Chimney Repointing & Masonry Pittsburgh PA

Check for these signs of mortar deterioration:

• Mortar joints that are crumbling, cracking, or receding deeper than the brick face
• White chalky deposits (efflorescence) on the brick surface
• Loose bricks or bricks that can be wiggled by hand
• Water stains on interior walls or ceiling near the chimney
• Mortar pieces or sand-like debris collecting on the roof or ground below the chimney

Properly executed chimney repointing with the correct mortar type lasts 25-30 years in Pittsburgh's climate. The key is using the right mortar hardness — Type O or K for pre-1950 soft brick, Type N or S for modern hard brick — and grinding to proper depth (minimum 3/4 inch). Shallow repointing or mismatched mortar can fail in as little as 3-5 years.

Chimney flashing is the metal barrier between your chimney and roof surface. It's the #1 source of chimney-related leaks because it requires precise coordination between the roofing system and the masonry. Step flashing weaves into the shingles, counter flashing is embedded into the mortar joints, and kickout diverters redirect water at the bottom corners. When these three components are installed as one system by one contractor, the result is watertight. When installed separately, gaps are almost inevitable.

Yes — and this is our strongest recommendation. When your chimney repointing, crown repair, and flashing installation happen simultaneously with your [roof replacement](/services/roof-replacement), every detail is coordinated perfectly. The step flashing, counter flashing, and shingle integration are all done by the same crew at the same time. This eliminates the coordination failures that happen when a roofer and mason work separately.

We use Type N or S mortar for modern brick chimneys. However, pre-1950 chimneys built with softer historic clay bricks require Type O or K mortar. Applying hard modern mortar to soft historic bricks will prevent natural moisture breathing, causing bricks to crack and pop during freeze-thaw cycles.

The chimney crown is the concrete slab that covers the top brick course of the chimney, slanted outward to shed water. When it cracks or crumbles, water enters the brick interior, causing rapid masonry decay. We patch minor cracks or pour new reinforced concrete crowns.

A chimney cap is a metal hood mounted over the flue opening. It prevents direct rain and snow from entering the flue pipe, stops wind downdrafts from blowing soot into your home, and features mesh screens to block nesting birds and raccoons.

Chimneys stand above the roof line, exposed to 360 degrees of wind, rain, and freeze-thaw cycles. They also handle hot flue gases that combine with moisture to form weak acids, which eat away at mortar joints from the inside out.

A chimney cricket is a peak-shaped wooden diverter built on the high side of a chimney. It is required by building codes for chimneys wider than 30 inches to redirect water runoff around the chimney corners, preventing ice dams and leaf accumulation.

No, it is not safe. Crumbling mortar indicates structural decay and can allow carbon monoxide and heat to escape through joints into your attic or walls, posing a serious fire hazard and health risk. Repointing should be done first.