Brick chimney rising through a gray shingle roof with metal flashing at its base

Roof Flashing Repair: Where Flashing Goes and Why It Fails

Most roof leaks start at the metal, not the shingles. See where every piece of flashing belongs, then call one free number to reach an independent DFW roofing company that repairs it.

Call (469) 649-7066 See the flashing map

The short answer: wherever the roof is interrupted

Flashing goes anywhere water could slip past the shingles: where a roof meets a wall or chimney, where two slopes meet in a valley, along the edges, and around every pipe, vent and skylight that punches through. It is thin metal (sometimes rubber or a membrane) shaped to send water back onto the shingle surface.

Sidewalls: step flashing under each shingle course, with counterflashing or siding over it.
Chimneys: an apron at the front, steps along the sides, a back pan or cricket behind, and counterflashing set into the masonry.
Valleys: a metal or membrane lining in the trough.
Eaves and rakes: drip edge.
Roof eave against a wall: a kickout diverter.
Penetrations: pipe boots, vent flashing and skylight kits.

DFW Expert Roofers is a free phone line and does no roof work. Call it and an automated assistant connects you to an independent roofing company that is locally owned and repairs flashing in your part of the metroplex.

Roofer sealing around a roof vent pipe with a caulk gun on an asphalt shingle roof at sunrise

Flashing map: each piece and its job

Read this from the top of the house down, the way water travels. The right-hand column gives the model code section or industry manual a roofer would follow.

Where	Flashing	What it does	Reference
Behind a chimney (uphill side)	Back pan, or a cricket (saddle)	Splits water around the chimney so it cannot pool behind it	IRC R903.2.2: cricket required on chimneys over 30 inches wide
Sides of a chimney or dormer	Step flashing plus counterflashing	Steps shed water course by course; counterflashing covers their tops	ARMA Residential Manual, chapter 10
Front of a chimney	Apron flashing	Carries water over the lower edge onto the shingles below	ARMA: apron fastened to deck, counterflashing to masonry
Roof slope meeting a sidewall	Step flashing	One piece per course, tucked under each shingle	IRC R905.2.8.3: at least 4 by 4 inches
Roof below a second-story wall (front wall)	Continuous apron flashing	Turns water from the wall onto the roof below	IRC: per the shingle maker's instructions
Valleys	Open metal lining, or underlayment under a closed or woven valley	Channels water from two slopes	IRC R905.2.8.2: open metal at least 24 inches wide
Pipes and vents	Pipe boots and vent flashing	Seals around round and square penetrations	IRC: per the shingle maker's instructions
Bottom of a roof-to-wall joint	Kickout diverter	Throws water away from the wall into the gutter	Model residential code, chapter 9
Eaves and rakes	Drip edge	Carries water past the fascia and protects the deck edge	IRC R905.2.8.5

Where flashing is metal, the code calls for corrosion-resistant material no thinner than 0.019 inch, equal to 26-gauge galvanized steel (IRC R903.2.1). Your city enforces its own adopted edition, so section numbers can shift slightly.

How each kind of flashing is supposed to work

Step flashing and counterflashing

The Asphalt Roofing Manufacturers Association describes step flashing as roughly 10-inch pieces, at least 2 inches wider than the shingle exposure, set one per course and nailed to the deck, never the wall. Siding should come down at least 2 inches over the vertical leg, acting as the counterflashing. On brick, a separate metal counterflashing is set into the mortar joint.

Chimney flashing and crickets

A chimney moves a little apart from the roof framing. ARMA's answer is two parts: base flashing fastened to the roof, counterflashing fastened to the masonry, so one slides over the other without opening a gap. It strongly recommends a cricket on any chimney 24 inches or wider; the IRC requires one above 30 inches.

Metal valleys

An open valley leaves a band of metal exposed down the center. ARMA lists 26-gauge G-90 galvanized steel, 16-ounce copper or 0.025-inch aluminum as minimums, and warns against shingle end joints in a valley. Closed-cut and woven valleys hide the trough under shingles instead. Each style works when installed to the shingle maker's instructions.

Drip edge

The metal lip along the eaves and the sloped rake edges. It keeps water from curling back onto the fascia and deck edge. The code wants it lapped at joints, fastened at close spacing, and set so underlayment runs over it at the eaves but under it at the rakes.

Kickout flashing

Where the lower edge of a roof dies into a wall (a garage roof against a two-story wall, for instance), the last step flashing must turn water out into the gutter. A missing kickout is one of the classic causes of rotted wall sheathing and stained interior walls below.

Pipe and vent flashing

Plumbing vents usually get a boot: a metal or plastic base with a rubber collar that hugs the pipe. Box vents and exhaust caps have their own flanges. The base slides under the shingles above it and laps over the shingles below, so water runs over it, never under it.

Why flashing wears out on North Texas roofs

Close view of a gutter and downspout corner on a brick home below a shingle roof edge

Heat cycling. The National Weather Service office in Fort Worth puts the DFW normal at about 20 days a year at 100 degrees or above (1991 to 2020), and 2011 logged 71. Metal on a roof heats and cools every day, and that movement works on nails, sealant and the joint between metal and brick. A flashing detail that relies on a bead of caulk instead of overlapping metal tends to open up first.

Rubber in the sun. Pipe boot collars and some sealants harden and crack with years of ultraviolet exposure. A split collar lets water run straight down the pipe.

Hail on soft metal. Aluminum and copper are softer than steel, and hail can dent valley metal, drip edge, vent caps and chimney counterflashing. A dent alone may be cosmetic; a crease that breaks a seam or lifts a lap is a leak path. After a storm, dented gutters, downspouts and vent caps seen from the yard are a sign to have the roof flashing checked. See hail damage roof repair.

Brick and siding work. New siding, stucco or a repointed chimney can bury or cut counterflashing. Ask whoever did that work whether the flashing was reset.

Signs of failed flashing, and what to ask the roofer

Clues you can spot safely

A ceiling or wall stain next to a chimney, dormer or second-story wall
Drips that appear only in wind-blown rain from one side
Rust streaks or gaps where metal meets brick, seen from the yard
Water staining on siding below a roof-to-wall corner
Dented vent caps or valley metal after hail

Questions for the roofer

Will you replace the flashing or just reseal it, and how long will each last?
Is the counterflashing cut into the mortar or only glued to the brick face?
Does this wall need a kickout, and is there one?
Will the shingles along the wall survive being lifted, or will some need replacing?
What metal and gauge are you using?

Many roofers check a leak at no charge, though not all do; ask during the call.

Getting flashing repaired through the line

Close view of asphalt shingles with dark round hail marks where granules were knocked off

Leave the roof to the roofer. A wet or storm-hit roof is slippery, and damaged decking can give way, so keep off it and keep the ladder put away. Stay clear of any downed power line and report it to Oncor or your local electric utility, or call 911. Inside, pull furniture and electronics away from the drip, set out a bucket or towels, and keep everyone out of a room where the ceiling is sagging. Take photos from the yard and from inside, then call your insurance company and a roofer.

Dial the lineAn automated assistant picks up (469) 649-7066 any time and asks what you need. The same number also takes air conditioning, heating and pressure washing calls, so say "roof".
Tell it about the roofHail, a drip in the ceiling, shingles in the yard, a tree limb, or an aging roof you want checked, plus your town and how soon you need someone.
Get transferredThe call goes to an independent roofing company that is locally owned and works in Dallas-Fort Worth. It hears a quick summary of your call before it answers.
Work with that companyIt inspects, prices and does the job, and you pay it (or your insurer does, as you arrange). If it cannot pick up, it gets your name, number, town and need so it can call you back.

No state license for roofers. Texas does not license roofing contractors. A 2025 bill that would have had the state license re-roofers (HB 3344) cleared a House committee but never got a floor vote, and it died when the session ended. That puts the checking on you: ask for a certificate of liability insurance sent to you by the roofer's insurance agent or insurer, a written contract that lists the full scope, the permit or contractor registration your city requires, addresses of nearby jobs, and proof the shingle warranty was registered. The line does none of this checking for you. How to check a roofer in Texas.

About this line: DFW Expert Roofers is a free phone line, not a roofing contractor. It answers your call and connects you with an independent local roofing company, which inspects, quotes and does the work, and which you pay directly. Companies may pay a referral fee. Calling the line costs you nothing. See how a call is handled.

More pages that may help

Flashing repair across the metroplex

Flashing questions homeowners ask

Where does flashing go on a roof?

Anywhere the shingle surface stops, changes direction or is cut open. That means along sidewalls and second-story walls (step flashing, covered by counterflashing), around chimneys (apron, step, back pan or cricket, and counterflashing), in valleys, along eave and rake edges (drip edge), where a lower roof edge dies into a wall (kickout), and around every pipe, vent and skylight. The flashing map on this page shows each one.

What is a metal valley on a roof?

A valley is the trough where two roof slopes meet. In an open metal valley, a strip of sheet metal lines the trough and the shingles are trimmed back to leave it exposed, so water runs down the metal. The 2021 International Residential Code calls for open metal valley linings at least 24 inches wide. Closed and woven valleys cover the trough with shingles instead, over an underlayment lining.

Does step flashing go over or under the shingles?

Under. Each L-shaped piece is tucked beneath a shingle course as that course is laid, with one leg on the deck and the other standing up the wall, and the next shingle covers it. The Asphalt Roofing Manufacturers Association says to nail it to the roof deck, never to the wall. Siding or a counterflashing then laps down over the upright leg.

Can flashing be fixed without replacing the whole roof?

Often, yes. A roofer can lift the shingles along a wall or around a chimney, replace the step or apron pieces, install new counterflashing, and relay the shingles, as long as they are still flexible. Pipe boots and kickouts are usually simple swaps. On an old, brittle roof the shingles may crack when lifted, which changes the math; see roof repair.

Is kickout flashing really required?

The model residential code requires flashing that turns water away where the lower edge of a sloped roof runs into a sidewall, which is the job a kickout does. Without it, water from the roof edge can pour down behind the siding or brick and rot the wall. Ask the roofer to check for kickouts at every spot where a roof eave meets a wall, especially near garages and porches.

Leak at a wall, chimney or vent? Call the free line

Say what the roof is doing and which town you are in. The automated assistant passes you to an independent roofing company that is locally owned and works in DFW. That company comes out, looks at the roof and prices the job itself.

Call (469) 649-7066

Picks up day or nightStorms here often hit in the evening. The assistant answers at 2 a.m. the same as at noon.
Costs you nothingThe line sends no bill. Any price you hear comes from the roofer, and you can ask for it on paper.
Check before you hireTexas issues no roofing license, so ask for an insurance certificate, a written contract and the permit your city requires.
Your call to makeListen to what the roofer found, read the estimate, and say yes only when it adds up.