Chimney Flashing Repair

Flashing is the watertight transition where the chimney meets the roof, and it is the leak point homeowners least suspect and contractors most often botch. Done right, it is a two-part system: step flashing — individual L-shaped pieces woven course-by-course into the shingles up the sidewall — and counter-flashing set into a saw-cut reglet in the masonry and folded down over the step pieces. Done wrong, it is a bead of caulk smeared over a gap, which is exactly the "repair" that fails within a season and sends water into the structure. Prime Chimney Experts flashes chimneys as the layered, mechanical, watertight assembly it is meant to be, because no amount of waterproofing the brick helps if the roofline transition is open.

We diagnose first and repair to the right depth. A sound flashing system with a failed seal may need only the reglet reservoir re-tooled and re-sealed; a corroded or improperly installed one needs to come out entirely and be rebuilt — new step flashing woven into the shingles, new counter-flashing cut into a fresh reglet, lead or aluminum to suit the roof. We dress fatigued lead back down, solder copper and galvanized corners for a watertight non-caulk joint where the detail demands it, and drill weep holes where water is trapped in the masonry cavity. On a wide chimney, or one sitting in a roof dead-valley that ponds water, the real fix isn't more flashing — it's a cricket: a peaked metal or framed saddle built on the uphill side that diverts water and debris around the stack instead of letting it dam against the back wall. Where the wood cant or substrate beneath the cricket has rotted, we replace it before re-metaling, because new flashing over rotted backing is a guaranteed callback.

The harder roof geometries are where flashing failures hide, and where most contractors are out of their depth. A chimney that sits in a dead-valley — a low spot where two roof planes funnel water toward it — will pond and leak no matter how clean the step flashing is, and the real remedy is a diverter that moves the water away before it reaches the stack. Trapped water inside a masonry cavity needs weep holes drilled at the flashing line to drain it, or it simply sits and finds another path in. A counter-flashing reglet needs the sealant tooled into a proper backed reservoir, not smeared across the surface, or it pulls away as the building moves. On a flat commercial roof, an irregular stack penetration may need a poured pitch pan rather than conventional flashing entirely. We diagnose the geometry, not just the metal, because the leak is often a water-management problem the original flashing was never designed to solve.

This is detail work where craftsmanship is literally watertight or it isn't — there is no partial credit on a flashing joint. We document the condition, explain whether a reseal or a full replacement is honestly warranted, and build the transition to shed water for the long term rather than buy a season with sealant. The same flashing-and-cricket standard governs the work across our national network, with crickets specified wherever chimney width or roof geometry demands one rather than treated as an upsell. Get the roofline transition right and you have closed the leak point that defeats every other waterproofing measure — which is why we treat flashing as the precision work it is, not the caulk-gun afterthought it's too often reduced to.