How do I stop a metal building roof from sweating?

Sweating is condensation. Warm, moist air inside the building reaches the cold steel and turns to water. A vapor retarder facing on the warm side of the insulation stops that air from reaching the metal. Most metal building insulation facings test at 0.1 perm or less. If the facing is torn or missing, replacing it is the fix.

Should I re-sheet or coat an old shop roof?

Coat it if the panels are faded or lightly rusted but still solid, and the purlins are sound. Re-sheet it if the steel is rusted through, the panels are bent, or the insulation underneath is soaked and needs replacing anyway. A coating can't fix wet insulation, because the panels have to come off to reach it.

Does it cost more to re-roof a barn that was nailed?

Usually. One post-frame builder, FBi Buildings, says nailed steel takes 15 to 20 percent more labor to remove than screwed panels. Ask whether the quote assumes nails or screws on the old roof, and what goes back on. New panels are normally screwed.

Metal Building Roof in Midland, TX

Typical cost: screw-down panel roofs run $5 to $12 per sq ft installed in national guides; one post-frame builder puts a re-sheet at $1.50 per sq ft to strip screwed panels, $1.25 to hang new ones and $3.00 and up for the panels, with trim and screws extra
Garage-size roofs: about $2,000 to $5,200 in metal for a 400 sq ft two-car garage, and $4,200 to $10,900 for an 840 sq ft three-car
Time: HomeGuide puts a metal roof replacement at 1 to 5 days; a big shop with insulation work takes longer

Midland Metal Roofing refers your job to a crew that re-sheets shop roofs, barns and steel garages. Send the building size, panel type and what's going wrong, whether that's leaks, rust, sagging insulation or broken skylight panels.

Metal Building Roof Jobs Around Midland

Shops, barns and steel garages are everywhere in and around Midland. Their roofs fail in the same few places: screws, laps, insulation and the clear panels. The work splits along those lines.

Steel shop building with a new light gray ribbed metal roof and a roll-up door

Shop and Garage Roofs

A home shop or detached garage is usually a screw-down panel roof on wood or steel framing. The usual job is a full re-sheet after hail or rust, or new screws on a roof that is otherwise sound. HomeGuide's metal garage roof figures by size:

1-car (280 sq ft): $1,400 to $3,600
2-car (400 sq ft): $2,000 to $5,200
3-car (840 sq ft): $4,200 to $10,900

Old pole barn with faded red metal roof panels and light rust along the laps

Barns and Ag Buildings

Barns and pole buildings collect decades of wear. Painted panels from before the 1990s are often faded and chalky, and some older barns were nailed instead of screwed. Pulling nailed steel takes more labor, 15 to 20 percent more by FBi Buildings' estimate. Ask the roofer to check the purlins and trusses before quoting new panels, because new steel on a rotten frame won't last.

Crew lifting a long PBR metal panel onto steel purlins of a metal building, seen from behind

PBR Re-Sheeting on Steel Purlins

Pre-engineered steel buildings carry their roof panels on steel purlins rather than a solid deck. The code allows this when the panel is designed for spaced supports. Re-sheeting means removing the old panels a section at a time and screwing new ones into the same purlins. PBR is R-panel with a longer side lap, and our R-panel and PBR page compares the profiles. Ask for the panel gauge in writing. The Class 4 page explains why gauge matters in hail.

Underside of a metal building roof with white-faced blanket insulation draped over purlins

Roof Insulation and Liner Replacement

Most metal buildings use fiberglass blanket insulation with a facing that doubles as the vapor retarder. When that facing tears, warm, moist air reaches the cold steel and condenses. The water soaks the insulation and corrodes the panels from below. Re-sheeting is the cheapest time to replace it, since the panels are already off.

Facing rating: most metal building facings are Class I vapor retarders, 0.1 perm or less
Placement: usually on the warm (interior) side of the insulation; check the detail with your local inspector or designer

Translucent skylight panels set into a gray metal building roof beside a continuous ridge vent

Skylight Panels and Ridge Vents

Clear panels on a shop roof are plastic, not steel, so check them separately from the metal after every hailstorm. Replacement light panels have to match the steel panel's profile so the laps seal. Ridge vents and closures dry out as well. Ask whether the bid includes new closures and vent strips, or whether it reuses the old ones.

Roofer in a harness and wide-brim hat kneeling on a light grey standing seam roof, checking a seam

Why Midland homeowners call Midland Metal Roofing

Free quotes, no obligation to hire
Panel, gauge and price in writing before any work
Your request goes to one Midland roofer, not a call list
Homeowners never pay us for the referral

Re-Sheet, Retrofit or Repair a Metal Building Roof

How you fix a metal building roof depends on what has failed.

Leaks at screws only
a full screw swap is far cheaper than new steel. See metal roof screw replacement.
Chalky or lightly rusted panels on a sound frame
a coating may buy years. See metal roof coating.
Rusted-through panels, soaked insulation or hail holes
re-sheet, and replace the liner while the roof is open.
A large building where the work has to happen with the doors open
a retrofit roof over the old one keeps the inside dry. Our commercial metal roofing page covers retrofit framing.

If the building is also your home, a barndominium roof has different needs. See barndominium metal roofs. For a new building, HomeGuide's $20 to $50 per sq ft for an installed prefab metal building doesn't include insulation. Ask what it would cost to add.