Roof Flashing Installation in Madison, WI

Most leaks we chase in Madison turn out to be flashing, not shingles. Step flashing gets nailed through at the wrong spot, a chimney counterflashing pulls out of its mortar joint, or a plumbing boot's neoprene collar cracks and lets water ride down the pipe. We pull the shingles around the problem, replace bent or rusted pieces with new galvanized steel or .024 aluminum, and seal the reglet with polyurethane rather than tar. Then we hose-test it.

On an inspection, flashing gets more of our time than the field of the roof. We check every wall line, valley, skylight curb and chimney for lifted edges, missing kickout flashing, sealant doing a metal job, and exposed nail heads. Half the homes here were built by 1979, so plenty have had more than one roof, and the flashing underneath can be older than the shingles over it. We trace attic stains back to their source.

Tear-off is the one chance to fix flashing properly, so we never reuse the old metal. New step flashing goes in one piece per shingle course, bent from pre-finished steel. Chimneys get counterflashing cut into the mortar joints. Every valley gets ice and water shield first, and eaves get it running up past the warm wall line. With about 36 inches of snow a year, ice dams back water uphill, and that membrane is what stops it.

New construction and additions get flashing sequenced with the building, not bolted on after. Step flashing tucks behind the housewrap, drip edge goes under the underlayment at the eave and over it at the rake, and a kickout sits wherever a roof edge dies into a wall. On flat and low-slope commercial roofs, we terminate the membrane with termination bar and counterflash it. Metal roofs get matching trim, foam closures and pipe boots made for the panel profile.

We start on the roof, not in the driveway. Every wall line, chimney, skylight, vent pipe and valley gets looked at up close, because flashing fails at the joints. We look for step flashing that was face-nailed, counterflashing pulled loose from its mortar joint, and caulk doing a job that metal should be doing. In the attic, we check the sheathing under each penetration for dark stains or soft spots. Those tell us how long water has been getting in.

You get the scope on paper before anything is torn off. The estimate names each area of flashing we plan to replace and the metal we plan to use (26-gauge galvanized or prefinished steel, aluminum, or 16-ounce copper). It says whether the chimney needs new counterflashing cut into the mortar. It also states plainly what we cannot see until the shingles come up, such as rotted sheathing, and how that gets handled if we find it.

Old flashing rarely comes out clean. We lift the shingle courses along each wall or chimney by hand, break the seal strips and pull the nails, so the surrounding roof can go back down rather than be replaced. Out comes rusted step flashing, cracked rubber vent boots and the layers of tar earlier repairs smeared over the problem. The median home here was built in 1979. On a roof that age, we often find two or three generations of patches.

Once the metal is off, the wood tells the truth. Water that slipped past failed flashing usually soaks the sheathing right at the wall line or the upper corner of a chimney, where it sits longest. We probe every soft spot, cut out delaminated plywood or rotted plank back to sound material, and fit new sheathing of matching thickness so the roof plane stays flat. If a rafter has taken structural damage, we show you before going further.

Metal alone never keeps water out. The membrane beneath it does the backup work. Around every wall, chimney, skylight and valley we run self-adhered ice and water membrane, turned up the vertical surface several inches so it laps behind the siding or against the masonry. Snow piled against a wall melts slowly and sits there, and this area sees about 36 inches of it a year. Synthetic underlayment covers the open field of roof in between.

This is the step the whole job is built around. Step flashing goes in one piece per shingle course, bent to fit, nailed only on the roof side and lapped so water always runs onto the piece below. Counterflashing is let into a sawn reglet in the mortar joint and sealed there, never just glued to the brick face. Pipe boots, skylight kits and a kickout at the base of each sidewall follow. Then the shingles go back down.

Before we call it finished, we walk every flashed joint again. Each piece has to lap the right way. No nail can sit exposed in the water path, and sealant should be a finishing detail rather than the thing holding water back. Where access allows, we run a hose above the chimney or wall while someone watches from the attic. You see photos of the work, including the metal the shingles now cover.

Flashing work throws off sharp scrap: steel offcuts, bent nails, chips of mortar from the reglet cuts. We tarp the beds and siding below the work area, send debris down a chute or into a bin instead of tossing it off the eave, and haul every piece away. A magnetic sweeper goes over the driveway, lawn and walks at the end of the day. Gutters get cleared of grit so the downspouts run free.