Chimney Masonry Repair in Hastings Ranch, Joint by Joint

Mortar is supposed to wear out before the brick does. It is the sacrificial part of the wall, and over decades of sun, rain and small earthquakes it turns sandy and starts to fall out of the joints. Once a joint is open, three things happen. Rain soaks into the brick and freezes or simply stays wet, which breaks the brick face off over time. Roots from vines and wind-blown seeds take hold in the gap. And small animals find a way in: roof rats squeeze through surprisingly narrow holes near the roofline, and paper wasps and bees build in recessed joints and behind loose bricks. On older Hastings Ranch homes, we often find all three on the same chimney.

We start by finding every open joint and loose brick, mapping them in photos, and checking whether the problem is limited to the top few courses, where weather hits hardest, or runs further down. If wasps or bees are active, they are dealt with first, by a pest professional when needed. Then we grind out the failed mortar to a consistent depth and repoint. Gaps that animals have been using are packed solid. The finished joints are tooled to match the old ones so the repair does not stand out from the street.

Brick laid before the 1930s was often set in lime-rich mortar that is softer than modern cement mixes. If you repoint that brick with a hard, modern mortar, the new joints end up stronger than the brick around them, and when the wall moves or gets wet, the brick cracks instead of the joint. That is the opposite of what you want. So we look at the age and hardness of the brick and the original mortar, and we choose a mix that is a little softer than the brick. On older chimneys that usually means a lime-based or low-strength mortar; on postwar brick, a standard mix is fine.

Spalled bricks, where the face has popped off, are cut out and replaced with brick matched for size and color as closely as we can find. Once the joints have cured, we can apply a breathable water repellent that lets moisture out of the brick while slowing rain getting in. We will not put a sealer on brick that is already wet inside, since it traps the water. Every masonry job is quoted in writing after we have seen the chimney, and if the damage is too extensive for repointing to make sense, we will tell you that too.