Our Services
Our approach to chimney masonry in Longwood
Brick industry guidance and the building code, applied to chimney repairs in Longwood.
Mortar chosen for a chimney's exposure
ASTM C270 sorts masonry mortar into types by strength and makeup. For chimneys above grade, the Brick Industry Association's mortar guide recommends Type N, with Type S as the alternate, and it advises choosing the lowest strength that still meets the job's needs.
A chimney stands out in the weather on every side, so the mix has to handle repeated wetting and drying while staying compatible with the brick around it. We name the mortar type on your estimate so you know what is going into the joints and why it suits your chimney. If the existing mortar is unusual, we say so and explain how that changes the choice.
Why stronger mortar can harm old brick
Using the hardest mortar available sounds sensible, but guidance from the National Park Service and the Brick Industry Association points the other way. Repair mortar should be softer and more vapor permeable than the bricks it joins, and no harder than the mortar already in the wall.
Hard, dense mortar leaves moisture and stress nowhere to go except into the brick faces, which can crack or pop off at the edges. Keeping the joint as the weaker part of the wall means future wear shows up in mortar, which is far easier and cheaper to renew than brick. Our masons match the mix to the chimney for that reason.
Sealers after the masonry is repaired
A water repellent can help brick shed rain, but the type matters. Brick Industry Association maintenance guidance says only repellents that let water vapor escape, such as silanes and siloxanes, should be used on exterior brickwork, and that film-forming coatings should not be applied at all.
The same guidance warns that coatings are no substitute for flashing and other details that turn water away. We finish the repair and fix the water path first, then tell you whether a breathable repellent is worth adding on your chimney. Waterproofing is priced on its own line, so it stays your choice and never hides inside the masonry price.
