An office roof fails at the parapet. Wind drops snow behind the wall, the drift grows deep and the drain sits in the middle of it. The thaw sends water to a drain that is buried or frozen. In Flagstaff, AZ, where winter snow runs near 90 inches or more, that is the pattern to watch on any parapet-edged office roof.
Book the walk ahead of the first big snowfall. Hand over the building address, the membrane or panel type and the date anyone last walked the roof. We book the sag and drain checks, then write the tenant note.
An office roof with a low slope and a parapet traps drifts by design. The parapet keeps people safe and keeps snow in. A drift behind it can reach feet deep after a big storm. One February 21, 2019 day dumped 35.9 inches, a single-day record. Once the February 28, 2023 storm passed, the city's overload checklist opened with drooping ceilings, bent trusses and leaks that grow worse by the day.
Brown rings on a January ceiling can come from a frozen drain or a pulled edge as easily as a torn membrane. It may be a leak, a frozen drain or a structural flag. We check all three. A ceiling that sags or a door that jams means a structural call comes before any shoveling.
Weight counts at the roof edge too. A cornice of ice can hang off an eave and pull the edge metal with it. We check metal edges for bends and loose fasteners after each big storm, because a pulled edge lets water behind the sheet.
Downtown, the Railroad Addition Historic District is full of old commercial buildings, among them the Babbitt Brothers Building and the Riordan Building. Offices also sit along Butler Avenue and near the I-40 exits. The age and construction vary, and so do the roofs.
Older brick offices usually carry parapets, and many have been patched more than once. Newer offices tend toward single-ply membranes and rooftop units. A clinic suite inside an office building adds equipment and hours that a medical office roof plan handles. An office wing joined to a hospital needs hospital roof rules for noise, fumes and access.
Walk the parapets. Look at coping caps, counterflashing and sealant joints. A thin gap at the cap draws water into the wall, and a freeze spalls the brick face. Check each drain and overflow scupper; roof drain service covers clearing and resetting both. Test flow. Clear grit. Find the drift lines on the plan.
Then check rooftop units and vents. Each has a curb and a flashing. Snow packs on the lee side and refreezes. Look for loose panels, cracked sealant and ice-damaged lines. A leak at a curb can run along the deck and show up far away, so a moisture scan helps trace it.
Look at the interior as well. Water stains on a ceiling, a damp corner or a musty smell tell you where to look on the roof. Photograph them with the date. Compare the pattern with the drift lines and drains. Lay the interior stain map over the roof plan and the source usually shows itself.
Melt loads an office roof in March, and monsoon cells load it again in July and August, when roughly a third of the yearly water arrives. Summer storms test flashings. Winter melt tests drains and edges. Freezes return by late September and can reach minus 30 degrees F.
Each thaw builds ice along the eave. Water runs under snow, reaches a cold eave and freezes. That ridge of ice dams the next melt. On a downtown office with a sidewalk below, falling ice is a safety risk too. Snow guards, heat cable and a regular clearing routine reduce it. We look at the edge detail and fix the cause.
Plan the repair season too. Dry weather is short at 7,000 feet, and the window from late spring to early fall is when welds, adhesives and sealants cure best. Book the work early, and keep a temporary seal on hand for the weeks when weather does not cooperate. Leaks that start in winter get a temporary fix and a permanent one in summer.
Decide on snow removal before the storm lands. Pick the people who go up, and give them plastic shovels. Drains and the deepest drift behind the parapet come first, and the removal stays symmetric so one side never carries extra weight. Fall protection is required for anyone near the edge. Over a public sidewalk, block off the pavement below before the first shovelful.
Roof repair around tenants needs notice. Tell them what will happen, when and who to call. Loud work moves to early hours or weekends if leases allow. Keep entrances and parking clear. Protect air intakes from fumes. Tenants who know the plan call less often.
Parking and deliveries need a plan. Staging a lift or a dumpster takes spaces tenants use. Agree on a spot with the manager, and keep fire lanes open. Keep a single contact for tenants during the work. That person answers calls, passes along notices and reports any delay the same day.
Curbs, open seams and parapet flashings get fixed before anything else. Wet insulation that spreads across big areas points to commercial roof replacement, and the infrared moisture survey plus core samples draw the boundary. A coating can extend a dry, sound roof, but it cannot fix wet insulation or a sagging deck.
On historic buildings, work with the building's features. Use materials that suit the walls. Keep parapet details true. Take photographs before and after. A repair that harms old brick costs more than the leak it fixed.
Insulation is the quiet cost. At replacement, adding board is cheap compared with doing it later, and the city's adopted energy code, the 2018 IECC with local amendments, sets the minimum R-value. We confirm the requirement with the building official, and the scope states what was assumed.
Walk every office roof in fall and again after the spring thaw. Fix parapet gaps, clear drains and log every leak. Rank roofs by age, snow exposure and tenant impact. Owners with buildings on Butler Avenue and Lone Tree Road and downtown should hold the same file for each building. Then book the walk before snow.
Keep a one-page summary per roof: type, age, last walk, open items and next step. Tenants and lenders ask for it.
Melt finds gaps that snow had sealed. Ice at eaves backs water under edge metal, and buried drains overflow. Check parapet flashing, edge details and drains, then fix the cause instead of sealing the stain.
Give the date, the location, what was done and what comes next. We provide photos and a short written summary. Clear notes reduce repeat calls and protect the manager's relationships.
It can be. Ice and snow sliding off a roof can land on sidewalks and entrances. Snow guards, heat cable and a clearing routine help. Close the area below before anyone clears the roof.
Use materials that suit the brick, keep original parapet lines and take dated photos before and after. Follow any preservation rules that cover the property. Thick sealant smeared across aged masonry joints does harm.
Go to replacement when wet insulation spreads across large areas, seams open in rows or the same spot leaks after each repair. An infrared scan plus a few cores settles it.
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.