Step flashing replacement is the repair we do most. Step flashing is a run of small L-shaped metal pieces, one tucked under each shingle course, climbing the side of the chimney like stairs. When one piece rusts through or a roofer skipped it during a reroof, water runs straight down the brick and into the attic.
Our crew pulls the shingles back along the chimney, removes the old pieces and weaves in new ones, each overlapping the one below by at least two inches. We use pre-bent aluminum or galvanized steel on most homes and copper on slate or historic roofs. Each piece is nailed to the roof deck only, never to the masonry, so the house and the chimney can move on their own without tearing the metal.
The most common failure we find is a single long strip of metal laid flat against the side of the chimney and sealed with caulk. It looks fine from the ground. It leaks inside two winters.
Step flashing only works with a cap over it, so we usually pair this job with counter flashing repair. If the top edge of the brick is also soaking up water, chimney waterproofing is the next step. Call (833) 583-1301 and we will tell you what we see before we touch a shingle.