprises, Inc, a home inspection and consulting company. Mr. Hier has a BS in Mechanical Engineering from South Dakota School of Mines and Technology and has worked in a variety of engineering and management positions for US Steel, and US Army Corps of Engineers. He has also owned and operated his own general contracting and home construction company before becoming a home inspector. He is a certified member of the American Society of Home Inspectors (ASHI)