Commercial Roof Repair Questions in Richmond

Commercial roof repair fixes a specific failure on a commercial roof while the rest of the roof system stays in service. The goal is to stop water at its entry point and restore the damaged section to match the roof around it.

Typical repair jobs on low-slope and metal roofs:

• Split or open seams on TPO, EPDM and modified bitumen.
• Torn base flashing at parapets, curbs and walls.
• Backed-out screws and cracked washers on metal panels.
• Punctures from foot traffic, hail or dropped tools.
• Clogged or broken drains, scuppers and gutters.
• Loose edge metal and coping after wind.

A few isolated failures call for repair, a worn surface over dry insulation calls for restoration, and widespread wet insulation or rusted-through metal calls for replacement.

Moisture readings and core cuts separate restoration candidates from replacement, since wet insulation underneath a dry-looking membrane rules out a coating.

Temporary repairs buy time by keeping water out of the building, and permanent repairs rebuild the failed spot with materials matched to the roof system.

Every temporary patch on a membrane roof gets cut out or cleaned off when the permanent repair goes in, because roof cement interferes with welds and seam tape.

Edges and penetrations fail first because they are where the membrane or panels change direction, meet another material or move against something fixed. A pipe boot, a curb corner or a parapet base sees daily expansion and contraction that the open field of the roof avoids.

Wind also pulls hardest at the perimeter, lifting edge metal and coping. Sealant at counterflashing and pitch pans dries out in sun faster than the membrane wears. For that reason, a repair visit starts at the perimeter, curbs, drains and every pipe through the roof before moving to the open field.

Each membrane has its own seam repair, because TPO and PVC weld with heat while EPDM and modified bitumen rely on adhesives, tape or heat-fused asphalt.

Seam repairs extend a few inches past the failed section on both ends.

Ponding water is fixed by finding why it sits there, which is usually a clogged drain, a drain set too high, sagging deck or crushed insulation. Clearing debris from drain strainers and scuppers solves the simplest cases.

For low areas that stay wet after the drains are clear, repair options include:

• Adding tapered crickets in the low area and patching new membrane over them.
• Resetting a drain bowl lower so water reaches it.
• Cutting out crushed insulation and replacing it with firm board.
• Installing a scupper through the parapet where water collects at the edge.

Long-term ponding speeds wear on seams and patches, so these repairs protect the rest of the roof too.

Blisters on built-up and modified bitumen roofs are repaired by cutting them open, drying the area, and patching with matching plies once the layers lie flat. They form when trapped moisture or air expands under the surface in summer heat.

Small, firm blisters away from seams and drains often get monitored at each visit. A blister needs repair once it cracks, sits at a lap or keeps growing. Single-ply TPO and EPDM roofs show a different problem, loose areas where adhesive has let go, and those spots get cut, re-adhered and covered with a patch.

Punctures from foot traffic, hail or dropped tools are patched with the same membrane as the roof, set over a cleaned area that extends past the damage. Punctures near RTUs and roof hatches are the most common, since that is where service crews walk and set tools down.

The repair follows a short order:

• Probe the hole and check the insulation underneath for wetness.
• Replace any wet board before closing the roof.
• Clean and prime or prepare the membrane around the hole.
• Weld or adhere a rounded-corner patch.

Walkway pads along service routes cut down on repeat punctures.

Pitch pans are refilled or replaced, pipe boots are swapped for new ones sized to the pipe, and curb flashing is rebuilt where it has split or pulled away. These details leak more than open membrane because sealant and flashing age faster than the field sheet.

Repair choices by detail:

• Pitch pans: old filler shrinks and cracks, so crews refill it with pourable sealer or replace the pan with a premolded boot.
• Pipe boots: cracked rubber and loose clamps get a new boot welded or taped to the membrane.
• Curbs: split corners and open laps at RTU curbs get new flashing run up the curb and under the counterflashing.

Screws on exposed-fastener metal roofs leak when the rubber washer dries and cracks or when panel movement backs the screw out of its hole. Every day the panels heat and expand, then cool and shrink, and that motion works against each fastener.

Repairs for fastener leaks:

• Tighten screws that still bite firmly and have good washers.
• Replace screws with cracked washers using new screws and washers.
• Upsize to a larger-diameter screw where the hole has stripped.
• Seal the heads with fastener caps or sealant on roofs with heavy back-out.

A full fastener pass covers every screw on the roof, since one leaking row tends to mean others are close behind.

Leaking laps are repaired by opening or cleaning the joint, replacing failed sealant and fasteners, and sealing the lap with tape or reinforced sealant. End laps leak more often than side laps because water runs straight into the joint where one panel overlaps the next downslope.

On low-slope R-panel roofs, water also gets pulled into laps by capillary action. Crews check for rust staining at the lap, missing stitch screws and gaps where the panel ends have spread apart.

Rusted metal panels can be patched when the rust is limited to small spots and the surrounding steel is still firm, but panels rusted through in larger areas need replacing. Crews test the steel by pressing on it with a screwdriver.

Rust at the eave is common because water and debris sit there longest. Panel replacement on exposed-fastener roofs means matching the rib profile so laps seal.

Gutters, valleys and ridge caps are repaired by resealing seams, replacing rusted sections and refastening loose pieces. Each one handles a lot of water or wind, so small failures turn into interior leaks quickly.

Common fixes:

• Gutters: reseal end caps and joints, replace rusted sections and reset hangers so the gutter slopes to its downspout.
• Valleys: clear debris, replace rusted valley metal and reseal where panels meet it.
• Ridge caps: replace missing closures, refasten the cap and seal laps between cap sections.

Downspouts get checked at the same time, because a blocked downspout overflows the gutter back toward the wall.

Membrane roof repairs center on seams, patches and flashing adhered to the sheet, while metal roof repairs center on fasteners, laps, trim and replacing damaged steel.

Mixed buildings often have both, with a metal high roof draining onto a membrane low roof, so the joint between them gets its own flashing check.

Roofers trace a leak by starting at the interior stain, measuring its location, and then working uphill on the roof from that point, because water often travels before it drips. On a steel deck, water can run along the flutes for some distance from where it entered.

The tracing order:

• Mark the ceiling stain or drip on a building plan.
• Find the matching spot on the roof and check every seam, curb and pipe uphill of it.
• Look for open laps, split flashing and loose fasteners in that path.
• Water-test suspect spots one at a time, starting downhill.

Water testing pinpoints the entry when visual checks come up empty.

Leaks start in predictable places on each roof type, and checking those spots first speeds up the repair.

Skylights, RTU curbs and parapet walls show up on every list because they break up the roof surface.

Wet insulation can be found from the roof surface with a moisture survey, using infrared, capacitance or similar meters to map areas holding water. Infrared scans work at night after a sunny day, when wet insulation releases heat more slowly than dry.

The survey marks suspect areas on a roof plan. Crews then cut small test cores in those areas to confirm what the meter shows, and patch each core right away.

Building staff should protect people and contents first by moving equipment, setting out buckets and roping off wet floors, and then record where and when the leak appears. Stay off the roof during storms and lightning.

Useful details to record:

• Location of each drip, matched to a column line or room number.
• Time the leak started relative to the rain.
• Wind direction during the storm.
• Photos of ceiling tiles, deck stains and any water running along beams.

Those notes help a crew tie the drip to a specific seam, curb or drain on the roof.

Repeat leaks usually mean the first repair treated the wrong spot or used materials that do not bond to the roof. Water that enters at a curb uphill can show up far from the patch, and roof cement smeared over a TPO seam fails because it cannot bond to the membrane.

Other causes of repeat leaks:

• Wet insulation left under the patch.
• Drains or gutters still clogged, holding water against the repair.
• Movement at expansion joints or long metal panel runs.
• Several leaks at once, with only one found.

A full roof check, rather than another patch on the same spot, breaks the cycle.

Roofs around exhaust fans and process vents are repaired by cleaning off grease or residue, removing membrane the residue has softened, and patching with a material that resists it. Kitchen grease and some process oils swell EPDM and break down other membranes over time.

Repair steps around exhaust:

• Degrease and cut out damaged membrane down to firm sheet.
• Patch with a compatible membrane, often PVC near grease.
• Add a sacrificial pad or grease containment box under the fan.
• Check the fan curb flashing and hinge kit.

Fan filters and grease containment kept in good order mean less residue reaches the membrane.

Roof repairs happen on plant roofs while production runs in nearly every case, since crews work from the outside and open only small areas at a time. Coordination with plant safety staff covers the details that affect operations.

Points to settle with the plant:

• Hot work permits for torch-applied modified bitumen or welding near vents.
• Air intake shutoffs when adhesives or primers are used.
• Lockout of rooftop equipment the crew has to work on.
• Roof access routes, sign-in and fall protection rules.

Repairs over clean rooms, food lines and electrical rooms get extra interior protection.

Expansion joints are repaired by replacing the failed bellows or cover and reflashing both sides, while large curbs get new flashing run up the curb and sealed under the equipment's counterflashing. Both details move more than the roof around them, so rigid patches crack.

Expansion joints on long industrial buildings separate sections that move independently. A split bellows or a joint cover lifted by wind lets water straight into the building. Large curbs under make-up air units and dust collectors leak at corners and along the upper edge where flashing meets the unit.

Equipment changes often leave abandoned curbs, unused pipe supports and open holes where old units sat, and each one needs proper closure. A curb left with a plywood cover or an old pitch pan with no pipe in it is a common leak source on industrial roofs.

Closure options:

• Remove the abandoned curb, infill the deck opening and patch the roof over it.
• Cap a curb that will be reused later with a sealed metal cover.
• Pull unused pipe supports and patch the membrane under them.
• Seal or remove empty pitch pans.

Crews also check new equipment curbs for missing crickets on the uphill side.

Walkway pads along service routes, clear access rules and quick repair of small punctures reduce foot traffic damage on industrial roofs. Service crews walk to RTUs, exhaust fans and roof hatches often, and dropped screws, panels and tools puncture membrane.

Practical steps:

• Install walkway pads from hatches to each piece of equipment.
• Keep a roof access log so damage can be tied to a visit.
• Ask contractors to carry off screws, filters and cut-offs.
• Schedule a roof walk after major equipment work.

Each small puncture found early is a quick patch, while one left open lets water soak the insulation.