Have you ever wondered what causes deterioration of brick mortar joints sometimes seen on older buildings? Deterioration to the point that it literally falls out like powdery sand.
The likely cause of damage is damp rising and salt damage.
“Damp Rising occurs when salt laden water is drawn upward into masonry via the capillary action of the porous properties of masonry,” says Peter M. Loy, President of Citadel Enterprises. “Costs to diagnose and make repairs to this phenomenon can be high. The ugly reality is that limited repairs are unlikely to sustain and are rarely guaranteed.”
As a result from rising sea levels, Lowcountry property owners are witnessing more frequent flooding and significant storm events. What follows is soil saturation compounded by salt water infused ground water. Salt crystallization, humidity, evaporation of ground and surface water, air temperatures & flow, and capillary action all play sinister roles in the situation. There are a plethora of exacerbating factors to consider; site drainage, water run-off from roofs, roof gutters, and other impervious features. Additional factors are yard irrigation, proximity to bodies of salt water, proximity to storm drains, HVAC issues (both in the crawlspace and inside the structure). Conditions inside the building envelope often exacerbates the problem. A fact that some people don’t consider is that all natural water contains some amount of salt.
Deterioration to masonry piers, chimney foundations, perimeter walls, and brick veneer can appear in the form of brick mortar falling out. The saline content in masonry can cause a white powdery appearance often referred to as salt efflorescence. Damage can also be seen in interior finishes such as plaster, drywall, wood trim, marble & stone, and paint coatings.
“It is actually a pretty creepy sight to behold,” Loy says. “I have personally witnessed degradation so advanced that it compromised the structural stability of buildings.”
“What’s the point in making repairs only to have to deal with more repairs later on?” Loy says. “Making repairs for the long term is a better strategy and investment for your money.”
The centerpiece for the repair procedure is the creation of a barrier between the moist soil and the imbedded masonry structure. This barrier acts as a damp proof course or DPC. The next step is to remove the permeated salts, a process referred to as de-salinization. Both the DPC and desalinization procedures are easier said than done.
A damp proof barrier can be achieved by applying water resistant chemical solutions into the cavities of the foundations. It is difficult to observe the completeness of the application and doesn’t lend itself well for repeat applications. The approach Loy recommends is the insertion of rigid or stainless steel metal plates in conjunction with seismic restraints. Loy continues that both approaches, use of liquid chemical and sheet steel are best left to experienced professionals. It is hard work in nasty conditions and often involves sophisticated masonry cutting tools that are water cooled with a diamond blade.
Removal of salts entails the application of a poultice. A poultice is typically a mixture of lime, sand, water, and shredded paper. Commercial products are available but not always readily attainable. De-salinization requires patience with multiple application over several weeks or even months to achieve suitable result. Upon satisfactory results from the desalinization process then restoration of damaged materials can commence. As a side note, before starting repairs of this nature on historic properties be sure to coordinate with the government agencies and related authorities.
Mr. Eric Doehne of Conservation Sciences, and Mr. Kirk Edmonds, P.E. contributed to this article.
As a Lowcountry leader in affordable home repair services, Citadel Enterprises, Inc. can offer professional, experienced craftsmen for your bathroom and kitchen remodeling, additions, outdoor living, and more. Please contact them at (843)884-4303 or visit citadelenterprises.com.