Fort Collins commercial roof repair for small-building owners

The buildings this page covers

Commercial roof repair in Fort Collins, for the purposes of this guide, means small buildings: the brick storefronts on College Avenue, Linden and Walnut in Old Town, the strip centers along College, Harmony and Drake, one- and two-story offices and clinics, churches, light-industrial flex buildings and shops on the east side of town, taprooms and studios in older industrial buildings north of downtown, and the apartment complexes around CSU that have flat or low-slope sections over breezeways and stairwells. Almost all of them have a membrane roof, a few have low-slope metal, and many have rooftop heating and cooling units.

This site is a free guide for owners and property managers, not a roofing company. Estimate requests go to an independent local roofing contractor partner. For membrane work, ask before the visit whether the person coming out repairs low-slope roofs regularly. A large distribution or manufacturing roof is a job for a firm that does nothing else.

Hail: the main event for a Fort Collins flat roof

From May through August, storms build over the foothills in the afternoon and push east across the city. On a house, hail bruises shingles. On a commercial roof the damage is often harder to see and easier to argue about later.

• TPO can crack or puncture under large hail, especially once the sheet has aged and lost flexibility. Small fractures can be close to invisible until they leak.
• EPDM tends to flex and shrug off smaller stones, but older, shrunken rubber can split, and hail can crush the insulation board underneath so the membrane sits in a shallow dimple that later ponds.
• Modified bitumen loses granules where it is hit, and big stones can fracture the reinforcing mat inside the sheet.
• Metal panels, edge metal, coping and the cabinets of rooftop units dent. Dents in the soft metal are often the easiest evidence that a storm was big enough to matter.
• Skylights, vent caps and condensate lines crack or break.

After a significant storm, photograph the roof and the rooftop units from a safe spot, note the date, and look inside for new stains. Commercial insurance policies are not homeowner policies: some have cosmetic-damage exclusions, separate wind and hail deductibles or reporting time limits, so read your policy and ask your agent. A roofer can document what they see and write a repair estimate; in Colorado only a public adjuster licensed by the Colorado Division of Insurance can negotiate a claim on your behalf. The hail damage and claims page explains the claim side in more detail.

Sun at 5,000 feet

Fort Collins sits at about 5,000 feet, and the UV is noticeably stronger than at sea level. That is hard on any roof surface that faces the sky all day. Older EPDM chalks and shrinks, pulling at its flashings and corners. TPO weathers at the surface, which can make an old sheet harder to weld a patch onto. Modified bitumen without a good granule surface, and any exposed roof cement or sealant, dries and cracks years earlier than it would in a cloudier city.

High-altitude sun also means big daily temperature swings. A dark roof can go from below freezing at dawn to very hot by afternoon in spring and fall, so the membrane, the metal edge and the walls around it move every day. That movement is why sealant joints at coping and counterflashing fail on a short cycle here, and why repairs done with caulk alone rarely last.

Wind at the edges and corners

Strong downslope winds come off the foothills several times a year, mostly in the colder months, and gusts can be very high. On a low-slope roof, wind pulls hardest at the perimeter and the corners, not in the middle of the field. What that looks like:

• Edge metal and coping loosened at the joints, then lifted.
• Membrane peeling back from a parapet or a termination bar that has worked loose.
• A seam near the corner that opens, then lets wind get under the sheet.
• Loose gravel or debris thrown across the roof and into the membrane.
• Rooftop unit panels and vent caps blown off, leaving open holes in the roof.

A small loose corner is a cheap fix. The same corner left through another windy season can let the wind get underneath and tear back a large section of membrane, so it is worth calling in early.

Snow, drains and the March storm

Winter here is drier than people expect, but the wet storms of March and April can put a heavy load on a flat roof and then melt fast. If the drains, scuppers or gutters are blocked with cottonwood fluff, leaves or packed snow, the meltwater has nowhere to go. It ponds against the parapet or around a curb, finds the lowest seam, and comes into the building, often days after the storm when the sun is out. Clearing drains in the fall and checking them after a big snow is one of the cheapest things an owner can do. Ponding that is still there 48 hours after the melt is a drainage problem to raise with a roofer, because it keeps coming back.

Where small-building leaks usually start

Most leaks begin at a detail, not in the open field of the roof:

1. Rooftop unit curbs and the service path to them. Technicians walk the same route every visit, and tools, screws and panels end up on the membrane.
2. Parapet walls and coping. Open joints, failed sealant and brick that wicks water down behind the base flashing.
3. Drains and scuppers. Clogged strainers, cracked clamping rings, scuppers sized too small for a summer downpour.
4. Penetrations. Pipe boots, pitch pans that have shrunk, and conduit lines resting on blocks that wear through the sheet.
5. Seams and laps, especially on aged glued rubber or mod bit with granule loss.
6. Transitions between an older building and a newer addition, or between a pitched front and a flat back roof.

Your roof system and what a repair should look like

TPO: a light-colored single-ply sheet with heat-welded seams. A proper repair is a welded patch or a new section, done on a cleaned surface. If the sheet is old and will not take a weld, that is a sign the roof is near the end.

EPDM: black rubber with glued or taped seams. Repairs use primer and seam tape or a cured patch. Roof cement smeared over rubber does not bond and is not a repair.

Modified bitumen: asphalt-based sheets in one or more layers. Repairs add new plies over cleaned areas, and torch-applied work needs a fire watch and care near wood parapets and occupied spaces.

Built-up roofs: felt and hot asphalt under gravel, still found on some older buildings. Spot repairs are possible, but the gravel hides damage, so tracing leaks takes longer.

Low-slope metal: standing seam or screwed panels. Look for backed-out fasteners, worn washers, open laps and dented or loose trim.

What an owner can check without walking the roof

• Inside: stained or sagging ceiling tiles, water at the top of exterior walls, rust on steel deck or joists in a mechanical room.
• From a neighboring vantage point or a ladder at the hatch: standing water, debris on the roof, lifted edge metal, dents on rooftop units.
• At the downspouts: water should come out during rain; a dry downspout during a storm often means a clogged drain above.
• After every service call: ask the HVAC company whether they saw or caused any damage, and ask for photos.
• Your records: install date, system, warranty documents and every repair with photos and the name of who did it.

If you do go on the roof, use the access hatch, stay away from edges and skylights, and do not go up when there is snow or ice.

A maintenance rhythm for this climate

A spring check in April or May, after the wet snows and before hail season, catches what winter opened and confirms the drains are clear. A fall check in September or October clears leaves and cottonwood debris and tightens anything loose before the windy season. Add a look after any hailstorm, and after any major wind event. A written report with photos each time makes it easier to show when damage happened. The roof inspection page describes what a good written report includes.

Commercial roof repair, start to finish

1. Interior first. The roofer looks at where the water shows inside, because it can travel a long way along the deck before it drips.
2. Trace it on the roof. Check the details uphill of the stain: curbs, drains, flashing and seams. A water test may confirm the source.
3. Test for wet insulation. Ask about core cuts or a moisture survey. Saturated insulation stays wet under a membrane, adds weight and keeps feeding leaks, so patching over it rarely solves the problem.
4. Repair to match the system, and fix the drainage or detail that caused it, not only the hole.
5. Document it. Before and after photos and a written description you can file.

When repair stops making sense

If large areas of insulation are wet, the membrane is cracking across the field, hail has damaged most of the roof, or repairs keep appearing in new places, it is time to price a re-cover or a replacement. A coating may extend a dry, sound membrane, but it is not a fix for wet insulation or failed seams. Whether a new roof can go over the old one depends on the existing layers and on code, so check with the City of Fort Collins (or your town's building department) and ask each bidder how they handle it.

How bids for the same roof can differ

Ask every bidder to put these in writing so you can compare line by line:

• The cause they found, and where.
• The repair method and the materials, by name.
• Whether they tested for wet insulation, what they found, and a unit price for more.
• Drainage corrections included or excluded.
• How they will protect tenants, inventory and the area below.
• Who handles any permit, and whether it is in the price.
• The workmanship warranty on the repair, with its term.

On a bigger project, also compare edge metal and coping, tapered insulation for drainage, and how rooftop units will be disconnected and reset. Commercial roofs are priced per square foot, and the cost page covers houses, so ask for a separate written quote for the building.

Warranty types

• Workmanship warranty from the contractor, covering their labor for a stated term.
• Material warranty from the manufacturer, covering defects in the product.
• System warranty from the manufacturer on a new roof put on by an approved installer, sometimes after the manufacturer inspects it. These often require documented maintenance, so keep the reports.

If the roof is still under warranty, contact the warranty holder before anyone else cuts into it, or you may lose coverage.

Questions to ask a commercial roofer

• What low-slope roofs have you repaired recently, and can I see photos or speak to an owner?
• Which membranes do you work on, and do you do welding, torch work or both?
• How will you check for wet insulation?
• How will you handle the rooftop units and the HVAC contractor?
• Can I see your license and certificate of insurance?

The city does license roofing contractors, so check a roofer's license with the City of Fort Collins (or your town's building department) before work starts. If you lease, read the roof clause in the lease first and ask an attorney if the split between landlord and tenant is unclear.

Getting a written estimate

If water is coming in now, protect electrical equipment and inventory, put down buckets, and photograph everything with the date. Then call or request an estimate. For a building with a pitched shingle section, the roof repair page covers that side, and the Class 4 shingles page is useful if part of the building is steep-slope.