Roof Leak Repair in Sterling Heights, MI

Every drain in the house vents through the roof, and each vent pipe passes through a boot: a flat flashing base tucked under the shingle course above and lapped over the course below, with a rubber, plastic or metal collar around the pipe. The rubber collar is what gives out. Sun and cold harden it until it splits, and water rides down the outside of the pipe into the ceiling under it, often a bathroom or hallway. The residential code leaves vent-pipe flashing to the shingle maker's printed instructions. A lasting repair swaps the boot and reseats the shingles around it, where caulk around a split collar would only buy time. HomeGuide puts a cracked boot replacement at $250 to $600, more on a steep or high roof. If one boot has failed, have the others priced too. They're the same age.

A valley takes the runoff from two roof planes at once, and the code allows it open or closed. An open valley has a metal lining at least 24 inches wide (or two plies of mineral-surfaced roll roofing) with the shingles trimmed back to expose it. A closed valley has shingles running across a lining of 36-inch smooth roll roofing or a self-adhering ice-barrier membrane (ASTM D1970). Leaks start where nails were driven too close to the valley center, where the cut shingle edge was never sealed, or where an old metal lining has rusted through. Maple and oak leaves make it worse: a wet leaf mat holds water in the valley for days after the rain stops. HomeGuide prices a valley leak at $300 to $1,500, and the usual repair pulls and relays the valley flashing.

Where a roof slope runs into a wall (a dormer cheek, or the upper-storey wall above an attached garage), step flashing seals the joint. Each shingle course gets its own bent piece, at least 4 inches up the wall and 4 inches onto the roof, with the vertical leg tucked behind the siding. At the bottom of the wall, a kickout flashing turns the water into the gutter instead of letting it run down inside the wall. When step flashing was face-nailed, skipped or reused from an older roof, the leak shows as a stain under the dormer window or soft wood in the garage header. Fixing it means lifting siding and shingles along the wall rather than running sealant down the seam. Brick walls also need counterflashing over the steps, the same detail covered on the chimney flashing repair page.

A leak that appears along the top of an outside wall in January, with no rain in the forecast, is usually ice. Water melting higher up refreezes at the cold overhang, pools behind it and creeps up under shingles that were made to shed water, not hold it. Inside, you'll see a stain along the ceiling edge or water at the top of a window frame. There are two jobs here. First, repair what got wet: HomeGuide lists $1,500 to $5,000 or more for leak repair and restoration after ice damming, separate from $350 to $1,500 to remove the ice. Second, stop it next winter with an ice barrier at the eaves and a colder attic, both explained on the ice dam removal page.

Some winter drips have nothing to do with the shingles. Warm, humid air from the living space leaks into the attic around light fixtures, plumbing chases and wiring holes, then condenses on the coldest surfaces up there: the nail tips poking through the deck and the underside of the sheathing. On a cold night it freezes into frost. On the first mild day it melts, and you get scattered drips across the ceiling instead of one stain, sometimes after a dry week. New shingles won't fix that. The cure is air sealing at the ceiling, bath fans ducted outdoors and balanced roof ventilation. If the leak only happens in winter, ask the roofer to look in the attic on a cold morning before quoting any roof work.