Side Laps Opening Up
- You See
- Gaps and dirt streaks along laps that run up the slope.
- What It Means
- Daily expansion works stitch screws loose until the lap lifts. Laps get re-stitched, sealed, and covered with fabric embedded in the base coat.
Commercial Metal Roofs
Louisville Commercial Metal Roof Coating
Our commercial metal roof coating work in Louisville covers exposed-fastener, standing seam, and corrugated roofs on warehouses, shops, and retail buildings, after rust, screws, and laps are repaired.
- Every Screw Checked
- Rust Graded First
- Fabric At End Laps
- R-Panel And Standing Seam
- Red And White Rust Treated
- Laps Sealed With Fabric
- Photos Before Panels Disappear
Is This Metal Roof Ready For Coating?
Coating fits steel that still holds a screw. Each row is a condition we find on Louisville metal roofs, and the dots show which job it points to.
- Usually fits
- Sometimes
- Rarely
| What We Find | Coat Now | Repair, Then Coat | Replace Panels |
|---|---|---|---|
| Faded paint, tight lapsWash, adhesion test, then prime and coat. | Coat Now | Repair, Then Coat | Replace Panels |
| Screws backing out, cracked washersFasteners tightened or upsized, then capped. | Coat Now | Repair, Then Coat | Replace Panels |
| Orange bloom on panel facesWire brushed and primed with a rust inhibitor. | Coat Now | Repair, Then Coat | Replace Panels |
| Flaking scale and pinholesGround to firm steel, holes patched before coating. | Coat Now | Repair, Then Coat | Replace Panels |
| Panels rusted through or flexing underfootThose panels come out, and coating waits on new steel. | Coat Now | Repair, Then Coat | Replace Panels |
Most roofs show three of these rows in different sections, so the plan is drawn section by section.
Where Commercial Metal Roofs Start Leaking
Panels rarely fail first. Water gets in at the joints and the hardware, and these are the spots we open up before coating.
Rusted Screw Heads And Washers
- You See
- Rust rings around screws and rubber washers dried out and split.
- What It Means
- Water follows the threads past a failed washer. Rusted heads get swapped for oversized screws with new washers, then capped with sealer.
Leaks At Curbs And Pipe Penetrations
- You See
- Stains under exhaust fans, vent stacks, and rooftop unit curbs.
- What It Means
- Penetrations are flashed into the panels with sealant that ages faster than steel. Each one is resealed with fabric before the field coat covers it.
Torn Closures Under Ridge Caps
- You See
- Foam closure strips crumbled or missing under the ridge cap.
- What It Means
- Wind-driven rain blows in where closures are gone. Torn closures are replaced and ridge cap overlaps get sealer and fabric.
Drips From Condensation Under The Deck
- You See
- Water on purlins and insulation facing, even after dry days.
- What It Means
- Warm, moist inside air condensing on cold steel can look like a leak. We check for it from inside so the real cause gets fixed.
Chalking Factory Paint
- You See
- Colored powder on your hand after wiping a faded panel.
- What It Means
- Heavy chalk blocks adhesion. It is washed off with a cleaner the coating maker approves, then a test patch shows whether primer is needed.
Commercial Roof Coating Options for Louisville
Three ways we coat a metal roof, chosen by slope, standing water, and what the building needs underneath.
Silicone Over A Rust Primer
Holds up where water sits after rain on low-pitch panels and in box gutters. It gathers dirt over time, and later recoats need silicone or a special primer.
Best on: Low-slope metal, additions, box gutters
Acrylic Over A Rust Primer
Water-based and bright white, it suits sloped R-panel that drains fast. Acrylic needs warm, dry hours to cure and recoats easily when the topcoat wears.
Best on: Sloped exposed-fastener roofs
Spray Foam Plus Coating
Foam fills the panel ribs to a smooth surface and adds insulation, then a coating protects it from sun. Short curbs get raised before spraying.
Best on: Heated or cooled space under the metal
Benefits of Coating Your Roof
Four reasons owners coat solid steel instead of re-paneling it.
Joints That Stay Sealed
An elastomeric coating stretches as panels grow and shrink each day, so it stays bonded over laps where a thin paint film would split. Fabric at end laps carries the heaviest movement.
Budget Goes Into Repairs
Money that would buy new panels goes into fastener work, rust treatment, and lap repairs on the roof you already have. Rust level and screw count set the final number.
Rust Slowed Under The Coat
Primed steel sealed under a continuous coating stops taking on rain and dew. Surface rust that was ground back and primed has far less water feeding it.
Recoat Later, Skip Tear-Off
When the topcoat wears thin, the roof is cleaned and recoated with a compatible product. That keeps old panels and insulation out of the landfill for another cycle.
Rust Spreading Along The Ribs?
Photograph the worst panel and the screw heads around it. Those two details tell us most of what the prep will involve.
Our Commercial Metal Roof Coating Process In Louisville
Metal prep takes most of the time on the roof. Coats go on after every lap and screw has been dealt with.
- INSPECT
Step 1: Inspect Your Roof
We grade rust panel by panel, count loose and stripped fasteners, measure laps and ridge cap, and check purlins from inside. A fabric-strip pull test shows whether the factory paint will hold a coating.
- WASH
Step 2: Clean The Steel
Dirt, chalk, and oil come off with a pressure washer and an approved cleaner. Panels dry fully before any primer, and dew on north slopes pushes the start time back.
- PRIME
Step 3: Grade And Prime Rust
White rust is washed and primed per the coating maker. Light red rust gets wire brushed, and heavy scale is ground to firm metal and patched where pinholes go through.
- DETAIL
Step 4: Rebuild Fasteners And Laps
Every screw row is tightened by feel, stripped holes get oversized screws, and end laps get stitch fasteners where missing. Sealer and polyester fabric cover each joint.
- COAT
Step 5: Coat The Field
Base coat and topcoat go over the whole roof at the film thickness the data sheet lists for metal, with skylight panels masked so they keep passing daylight.
Other Coating Systems We Install
Metal roofs often sit beside other roof types on one building. These are the systems we bring for those sections.
Silicone Roof Coating
For a flat addition or box gutter that holds water beside the sloped metal.
See Silicone Roof CoatingSpray Foam Roofing
When the building below is heated and the bare metal adds little insulation.
See Spray Foam RoofingShingle Roof Coating
Shingle mansards on the same storefront get checked against the shingle maker's guidance.
See Shingle Roof CoatingQuestions About Coating Metal Panels
Answers for owners comparing a coating with paint, patches, or new panels.
Question about your own roof?
Call UsIs coating a metal roof different from painting it?
Yes. Paint is a thin decorative film that cracks along moving laps, while an elastomeric roof coating goes on many times thicker and stretches as the steel grows in afternoon sun and shrinks overnight. Coating systems also add seam sealer and reinforcing fabric at laps, two details a paint job leaves out.
Can a coating stop an active leak on a metal roof?
Yes, when the leak comes through a fastener, a panel lap, or a small rust pinhole and that spot is repaired before the field coat. We trace stains on purlins and insulation from inside, mark the matching screw or lifted lap on top, then repair, prime, and seal it. A split gutter seam or rusted-through panel needs hands-on repair first.
What is the difference between red rust and white rust on metal panels?
Red rust is iron oxide on steel that has lost its zinc or paint, while white rust is powdery zinc corrosion on the galvanized layer. White rust is washed off and primed. Light red rust is wire brushed and primed, heavy scale is ground to firm metal, and pinholed panels are patched or replaced.
Will a white metal roof coating need review in a Louisville preservation district?
If the building sits in a Louisville Metro Preservation District or Overlay Zone and the roof shows from the street, plan on it. Exterior changes there go to Planning and Design Services before the building permit.
Metal behind a parapet rarely shows, while standing seam slopes and awnings facing the sidewalk do, and cool-colored coatings give reviewers an option beyond white.
Do standing seam roofs coat differently from exposed-fastener roofs?
Yes, the prep differs. Standing seam has no screws through the field, so leaks start at end laps, clips, and curbs. We seal end laps and penetrations, check that clips still let panels move, and coat over the seams. Exposed-fastener R-panel needs every screw and washer handled first.
Ready To Stop The Rust On Your Metal Roof?
Send the roof size and where it leaks. We will walk the panels, photograph every problem spot, and tell you whether coating fits.