Home Structure Tips
We all hope that the masonry in our home will never need repair. But eventually, it does. Even brick will succumb to aging, and once they show their age, they need help.
Your ability to spot structural damage is important to the overall well-being of your home. Although cracking and bulging are far less common than slight deterioration of mortar joints, such major problems sometimes do appear in an older building
To assess the condition of brick walls, look along the wall to see if any sections are bulging outward. The most common locations are at the bottom of the wall and halfway up, near windows. Bulges in the structural brick walls usually result from failed mortar joints. In a veneer wall ( which is a wood structural wall linked at intervals with metal ties to a covering layer of bricks), bulges can usually be traced to ties that have come loose either from the wood or the bricks.
Although bulges rarely threaten the integrity of the building, the trouble is usually confined to the immediate area, which will need to be addressed in time. The job of eliminating bulges is best left to the professional.
Cracking may be caused by the settling of the soil below the wall. The building may have been constructed on land that was not compacted enough to accommodate the structure. Or the soil may have shifted due to groundwater or other causes and carried one part of the wall with it. Other causes of cracks are rotted ledger(horizontal beam) over the window, cycles of freezing and thawing, and impacts such as from a car. Masonry walls will tolerate a fair amount of movement without posing the danger of collapse or of sections falling out. It takes a lot of movement to cause collapse, but if you are concerned with such issues, call a masonry contractor or engineer for an inspection.
It's important to learn whether a crack has opened to it extreme, indicating that the source of the problem has stopped, or is still opening more, or going through a cycle of opening and closing. Test to see if the crack is stable by filling it with plaster. If there is any movement, the crack will reappear in the brittle plaster. Watch for several months, and check every few weeks; the crack may open and close.
If the crack continues to open, even a small fraction of an inch over several months. the structural problem must be resolved before the wall suffers increased damage. Consult a professional.
If you are sure that the crack is neither growing nor oscillating, fill it with grout, a thin mixture of non-shrinking mortar. Clean all loose mortar out of the crack. Use a small, specialized masonry chisel to undercut the surface of the crack so that the interior portion is wider than the portion of the surface, the grout will adhere better that way.
Next, wet the crack. Brace a 3-ft long board against the lower part of the crack and use a funnel to pour in the grout. Work up the crack with additional boards, if necessary. Remove the board once the grout has set, then scrape away any excess mortar then re-point the length of the crack.
Cracks around windows and doors may not be caused by soil settling but by shrinking and expanding of the wooden framing of the door or window due to the changes in moisture content. This shrinking and expansion may still be going on, so using mortar in these areas may be a losing proposition. A better bet is to fill the cracks with a silicone caulk, which will flex with movements of the framing, eliminating the crack.