An exposed-fastener metal roof leaks at its screws. Every freeze-thaw cycle moves the panels a little, and every move loosens a screw. In Flagstaff, AZ that adds up fast. The record low is minus 30 degrees F, freezing temperatures return in late September, and sun at 7,000 feet heats the same panels by afternoon. The washers dry. The holes widen.
Commercial Roofing Flagstaff retrofits and restores metal roofs. We start with the screws and the structure, and we say plainly when the panels should come off.
The cost of waiting is water. A loose screw lets water into the insulation, the purlin and the ceiling below. The stain shows long after the damage begins. A walk in early fall finds the screws that need work while the roof is dry.
A retrofit keeps the old roof as a base and adds a new weathertight layer over it. A restoration repairs and recoats what is there. Both avoid tear-off, which saves disposal and keeps the building dry. Both depend on the old roof being sound enough to hold the new work.
Exposed-fastener panels are screwed through the face into purlins. Each screw has a washer that seals the hole. Over years the washers fail and panels move. Sealant at laps and trim dries and cracks. Rust starts at cut edges and fastener heads.
We check all of that before we pick a path. The choice runs from fastener replacement and sealant to a full retrofit with new panels over framing.
Corrosion shapes the decision. Light surface rust at cut edges can be treated and sealed. Rust that has eaten through a panel cannot be patched with a coating. We probe rusted spots and mark those that have lost metal. The count tells us whether to treat, patch or replace.
Walk the roof and count the bad screws. A good screw sits flat with the washer slightly squeezed. A bad one is raised, tilted, rusted or ringed with stain. If the count is low, replace them. Use oversize screws with new washers where the old holes have widened. Seal laps and trim.
If the count is high on many panels, the holes in the purlins may be worn too. New screws then do not bite. Fasteners that miss the purlin do nothing. At that point, screws are a patch, and the roof is nearing retrofit or replacement.
We log the count by panel run and photograph the worst areas. A seam failure repair and a flashing failure repair are part of the same visit.
Trim and flashing need the same care as the field. Ridge caps, eave trim and wall flashings all use screws and sealant. They catch wind and move with heat. We replace failed pieces and reseal the joints. A loose ridge cap catches wind and acts as a lever on the panels near it.
A retrofit adds new panels, framing and sometimes insulation over the old roof. That adds weight. Flagstaff takes 90 inches or more of snow in a normal year. Late February 2023 added 24.5 inches in places, and the city tied several roof collapses to snow load.
Framing gets checked before any new panel is ordered. We read the purlins, trusses, ceiling lines and old panels. We ask for records. A sagging ceiling, a bowing truss or a door that sticks is a flag. If we see one, the owner calls a structural engineer before any retrofit.
Rusted or bent purlins fail the check. In that case, tear-off and repair of the framing is the sound path.
Insulation and condensation come into the retrofit decision. A metal roof over a warm, humid space drips from the underside in cold weather. A retrofit can add insulation and an air gap to cure that. A coating cannot. We read the stain pattern against the weather before we choose.
Three paths cover most retrofits. One adds a framing system over the old panels, with new standing seam panels on top. Another adds a spray or fluid coating system over a sound, clean panel. The third lays insulation and a membrane over the old roof where the slope and the structure allow.
The framing path suits roofs with low slope and weak seams. It adds a clear air gap and a new, hidden-fastener skin. It costs more and adds weight. A standing seam metal roofing panel is the usual cap.
The coating path suits roofs with sound panels and tight screws. A silicone roof coating or an acrylic roof coating seals the surface and the fasteners. We prep the metal, treat rust and seal every lap and screw first.
Snow retention may be needed after a retrofit. A smooth new skin sheds snow faster than an old, rough one. Guards go above walkways, doors and equipment. The sag check and the snow plan go into the scope.
Coatings and sealants need dry, mild weather. Metal work here has a warm window, late spring to early fall. Afternoon monsoon storms in July and August cut the dry hours, and the monsoon brings a third of the yearly moisture. We time prep and coating days around forecasts.
Freeze-thaw acts on any pinhole. Water gets in, freezes and lifts the film. Prep matters more than the product. The panel must be clean, dry and primed. Rust must be treated. We seal first and coat second.
Frost on metal in the morning blocks a bond. We wait for the surface to clear and test with a moisture meter.
Rust treatment is slow. The panel must be cleaned to bare metal at rust spots, treated and primed before sealant or coating goes on. Skipping it lets rust creep under the new film. A good prep day is the difference between a coating that lasts and one that blisters.
Metal roofs cover shops, warehouses, barns and outbuildings. Williams, 42 miles west on I-40, logs about 65 inches of snow a year, and Bellemont sits higher than Flagstaff at roughly 7,100 feet. Distance adds hauling, so parts and deliveries get planned before the crew leaves town.
A metal-roofed shop or warehouse in Bellemont gets the same fastener count and framing check as one in town. An older warehouse roofing job runs through the same checks: fasteners, structure, drains and a snow plan.
If few are bad, yes. Use oversize screws and new washers, and seal laps and trim. If many are loose and the purlin holes are worn, new screws will not bite. Plan on a retrofit or replacement.
Framing, panels and sometimes insulation add dead load that stacks with snow. We check purlins, trusses and records first. If we see a structural flag, call a structural engineer before any retrofit.
Only if the panels are sound and the screws are tight. We treat rust, seal every lap and screw, then coat. A coating over loose screws hides the problem.
When rust has eaten through, panels are bent or purlins are damaged. Tear-off and framing repair are the sound path in that case.
No. Frost and cold block the bond. The roofing season runs late spring to early fall. We plan around the forecast and stop if conditions slip.
Browse the services, roof systems and building types we work with across Flagstaff and nearby Arizona communities.
A walk of the roof with photos, findings and a written scope.
Active leaks, storm damage and blocked drains get a fast response.
Roofing across Flagstaff and nearby Arizona communities.