At a glance: Completed 2026-09-10: shingle-to-metal roof transition repair on Coachlight Place, Saint Joseph, MO 64503. Office: Kansas City, 816-572-9500.
Where two roofs meet, water looks for a way in
Plenty of homes in St. Joseph have a metal roof over a porch, addition or carport that butts into a shingled main roof. Each material sheds water well on its own. The weak spot is the seam between them. Metal panels have ribs and seams that channel water in lines, while shingles shed it in overlapping layers, and when the two meet without the right flashing, water runs straight into the joint.
On Coachlight Place, the original transition had been built without enough overlap, and rain was getting under the shingles at the bottom edge of the main roof and running onto the porch ceiling.
Opening the bottom two courses
The crew removed the bottom two courses of shingles along the transition. That exposed the old flashing and the top edge of the metal roof so the crew could see how the joint had been built and where water was getting in. Two courses is enough to get full-width flashing in underneath without disturbing more of the roof than needed.
Eighteen inches of new coil flashing
New flashing was bent on site from brown coil stock. It runs 18 inches up the shingle slope, under the shingles, then turns down over the top of the metal panels. That generous upslope leg is the key to the repair. Even if wind drives water up under the shingles, it hits metal flashing long before it reaches the top of the flashing, and it gets turned back out onto the metal roof below. Brown coil was chosen to blend with the Driftwood shingles and the bronze tone of the metal.
Ice and water shield and butyl tape
Under the flashing, the crew installed ice and water shield over the transition, lapped onto the metal. Then butyl tape was set between the metal panels and the new flashing. Butyl tape stays flexible for years and seals the ribs of the metal so wind-blown rain cannot travel sideways under the flashing. Layering membrane, tape and metal gives the joint three separate lines of defense.
Driftwood shingles back in place
New Owens Corning Duration shingles in Driftwood were installed over the flashing to match the existing roof. The courses were lined up with the shingles above so the repair is hard to spot from the yard. Duration's wide nailing zone helps keep nails high and out of the flashing area, so no fasteners punch through the metal where water runs.
Fixing the siding at the porch
Where the transition meets the wall near the porch, one piece of 4-inch Dutch lap vinyl siding had been damaged by the leak and by previous patch attempts. The crew replaced it with a matching white Dutch lap piece so the wall looks finished and the flashing behind it is covered properly. Siding and roof flashing work together at walls, so it made sense to handle both in one visit.
Why caulk was not the answer
The most common quick fix on a leaking transition is a bead of caulk or roof cement along the seam. It might stop the drip for a few months, but metal moves with the temperature, and the caulk cracks. Rebuilding the joint with proper flashing is the repair that lasts.
Roofer near me in St. Joseph, 64503
If you are searching roofer near me in St. Joseph, our Kansas City crews serve 64503, 64505, 64506 and the rest of Buchanan County. We repair shingle, metal and low-slope roofs and the transitions between them, and we handle siding and gutter details along the way.
Call 816-572-9500 or 1-800-564-6232 any time of day.
Lifetime workmanship warranty
The flashing repair on Coachlight Place is covered by our lifetime workmanship warranty. If the transition we rebuilt lets water in, we come back and make it right.
How to spot a failing transition
Inside, look for stains on the porch or addition ceiling right below where the two roofs meet, or for peeling paint on the beam under the joint. Outside, rust at the top edge of the metal panels, shingles that curl up at the bottom of the main roof, or old caulk smeared along the seam are all warning signs. In winter, ice that builds up at the transition can push water back up under shingles, which is another reason the long flashing leg matters in northwest Missouri.
Metal and shingles expand differently
Metal panels can grow and shrink noticeably between a cold January morning and a hot July afternoon, while shingles barely move. A rigid seal between the two eventually tears. The approach on Coachlight Place, a loose lap of flashing over flexible butyl and membrane, lets the metal move under the flashing without opening a gap. That is why this kind of repair holds up through St. Joseph's wide temperature swings.
Porch roofs on 64503 ranch homes
Many one-story homes in the south end of St. Joseph had metal porch or patio roofs added years after the house was built. Those add-ons often tie into the main roof with a short piece of flashing and a bead of sealant. If yours was added later, it is worth a look before the next heavy rain.
What the crew did, step by step
- Removed the bottom two courses of Driftwood shingles along the shingle-to-metal transition.
- Installed ice and water shield over the transition, lapped onto the metal roof.
- Set butyl tape under the new flashing to seal the metal panel ribs.
- Installed brown coil flashing 18 inches up under the shingles and down over the metal.
- Reinstalled Owens Corning Duration Driftwood shingles over the flashing.
- Replaced a damaged piece of white 4-inch Dutch lap vinyl siding at the porch.
- Cleaned up and hauled away all debris.
Questions homeowners in Saint Joseph ask about this repair
Why does my roof leak where shingles meet metal?
The joint usually lacks enough flashing overlap, so water runs into the seam. Rebuilding it with long upslope flashing fixes it.
How far should flashing go under the shingles?
On this repair we ran it 18 inches upslope, which keeps wind-driven water from reaching the top edge.
What is butyl tape used for on a metal roof?
It seals between metal panels and flashing and stays flexible as the metal expands and contracts.
Can you match Owens Corning Driftwood?
Yes. Driftwood is a current Duration color.
Do you do roof repair in St. Joseph?
Yes. Call our Kansas City office at 816-572-9500.
Do you fix siding too?
Yes. We replaced a piece of Dutch lap vinyl siding as part of this repair.