If Your Boston Brownstone Could Speak…

ROOF + ROOFLINE

Roof Not Draining "My roof looks flat, but I just noticed water pooling up there after rain. Shouldn’t it be draining?"

Recommendation: Flat roofs are designed with a subtle slope to direct water to internal drains or scuppers. If water is pooling, it often means drains are clogged with debris, or there may be low points in the roof surface from sagging structural members or deterioration of the roof substrate. Clear all drainage points, inspect for membrane damage, and consider adding tapered insulation or re-pitching portions of the roof to ensure effective runoff.

Ice Dams and Stains "Our top-floor ceiling has started to stain after snow melts, but it doesn’t happen during summer storms. What’s going on?"

Recommendation: Ice damming occurs when heat from the building melts rooftop snow, which then refreezes at colder roof edges. This traps water under the membrane or shingles, causing interior leaks. Improve insulation in the top floor ceiling to reduce heat loss, seal attic air leaks that allow warm air to escape, and consider installing a waterproof membrane under the roof surface near eaves and parapets to protect against future backups.

Cornice Leaks "During heavy rain, I sometimes get leaks near the top of my bay window or just under the cornice."

Recommendation: Cornices and parapets are vulnerable to water intrusion if flashing is missing, corroded, or incorrectly lapped. Examine the intersection of roof edge, parapet wall, and cornice for gaps or deteriorated joints. Replace or reseal flashing, check the integrity of coping stones, and ensure water can shed properly without backing up behind decorative elements..

EXTERIOR WALLS

Zig-Zag Cracks "There’s a strange crack zig-zagging from the corner of my window up the wall. Is that settling?"

Recommendation: These stair-step cracks typically occur in brickwork and indicate movement in the wall assembly. This could be caused by foundation settlement, thermal expansion/contraction, or failure of supporting lintels. Have a structural inspection to determine the root cause. Repair methods may include masonry repointing, steel lintel reinforcement, or localized stabilization using masonry stitching techniques.

Rust Below Lintels "Rust stains are appearing below some windows. The bricks look cracked too."

Recommendation: Hidden steel lintels can rust when water infiltrates the wall. As steel corrodes, it expands and causes surrounding bricks to crack or push outward. Remove masonry over affected openings to assess lintel condition. Replace with galvanized or stainless-steel components where needed, and rebuild with original or matching brick and soft, lime-based mortar.

Bulging Brick Wall "There’s a bulge in the back wall—like it’s starting to bow outward."

Recommendation: Bulging usually results from separation between the inner and outer wythes of a multi-wythe brick wall, often caused by mortar failure, water damage, or structural overload. Assess the wall for tie rod failure or moisture intrusion. Stabilize by rebuilding damaged sections, reinstalling wall ties or using helical anchors, and repointing with compatible mortar.

Crumbly Brownstone "The brownstone surface is flaking around the windows."

Recommendation: This is a sign of delamination, common in brownstone due to its layered composition. Water penetrates and causes the surface to peel in thin sheets, especially under freeze-thaw cycles. Damaged areas should be carefully removed and patched with color-matched restoration mortar. Severely deteriorated elements may require full stone replacement using salvaged or newly quarried stone with matching mineral characteristics.

Ivy Damage "The ivy on the side wall looks charming, but I heard it might cause problems."

Recommendation: Ivy clings to masonry using root-like tendrils that penetrate mortar joints, accelerating decay and trapping moisture against the wall. Remove ivy by cutting it at the base and allowing it to die back naturally. After removal, inspect for biological staining and loose mortar. Repoint compromised joints and avoid replanting climbing vines directly on masonry.

Neighbor Separation "Hairline cracks are forming between our unit and the building next door."

Recommendation: These vertical cracks may indicate differential settlement between adjoining structures. Use telltale monitors to track movement over time. If active movement is detected, consider soil testing and targeted underpinning to stabilize foundations on the shifting side. Repoint cracked masonry joints using flexible lime mortar that accommodates subtle movement.