External Masonry Chimney Maintenance Guide

Damage to the external brickwork, or masonry, of your chimney can have a major effect on its operation. On brick or clay-lined chimneys, masonry damage can extend eternally, leading to dangerous liner cracks that can result in a chimney fire. This threat isn't as severe for metal-lined chimneys, but you still don't want the external chimney to fall down around the liner. The following guide can help you prevent damage and assess current damage so you know when to schedule maintenance.

Avoid climbing plants

Climbing plants winding up a chimney can seem picturesque, but the reality is much less pleasant. The vines and tendrils of many climbing plants work into the mortar, causing it to crumble and crack. Over time the weakened mortar gives out and the chimney can fall down. If you must have plants climbing up the chimney, install proper trellising. A metal trellis that is secured to the chimney with masonry screws, but held at least 2 inches from the brick surface, allow plants to climb without damaging masonry.

Don't drill into the masonry when it's avoidable

It's never a good idea to mount something on the chimney unless you know it will be a permanent installation, such as the trellis previously mentioned. Drilling holes into the masonry for temporary use, such as hanging holiday decor, leads to unnecessary damage that weakens the masonry and also allows moisture to leach into the chimney. Generally, it's best to anchor directly into brick, as it is stronger and less prone to crumbling than mortar. Use a drill bit designed for masonry, then insert a sleeved masonry anchor into the hole.

Inspect annually for damage

Brick has a much longer lifespan than mortar, so you are mainly inspecting the mortar during your annual inspection. First, perform a visual inspection to ensure that no bricks are cracked and the mortar isn't visibly crumbling. Lightly probe the mortar with a screw driver in several spots to make sure it isn't softening and crumbling. Finally, look over the whole chimney for external issues like moss growth.

Fix damage promptly

When damage is spotted, schedule an immediate maintenance visit. A chimney repair professional can replace a broken brick or repoint the masonry -- which means removing the old mortar and replacing it with new. They can also remove moss and other stains from the brickwork. Although moss isn't damaging on its own, it can trap moisture which will eventually weaken the masonry.

For more help, contact a chimney repair service in your area.