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 of rising sea levels, Lowcountry property owners witness more frequent ﬂooding and signiﬁcant storm events. What follows is soil saturation compounded by saltwater infused groundwater. Salt crystallization, humidity, evaporation of ground and surface water, air temperatures & ﬂow, and capillary action all play sinister roles in the situation. Many exacerbating factors consider; site drainage, water run-oﬀ from roofs, roof gutters, and other impervious features. Additional factors are yard irrigation, proximity to saltwater bodies, proximity to storm drains, and HVAC issues (both in the crawlspace and inside the structure). Conditions inside the building envelope often exacerbate the problem. The 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 repair procedure’s centerpiece is creating a barrier between the moist soil and the embedded 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 desalinization. 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 application’s completeness 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, 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 applications over several weeks or even months to achieve suitable
results. Upon satisfactory results from the desalinization process, then the 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 remodeling and kitchen remodeling, additions, outdoor living, and more. Please contact them at (843)884-4303 or visit citadelenterprises.com.