Chimney Flashing Repair in Marietta, GA
If your ceiling is staining near the chimney, the chimney itself is almost never the cause. The cause is the flashing where the chimney meets the roof. Chimney flashing is the most leak-prone detail on most homes because it has to do five things at once: shed water down-slope, divert water from the high side around the chimney, seal against masonry that doesn't hold a seal well, accommodate movement between two materials that expand at different rates, and survive 30 years of weather.
Done right, chimney flashing lasts the life of the roof. Done poorly (most of what we see), it leaks within 5 to 10 years. We fix it permanently across Marietta, GA and Cobb County.
The Four Pieces of a Proper Chimney Flashing System
Apron flashing (downhill side)
A single piece of L-flashing across the bottom of the chimney, woven into the shingles below.
Step flashing (sides)
Individual L-pieces, one per shingle course, layered up the sides of the chimney. Each piece overlaps the one below by at least 2 inches and is woven into the shingle course.
Cricket or saddle (uphill side, on chimneys 30 inches wide or wider)
A small ridged structure that diverts water around either side of the chimney rather than letting it pile up against the back. Required by code on wider chimneys, often missing on Cobb County homes built before 2000.
Counter flashing (over the top of step and apron)
Metal that's bent into a slot cut into the masonry mortar joint, covering the top edge of the step and apron flashing. Sealed with proper masonry sealant. This is the piece that fails most often. The slot wasn't cut deep enough, the mortar pulls back, the counter flashing pulls out, water gets behind.
Why Chimney Flashing Fails
Caulk instead of metal
Many chimneys have a glob of caulk where there should be counter flashing. Caulk fails in 3 to 5 years guaranteed. We pull it, cut a proper slot in the mortar, and install metal counter flashing.
Single-piece L-flashing instead of step flashing
A continuous bent piece running the full height of the chimney instead of individual stepped pieces. Doesn't move with the shingles, leaks at every shingle course intersection. We strip it and install proper step flashing.
Missing cricket on wide chimney
Water piles up against the back of the chimney during a rain. Eventually finds its way past whatever flashing is there. We build a proper cricket using framing lumber and roofing material.
Mortar joint failure
The masonry itself can pull back, releasing the counter flashing. We re-tuck the mortar joint and re-set the counter flashing.
How We Re-Flash a Chimney Properly
Strip shingles back two feet on all four sides. Remove old flashing entirely. Inspect decking for rot, replace anything soft. Install new ice-and-water membrane base layer. Install new step flashing on the sides woven into new shingle courses. Install new apron flashing on the downhill side. Build cricket if needed (or re-build if existing one is undersized). Install fresh counter flashing into newly tucked mortar joints, sealed with masonry sealant. Re-shingle around the chimney.
What Chimney Flashing Repair Costs in Cobb County
Standard chimney re-flash runs $800 to $2,200 depending on chimney size, complexity, and whether a cricket needs to be built. Cricket addition adds $400 to $900. Mortar re-tuck (if masonry has deteriorated) adds $200 to $600. Decking replacement under the chimney adds material cost.
Get a Free Chimney Flashing Inspection
Call (678) 720-3565 or use the contact form. Free inspection with photos showing exactly what's leaking and what it'll take to fix.