Chimney masonry contractor for repairs in Lake Cain Hills

The mortar types named in ASTM C270

ASTM C270 sorts mortar for unit masonry into types, and Technical Note 8B summarizes them. Your estimate names the type we propose for your chimney and explains why it suits the brick and the existing joints.

• Type M, high compressive strength but not very workable
• Type S, all-purpose with higher compressive and flexural bond strength
• Type N, all-purpose with good bonding and workability
• Type O, low strength, used mostly inside and for restoration

Masonry and flashing at the roofline

Counterflashing at the roofline is often set into the chimney's mortar joints. When those joints fail, the flashing can pull loose, and when the flashing fails, water soaks the masonry around it.

We look at both together. Masonry repair near the flashing is done with the flashing in mind, and any flashing repair or replacement is quoted separately, so you can see what each part of the fix involves. Where new counterflashing has to be cut into the masonry, the reglet is placed in a sound joint, and that joint is repaired first if it needs it.

Brick veneer chimneys and their air space

Some chimneys are a brick veneer over a framed chase, with an air space and weeps behind the brick to let water drain out. Technical Note 46 cautions that when veneer brick is removed, debris must not fall into that air space, where it can block the weeps.

We protect the cavity during the repair, keep the weeps open and check that water can still drain at the base once the work is finished. Clogged weeps found during the repair are cleared carefully, since the flashing behind them can be damaged by a probe pushed too far.

Putting repairs in the right order

When a chimney has several problems, the order matters. Masonry that could fall comes first, then the paths that let water into the house, then appearance.

We set out the repairs in that order in the estimate and tell you which ones can reasonably wait. That lets you plan the work and the budget without leaving anything unsafe in the meantime. If the budget allows only part of the work now, the estimate shows which items belong in the first visit and what the rest will involve later.