Metal roof flashing is the shaped sheet metal that seals every place a roof changes direction, meets a wall or has a hole cut through it. On Dallas-Fort Worth homes those spots, chimneys, headwalls at brick, dead valleys, pipe boots and skylights, are where nearly every leak we trace begins. The roofing itself rarely fails; the joint does.
This guide shows where DFW roofs leak, which flashing goes where, why fabricated metal beats a tube of caulk, what to check after hail and why flashing should be replaced with the roof. We bend all of it in our own custom sheet metal shop; the metal flashing service page lists what we make.
Where do DFW roofs actually leak?
At the transitions, almost every time. The open field of a roof, metal or shingle, sheds water on its own. Leaks start where water has to turn, slow down or get past an obstacle, and in DFW that means the five spots below.
Chimneys
A brick chimney needs step flashing woven up each side, an apron across the front, a cricket behind it and counter-flashing let into the mortar joints over all of it. On many 1970s-to-1990s DFW homes the counter-flashing was surface-mounted and caulked instead, and the cricket was never built. The residential code calls for a cricket on chimneys wider than 30 inches, because without one leaves and water pile up on the uphill side.
Headwalls and sidewalls at brick
Where a lower roof runs into a wall, a porch roof into the house for example, an apron flashing goes under the roofing and up the wall, and counter-flashing comes down over it. Where a roof runs alongside a wall, step flashing laps into each course. At the bottom of that run, a kick-out flashing throws water into the gutter instead of behind the brick veneer. A missing kick-out is the most common cause of the rotten corner we find behind DFW brick.
Dead valleys
A dead valley is where two slopes meet and the water has nowhere to go but a wall or a flat pocket. Complex roofs with several gables, common across Collin and Denton County subdivisions, have them. A dead valley needs a one-piece fabricated pan with turned-up edges and a high-temperature self-adhered membrane under it, not overlapping shingles and tar.
Pipe boots and skylights
Plumbing vents are sealed with a boot, and the rubber ones crack after years in Texas sun, usually well before the roof wears out. We use boots with a formed metal base and a storm collar; on our estimates they run $200 each. Skylights need head, sill and step flashing made for the curb, and custom skylight flashing is $1,000 each. Satellite dish lags and HVAC curbs round out the list.
What are the main types of roof flashing?
Each type handles one kind of joint. Most roofs use six or more of them, and on a metal roof every one is fabricated to the panel profile.
| Type | Where it goes | What it does |
|---|---|---|
| Step flashing | Sidewalls, chimney sides | Short L-shaped pieces lapped into each course so water steps down and out |
| Counter-flashing | Over step and apron flashing at masonry | Set into a cut mortar joint; covers the top edge so water cannot get behind |
| Apron (headwall) flashing | Where a slope dies into a wall | Runs under the roofing and up the wall beneath the counter-flashing |
| Valley flashing | Open valleys | W-profile pan with a center rib that keeps the two streams from crossing |
| Kick-out flashing | Bottom of a sidewall run | Diverts water into the gutter instead of behind siding or brick |
| Cricket or saddle | Uphill side of a chimney or curb | Splits water around the obstacle |
| Drip edge | Eaves and rakes | Pulls water off the deck edge into the gutter |
| Pipe boot and storm collar | Vent pipes | Seals the pipe and sheds water over the seal |
| Z-closure and transition flashing | Ridges and pitch changes on metal roofs | Closes the panel ribs and laps the upper panel over the lower |
Material follows the roof. We use 24- or 26-gauge Galvalume steel prepainted to match a Kynar 500 roof, .032 aluminum where weight or forming calls for it, and 16-ounce copper on copper roofs. The metals have to be compatible: copper runoff over Galvalume and aluminum against treated lumber both corrode, so we isolate them.
Why does fabricated flashing beat caulk?
Because caulk is a sealant, not a water barrier. Flashing works by gravity and overlap: every piece laps over the one below it, so water runs out even with no sealant at all. Sealant is the backup, never the plan. Roof cement smeared over a joint is the opposite; it blocks the drainage path, then cracks.
DFW makes that worse. The region averages about 20 days a year at or above 100°F, roof surfaces run far hotter, and the summer UV index routinely reaches 9 to 10. Exterior sealants typically need renewal every few years in those conditions. Hemmed edges, soldered or riveted corners, mortar-cut counter-flashing and one-piece crickets do not.
- Laps run with the water, at least 4 inches, with hemmed edges that stiffen the metal and hide the cut.
- Counter-flashing sits in a reglet cut into the mortar joint, not glued to the brick face.
- Crickets and dead valley pans are made as one piece in the shop, with corners soldered or sealed from inside.
- A high-temperature self-adhered membrane, rated to 240°F or higher, goes under every flashing on a metal roof.
- Gauge matches the roof, so hail does not crease the flashing before it marks the panel.
What should you check on flashing after a hail storm?
Hail dents in flashing are usually cosmetic, but the storms that bring hail to DFW also bring wind, and the post-storm inspection is when lifted counter-flashing, cracked boots and split sealant get found. Texas has led the nation in major hail events for 11 straight years, and Dallas sees roughly 10 to 20 hail events a year, so this is a yearly job.
- Pipe boots: cracked or chalky rubber, a storm collar lifted off the pipe.
- Counter-flashing: pulled out of the mortar, bent up, or caulk that has split away from the brick.
- Crickets and valleys: dents that form a low spot where water will pond and debris will stop.
- Closures: creased ribs at Z-closures on metal roofs; granule loss at flashing edges on shingle roofs.
- Inside: stains on ceilings along outside walls and around the chimney after the next rain.
Be careful who inspects. After every big DFW storm, out-of-town crews knock doors, claim leftover materials and push for a signature on the spot; the Texas Attorney General warns against all three. Get a written inspection from a company with a local address, and read our metal roof repair page on what an honest hail inspection covers. Remember that many Texas policies exclude cosmetic hail damage, and that your deductible is yours to pay under Texas law.
Should flashing be replaced during a re-roof?
Yes, nearly always. A metal roof installed in Texas typically lasts 40 to 70 years; the 20-year-old flashing under it will not. Reusing old flashing makes it the weakest link on a roof built to outlast it, and most of it will not fit the new panel profile anyway.
On a standing seam metal roof we fabricate new eave trim, Z-closures, transition and headwall flashing to the exact rib height, and we cut new reglets for counter-flashing rather than reusing caulked pieces. The 2021 International Residential Code, which Dallas, Fort Worth and most DFW cities have adopted with local amendments, requires flashing at wall and roof intersections, at changes in slope and around roof openings; a re-roof is the moment to meet it properly. Aging skylights should be replaced at the same time, since re-flashing a 20-year-old unit is money spent twice.
How does Architectural Metal Panels handle flashing?
We measure, bend and install flashing with one crew, which is the difference between a part that fits and a part that is forced. Every piece is formed in our shop in Forney from the same coil and finish as the roof, so the color matches and fades at the same rate. Our team brings 26+ years of sheet metal experience to those details. Flashing is covered by our lifetime workmanship warranty, and we make metal coping and box gutter liners for the same buildings. Call (469) 569-3956 for a written scope.
Roof flashing questions DFW homeowners ask us
What is metal roof flashing?
It is shaped sheet metal, usually steel, aluminum or copper, installed where a roof meets a wall, chimney, valley or penetration. It laps under and over the roofing so water runs out instead of in. On metal roofs it is fabricated to the panel profile rather than bought off a shelf.
How long does roof flashing last in Texas?
Properly fabricated and lapped metal flashing typically lasts as long as the roof it is on, 40 years or more for painted Galvalume and longer for copper. Caulked joints and rubber pipe boots are the short-lived parts; expect to renew sealant every few years and rubber boots well before the roof wears out.
Can I just caulk a roof leak at the chimney?
You can, and it will usually leak again within a few seasons. Caulk shrinks and splits in DFW heat and UV. A chimney that leaks needs step flashing, a cricket and counter-flashing cut into the mortar; caulk is only the backup on top of that.
Does hail damage roof flashing?
Large hail can dent flashing and crease closures, and the wind that comes with it lifts counter-flashing and loosens boots. Dents that do not create ponding or open a joint are cosmetic. Have the flashing checked after any storm with hail larger than about an inch.
Should flashing be replaced when a roof is replaced?
Yes. New flashing costs little next to the roof, and old flashing rarely fits the new material. We fabricate new eave, valley, wall and chimney flashing for every re-roof and cut new counter-flashing reglets rather than reusing caulked pieces.
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Sources
Facts and figures on this page come from these references (checked October 2026):
- United Policyholders: Texas leads in hail damage for the 11th straight year — NICB and Verisk hail analysis
- Dallas hail insurance guide (2026) — yearly hail event counts for Dallas
- WFAA: 100-degree days in Dallas-Fort Worth — average count of 100°F days
- The Weather Network: Dallas UV index — summer UV levels
- Green Builder: can roof underlayments take the heat? — high-temperature membrane ratings
- Dallas Builders Association: City of Dallas adoption of the 2021 I-codes — code edition in force
- Texas Attorney General: contractor scams after hail storms — storm-chaser warning signs
- Metal roofing vs asphalt shingles for Texas homes (2026) — metal roof service life in Texas
Stop the leak at the joint, not with a tube of caulk
We will trace the leak, show you the flashing that failed and fabricate the right piece in our own shop. Call (469) 569-3956 or book online.
