The Metal Seam Most Homeowners Never Notice
Flashing is the sheet metal woven into the joint where a chimney passes through the roof, and it is one of the most failure-prone points on the entire structure, not because the metal itself is weak, but because that joint has to manage two different materials, brick and roofing, moving and expanding at different rates while staying watertight through every season. In Redondo Beach's beach bungalows, Spanish-style homes, and newer townhomes, flashing failure is a steady source of the water damage calls our crews respond to.
Why This Joint Is So Hard to Keep Sealed
A chimney is a rigid masonry structure sitting through a roof that flexes slightly with temperature and settles gradually over years. Flashing has to bridge that gap, staying flexible enough to accommodate small movements while remaining fully sealed against wind-driven rain. It is a genuinely difficult detail to execute well, which is part of why so much flashing work fails within a shorter span than the roofing or masonry around it.
The Three Components of a Proper Flashing System
Step Flashing
Individual pieces of metal woven into the roofing material course by course along the sides of the chimney, each piece overlapping the one below it so water is directed down and off the roof rather than finding a gap to enter.
Counter Flashing
A second layer of metal set into the mortar joints of the chimney itself and folded down over the step flashing, covering the top edge of the step flashing so water cannot get behind it from above. Counter flashing is what gives a flashing system its real weather resistance, and it is also the piece most often installed incorrectly or skipped entirely on lower-quality original work.
The Cricket
On wider chimneys, a cricket, a small peaked structure built on the uphill side of the chimney, diverts water around the chimney rather than letting it pool against the back side where the roof slope works against drainage. Chimneys without a cricket where one is needed are especially prone to water intrusion on the upslope side.
Why Redondo Beach Sees This Failure Pattern Often
Marine Layer Moisture
A musty firebox odor in summer is a frequent complaint this close to the water, and it generally traces back to humidity slipping past a worn cap or, just as often, moving in through failed flashing rather than through the masonry itself. The moisture here arrives as fog more than rain, which means flashing stays damp for long stretches even outside the rainy season, accelerating corrosion in a way that drier inland conditions do not.
Rust as the First Visible Symptom
Rust colored staining on a cap or chase cover is the marine layer at work, and it is usually the first visible clue that flashing and other exposed metal are failing too. When that staining shows up, checking the flashing seams and connections is one of the first steps, since salt moisture attacks metal starting at the joints and seams before it spreads across a flat surface.
Original Installation Quality
Not every flashing system was installed to the same standard when the home was built. Beach bungalows and older Spanish-style homes in Redondo Beach sometimes carry flashing that was adequate when new but was never built with the corrosion resistance today's coastal materials offer, meaning it simply wore out faster than a modern system would.
Signs of Flashing Failure
Water Stains on the Ceiling or Attic Near the Chimney
The clearest indoor sign. Water tracking down the inside of the chimney chase or along roof framing near the chimney almost always traces back to a flashing failure rather than a masonry crack, since flashing failure lets water in at the roofline where it can travel along framing before showing up somewhere else entirely.
Visible Rust or Corrosion on the Metal
Discoloration, pitting, or thinning metal at the flashing itself is a direct sign the material is failing, even before a leak has become obvious indoors.
Lifted or Separated Flashing Edges
Metal that has pulled away from the roofing or the mortar joint it was set into creates an open gap rather than a sealed lap joint, and that gap only grows with time and thermal cycling.
Cracked Sealant or Mortar Around Counter Flashing
Counter flashing is set into a mortar joint, and when that joint deteriorates, the flashing loses its anchor point and can work loose even if the metal itself is still in decent condition.
What Proper Flashing Repair and Replacement Involves
Removing and Replacing Rather Than Patching Over
Caulking over a failed flashing seam is a temporary measure at best. Our crews remove failed sections and reinstall step flashing, counter flashing, and crickets correctly rather than layering sealant over a system that has already failed.
Working in Code-Compliant, Corrosion-Resistant Metal
Material selection matters as much as installation technique this close to the coast. Our crews select metal to match the roof already on the house while offering real resistance to the corrosive marine air Redondo Beach properties deal with year-round.
Proper Weaving Sequence
Step flashing has to be woven into the roofing material in the correct order, piece by piece, following the same overlap pattern the shingles or tiles themselves use. Installing it out of sequence, or installing it after the roofing rather than during, is a common shortcut that leaves gaps water eventually finds.
Setting Counter Flashing Into Fresh Mortar
Counter flashing needs a sound mortar joint to anchor into. When the existing joint has deteriorated, we cut it back and reset the counter flashing into fresh mortar rather than gluing it to a failing surface that will not hold it long term.
Building or Rebuilding the Cricket
Where a cricket is missing or has deteriorated, building one correctly, with the right pitch to move water around the chimney rather than against it, addresses a chronic leak point that patchwork repairs never fully solve.
Timing Flashing Work Around Roofing
Flashing and roofing are separate trades but a shared system at the point where they meet, and the timing of a flashing repair matters. When a roof is nearing the end of its own service life, replacing flashing on its own can mean redoing that same work again once the roof itself is replaced, since reroofing typically means pulling and resetting step flashing regardless of its condition. Our crews walk through that timing with homeowners honestly, recommending a standalone flashing repair when the roof still has real life left in it, and coordinating flashing replacement with an upcoming reroof when that timeline is close enough to make sense.
Interim Protection When Work Has to Wait
If a full flashing replacement needs to wait, whether for weather, scheduling, or coordination with other roof work, temporary measures like sealing an active gap or securing a lifted edge can reduce water intrusion in the meantime. These are stopgap measures, not substitutes for proper reinstallation, and our crews are clear about that distinction so a temporary fix does not get mistaken for a finished repair.
Checking the Chimney Chase, Not Just the Flashing
Flashing failure often travels with other issues in the same area, so our crews check the chimney chase cover, the crown, and any nearby roof penetrations while we are already at the flashing, since water finding one path into a roof assembly is frequently a sign it has found, or will soon find, another.
Flashing Across the South Bay Coastline
The corrosion pattern we see driving flashing failure in Redondo Beach shows up along the whole coastal stretch of the South Bay, from the bluffs of Rancho Palos Verdes down through Torrance's coastal edge and into Long Beach's harbor-facing neighborhoods, where port air adds its own corrosive element on top of ordinary sea air.
Schedule a Flashing Inspection
If you have noticed water staining near your chimney, visible rust on roofline metal, or gaps where flashing meets the roof, contact Harris Chimney Contractors at (424) 266-4550. Our licensed crews will inspect the full flashing system, step flashing, counter flashing, and any cricket, and repair or replace what the roofline actually needs.
We serve Redondo Beach and the surrounding coastal South Bay, working in metal chosen for the conditions this stretch of coastline creates.
Need Professional Chimney Service?
Our CSIA-certified technicians are ready to help with all your chimney and fireplace needs. Contact Harris Chimney Contractors today for expert service throughout the South Bay / Palos Verdes service area.
