Chimney Flashing Repair in Sherman Oaks, Built to the Code Detail

Where a chimney passes through the roof, the code calls for flashing and counterflashing, two layers of metal that work as a pair. Step flashing is woven into the roofing along each side, one piece per course of shingles, so water running down the roof sheds over it. Counterflashing is set into a saw-cut groove in the chimney's mortar and folds down over the step flashing, so water running down the brick lands on top of it and never behind. When the counterflashing is only caulked to the face of the brick instead of let into a joint, the caulk dries and pulls away within a few Valley summers, and water runs behind the flashing into the attic. That shortcut is the flashing failure we find most often in Sherman Oaks, usually left behind by a reroof where the chimney was flashed in a hurry.

The cricket is the other half of the detail. A cricket, or saddle, is a small peaked roof built on the uphill side of the chimney to split water around it rather than letting it pool. The code requires one when the chimney is wider than 30 inches across that uphill face, which covers many of the wide brick chimneys on Valley ranch houses with a fireplace flue and a furnace flue side by side. Without one, leaves and water collect behind the chimney and work through even good flashing. Tile roofs, common on Spanish-style homes in Encino and the Sherman Oaks hills, need flashing shaped to the tile profile, and the tile has to be lifted and reset with care. We note the roof type when you book, so the right metal and the right crew arrive together.

A ceiling stain beside the chimney does not always mean flashing. The same stain can come from a cracked crown, an uncapped flue taking rain straight down, porous brick soaking water through, or a roof leak a few feet away that runs along a rafter. Replacing flashing that was never the problem wastes money and leaves the leak in place. So we trace first. We start at the top with the cap and crown, look at the brick and mortar for water paths, then check the flashing, the cricket and the roofing around them, and finish in the attic where the water appears. Sometimes a hose test, wetting one area at a time, is the only way to prove the source, and we will tell you when it is needed. The quote names the cause and shows the photo.

Flashing repairs are quoted in writing after the leak is traced, because the scope runs from resealing one counterflashing joint to replacing the full set and framing a cricket. If you are reroofing, call us before the new roof goes on: flashing installed with the roof is cheaper and cleaner than cutting into new shingles later. We work with your roofer or on our own, flash the chimney side of the detail with metal suited to the roof, and reseal the counterflashing grooves with mortar or a sealant rated for masonry. If staining shows up after the first heavy storm of the season in Sherman Oaks, send one photo of the ceiling and one of the roof around the chimney. From those two pictures we can usually tell you where the trace should begin.