Does a metal roof need maintenance?

A metal roof does need maintenance, but not much: a yearly look and gentle cleaning, clear valleys and gutters, and a check of the screws, seams, flashing and sealant. McElroy Metal, a panel maker, says a thorough cleaning and inspection once a year is about all a metal roof requires.^[1] The catch is that most of that work happens on the roof itself, so the practical plan for a homeowner is to watch from the ground, keep records, and have a roofer do the rest.

How often

Sheffield Metals, a metal supplier, says a home in a milder climate might need surface maintenance only once a year or every 18 months, while a roof in the shade or under trees may need it more often.^[2] It adds that it is common practice to have professional structural maintenance done at least once every two years.^[2] If your roof sits under oaks or pines, as many Virginia roofs do, plan on more frequent visits than an open roof would need.

Read your warranties before you set a schedule: some warranties list required maintenance to keep the warranty valid.^[2] Also plan a check after any storm that drops branches or hail on the roof.

What a roofer checks

Flashing and penetrations. These are where most metal roofs leak. Pipes, chimneys and vents are protected by flashings, boots or collars that should be intact, secure and not cracked,^[1] and UV rays break down rubber flashings such as vent pipe boots over time.^[2]

Screws on a screw-down roof. McElroy explains that because metal continually expands and contracts, screws can come loose,^[1] and it recommends having all screws replaced by a professional every 25 to 30 years.^[1] Sheffield notes that the EPDM washers on gasketed screws break down from UV exposure over time, and that replacing the fastener may be the best fix.^[2] Standing seam roofs hide their clips, so this matters less there.

Seams and panels. Sheffield says seams should be checked to make sure the panels have not loosened or moved and that enough space has been left for thermal movement.^[2]

Sealant. Some sealants last a long time, but others need to be touched up or replaced in spots.^[2]

Valleys, gutters and debris. Debris and water collect in valleys, and leaves left there can stain or scratch the paint.^[1][2] Sheffield warns that clogged gutters and drains create standing water that can cause premature corrosion on nearly every metal roof material.^[2]

Things that damage a metal roof

Trees. Sheffield notes that branches touching the roof can scratch or scuff the paint, which is typically not covered by a paint warranty.^[2] Keep limbs trimmed well back; for big trees, hire a tree service.

Other metals and materials. According to Sheffield, Galvalume performs best when not in contact with copper, bricks, treated lumber, iron and concrete.^[2] Watch for runoff too: Metal Sales notes that condensate from air conditioning units typically contains dissolved copper,^[5] so an AC line that drips onto the roof should be rerouted.

New holes. Satellite dishes, solar mounts and vent pipes added later are common leak points. Sheffield advises that any penetration added to a metal roof should be handled by a professional roofing contractor,^[2] not by the satellite installer or a plumber.

Cleaning, and what not to use

Metal Sales' care guidance says plain water from a hose or pressure sprayer is often adequate, with a mild detergent solution and a soft brush or cloth for heavier dirt.^[4] It is firm on one point: "Do not use wire brushes, abrasives, or cleaning tools which will scratch the coating surface."^[4] Sheffield's list of things never to use on a metal roof is longer: steel wool, wire brushes, sandpaper, high-pressure power washers, scouring powders, paint removers and paint thinners.^[3] Because the two makers differ on pressure spraying, ask whoever cleans your roof to follow your panel maker's own care guide.

Cleaning is not only cosmetic. Sheffield notes that most metal roofing paint warranties do not cover excessive chalking in the presence of pollutants,^[3] which is a reason to keep the surface clean. For scratches, touching up paint without following the manufacturer's recommendations can make a blemish worse or void the warranty.^[2]

What you can do from the ground

• Look the roof over with binoculars in spring and fall for screws standing proud, lifted trim, scratches, rust spots or debris in valleys.
• Check the attic and top-floor ceilings for stains after a hard rain.
• Keep gutters flowing; see how often gutters should be cleaned.
• Keep the paperwork. McElroy advises owners to keep records of everything, from the installation to every maintenance or inspection visit and repair,^[6] which helps if you ever file a warranty claim.

For a fuller ground-level checklist, see how to check a roof for damage from the ground and how often a roof should be inspected.

When to call a licensed pro

Call a roofer for the yearly or two-yearly inspection, for cleaning the roof surface, and any time you see loose screws, lifted panels, damaged flashing, rust or a leak. Roof work is dangerous: Falls are the leading cause of work-related injuries and deaths among roofers,^[7] and Sheffield warns that metal roofs are very slippery when wet.^[2] In Virginia, roofing contracting is the licensed specialty for repairing the materials that form a watertight, weather-resistant roof surface.^[8] Check a roofer using DPOR's License Lookup or by calling (804) 367-8511.^[9] If the roof is still under the installer's workmanship warranty, call that installer first.

If you are hearing noises or seeing leaks, read why a metal roof makes popping noises and why a metal roof leaks at the screws, or browse more exterior answers and metal roof repair. Loclis lists licensed businesses from Virginia's DPOR register, including exterior contractors in Blacksburg.

Book a metal roof inspection or repair, and licensed local roofers send quotes or offer an estimate visit.