Applications

Built for Working Steel Roofs

Steel roofs fail from the outside in. Galvanizing wears thin on panel ribs and cut edges, red rust blooms around every fastener, and once water finds a corroded screw hole it follows the purlins to places that have nothing to do with where the stain shows up inside. MetalGuard interrupts that sequence with a rust-inhibiting, fully waterproof membrane applied over the existing panels.

Where we do most of our work:

Warehouses and distribution buildings with R-panel or PBR screw-down roofs — thousands of fastener penetrations per roof, every one a future leak.
Manufacturing plants, where interior downtime costs more than the roof itself. Coating work happens overhead while production keeps running.
Agricultural buildings — pole barns, machine sheds, livestock housing where ammonia and condensation chew galvanizing from both sides.
Older galvanized and Galvalume roofs that are structurally sound but visibly rusting at laps and eaves.

Steel panel roof restored with elastomeric coating

Prep: Where Steel Jobs Are Won

On steel, preparation is the whole ballgame, and it scales with corrosion grade:

Light surface rust: pressure wash, power-tool clean loose oxide to a tight surface, then spot-prime rusted areas with a rust-converting primer before the membrane goes on.
Established rust at laps and fasteners: wire-wheel to sound metal, replace any fastener that will not seat tight — oversized screws with new EPDM washers — and brush-grade detail every lap before spraying.
Perforated panels: individual panels can be patched or replaced and coated into the system; if more than a small fraction of the field is perforated, we will tell you the roof is a replacement candidate, not a coating candidate.

Degreasing matters more on steel than any other substrate — years of flue exhaust, ag dust or forklift-bay film will defeat adhesion invisibly. Every MetalGuard job spec includes a solvent-wipe verification on test areas after washing.

Timing the Work

Surface temperatures between 50°F and 120°F, above the dew point, with a dry surface. On dark steel that usually means starting early and chasing the sun around the roof in summer. Because the membrane goes tack-free in seconds, pop-up storms rarely cost more than the spray time lost — a real advantage over slow-curing acrylics that wash off in an afternoon shower.

Why Not Just Repaint?

Paint is a cosmetic film measured in single-digit mils; it follows every crack in the substrate. This system builds 40 to 60 mils of elastomeric membrane with 400% elongation — it bridges seams and moving laps instead of telegraphing them, and it carries a real waterproofing warranty, which paint never does.