In this article 13 sections
- Can You Coat a Rusted Commercial Metal Roof?
- Restore or Replace? Check the Rust First
- The Restoration Process, Step by Step
- Cost of Metal Roof Restoration
- Acrylic or Silicone on Metal?
- FAQs | Metal Roof Restoration
- Should I replace all the screws on a metal roof?
- Does coating stop rust from spreading?
- Can you coat a metal roof with holes?
- Does coating a metal roof reduce noise?
- How long does a metal roof restoration take?
- Is a coated metal roof slippery?
- Get a Metal Roof Restoration Assessment
Can You Coat a Rusted Commercial Metal Roof?
Most leaks on older metal buildings come from fasteners and seams, not the panels. Here’s how a restoration works and how to tell if your roof qualifies, from our metal work across commercial roofing in San Antonio.
Restore or Replace? Check the Rust First
| Condition | What you see | Typical path |
|---|---|---|
| Surface rust | Orange staining, metal solid when probed | Restore with coating |
| Scale rust | Flaking layers, metal still solid underneath | Wire-brush, prime, restore |
| Perforation in spots | Pinholes or small holes | Replace or patch affected panels, then restore |
| Widespread perforation | Holes across many panels, soft metal | Replace panels or install a retrofit roof |
As with any coating, when more than about 25% of the roof needs repair or the insulation below is wet, replacement usually makes more sense.
The Restoration Process, Step by Step
- Inspect panels, fasteners, seams, flashings and gutters; probe rust areas.
- Clean with a pressure wash to remove dirt, chalking and loose rust.
- Treat rust by wire-brushing scaled areas and applying a rust-inhibiting primer.
- Fix fasteners: replace stripped or backed-out screws with the next size up, and seal or cap the rest.
- Seal seams and laps with mastic and reinforcing fabric.
- Repair or replace perforated panels, skylights and flashings.
- Apply the coating (acrylic or silicone) at the specified thickness.
Oversize replacement screw guidance: SFS.
Cost of Metal Roof Restoration
| Item | Typical cost |
|---|---|
| Full restoration system | $3 – $9 / sq ft |
| Acrylic coating (material + labor) | $0.50 – $2.00 / sq ft |
| Silicone coating (material + labor) | $1.50 – $4.50 / sq ft |
Core Commercial Roofing (2026); Roofr (2026). Rust treatment, panel replacement and fastener work move the price within the range.
Example: a 20,000 sq ft metal warehouse at $3 to $9 per sq ft comes to about $60,000 to $180,000, versus a much higher cost for a new metal roof.
Acrylic or Silicone on Metal?
On sloped metal roofs that drain well, acrylic is usually the value choice. Where there are low-slope sections, ponding or long exposure, silicone holds up better. See silicone and cool roof coatings.
For damaged roofs, see metal roof repair and restoration, commercial metal roofing in San Antonio and metal building roofing.
FAQs | Metal Roof Restoration
Should I replace all the screws on a metal roof?
Not always. Stripped, loose or rusted screws get replaced with oversized screws, while sound ones can be sealed or capped as part of the coating system.
Does coating stop rust from spreading?
A properly prepared and primed coating seals out moisture and oxygen, which slows or stops further rust on the coated surface. It won’t fix metal that’s already rusted through.
Can you coat a metal roof with holes?
Small holes can be patched with reinforced mastic or metal patches before coating. Large perforated areas need panel replacement first.
Does coating a metal roof reduce noise?
Slightly. A coating adds a thin layer that can dampen rain noise a little, but insulation makes a much bigger difference.
How long does a metal roof restoration take?
Often a few days to a couple of weeks depending on size, rust treatment and weather. The building usually stays in use.
Is a coated metal roof slippery?
Silicone-coated metal is slippery when wet, and sloped roofs more so. Use fall protection, and add walkway areas where people need regular access.
Get a Metal Roof Restoration Assessment
We’ll probe the rust, check fasteners and seams, and tell you whether restoration or replacement is the better value, with pricing for both.
- Free roof assessment across San Antonio, including Westover Hills, Converse and roof repair in Alamo Heights
Book your free roof inspection in San Antonio or see commercial roof coatings in San Antonio.
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