Five Mistakes To Avoid With Old Masonry
Old exterior masonry has a beauty and character all of its own, so you want to make sure it stays in good repair. Knowing what to avoid is just as important as knowing what to do when it comes to older brickwork.
1. Repairing With the Wrong Mortar
Older bricks are typically not fired to the same standards as modern bricks, plus the materials used were often softer and more porous. For this reason, lime mortars were often used to build the masonry because it has a complementary porosity and hardness to the bricks. Modern mortars are much less porous and soft, which can put stress on the brickwork and increase the chances of cracks because there is less flex between the materials. Always match the mortar to the brick type.
2. Installing Corrosive Metals on Brick
Metal is often attached directly to brick, whether it is a drainage pipe routed through a brick retaining wall or a stair banister bolted to the home's exterior. If the metal begins to rust and corrode, it can actually swell and begin to break apart the brick or mortar it is passing through. Use non-corrosive galvanized bolts and metals for any piece that is in contact with brick. Alternative materials, like a PVC drain pipe, are also recommended.
3. Plugging the Weep Holes
Weep holes are holes drilled through bricks or mortar to allow moisture to drain out of the masonry. They may be paired with metal flashing that routes the drainage away from the bricks. Sometimes these holes are mistaken for damage and they end up patched over. This will trap water in the brick and increase the chances of mortar decay, cracking, and efflorescence stains. Don't patch holes unless you are sure they aren't weep holes.
4. DIY Patches Instead of Repairs
It can be tempting to quickly fix some crumbling mortar or a chip in a brick by patching it with a small amount of caulk or mortar mix. Unfortunately, this may improve the cosmetic look of the brick, but it may lead to further damage later as moisture seeps into the weak repair and cracks the mortar or brick more extensively. Crumbling mortar needs to be replaced and damaged bricks require a professional repair or replacement.
5. Using Modern Cleaners
Older bricks are often softer and more porous, as mentioned before, so avoid cleaning with hard abrasives or extreme force. You can pressure wash on a low setting, for example, but always test to make sure the mortar can handle it. Further, only use chemical cleaners made for use on masonry.
Contact a brickwork service for more help in maintaining the historical masonry around your home.