Brick is beautiful. It’s strong, weather-resistant and durable. So durable, in fact, that ancient structures made from mud bricks almost 10,000 years ago have been found throughout the Middle East. In spite of its durability, though, masonry – brick and the mortar that holds it in place – must be maintained to ensure that it provides protection from the elements, preserves its structural integrity and remains aesthetically pleasing. Masonry restoration also plays an important role in protecting or enhancing the value of a property. Brick is compromised over time as moisture enters the structure. If this continues without being addressed, it will lead to substantial structural damage and require replacement. The cost of replacement will be much higher than if the masonry were properly maintained.
Over time, masonry may need to be cleaned, pointed, sealed or even replaced. The brick itself may still be strong, but the mortar that holds the bricks in place will need to be pointed, which requires using mechanical grinding to strip away and replace some of the mortar. The primary purpose of pointing is usually waterproofing. Pointing also helps retain the structural integrity of the masonry, but if the integrity of a structure is already weak, pointing will not help.
Determining the mortar to use when pointing is especially important, as it should match the existing mortar color and joint profile. The joint is the area between bricks where mortar is placed. Mortar consists of sand, lime and cement; the formulation used will determine how hard the mortar is when dry. In pre-World War II structures, lime mortar was used with little if any Portland cement in the mix. Since then, a harder mortar with less lime has been used, but more recently the trend has been to use a softer mortar, which provides a better seal against the elements.
Pointing is an important step for protecting a building, but it is often necessary to take other steps. Installation of thru-wall flashing may also be needed to stop moisture penetration. If there are bowed or unsound areas, they need to be selectively rebuilt, or demolished and replaced. Lintel and relief plates may also need treatment or replacement; a lintel is a horizontal support of timber, stone, concrete or steel across the top of a door or window.
There is an art to masonry restoration. It’s important to retain a qualified contractor with a good reputation to avoid irreparable damage to your masonry. While pressure-washing can be used to clean brick, for example, if the brick is old and in poor condition, pressure-washing may cause damage. Chemicals or abrasives are also used to clean brick, but either can cause damage in the wrong hands. Depending on the location and condition of your property, an application of a clear masonry sealer can help prevent moisture penetration.
Regulations must also be considered. The means and method of construction have to comply with the state building code, and federal regulations issued by OSHA and the EPA. While a building may be grandfathered in and not have to comply with current building standards, coming up to code may be necessary as a safety precaution or if a building is being renovated. Bringing an older building up to code can be expensive. For example, while New England isn’t known for its earthquakes, building codes require that masonry conforms to seismic standards detailed in the Code of MA Regulations (CMR), Chapter 21.
Among other things, the law says, “Masonry walls shall be anchored to the roof and all floors that provide lateral support out of plane for the wall. The anchorage shall provide a direct connection between the walls and the floor or roof construction. The connections shall be capable of resisting the greater of the seismic lateral force induced by the wall or 120 pounds per lineal foot of wall (allowable stress design), or 200 pounds per lineal foot of wall (strength design).”
Retrofitting a masonry building to meet these standards may require that all floors and roof lines be tied to the masonry, and that the sheer of the roof and some floors be changed.
During masonry restoration, structural engineering specifications, aesthetics and the integrity of the building all need to be considered. It takes knowledgeable, experienced craftsmen to address all of the issues necessary for a successful restoration project.
Kieran Fitzgibbon is co-owner of Statewide RM, Brighton, Mass.