Find every puncture, not only the one that leaks. A report of a drip points to one hole, but the trade that made it usually left others, and a wet ceiling is the only one that announced itself. The first-hour check is to protect the interior, confirm safe access to the roof, and walk the route the service crew took, because damage follows foot traffic and tool drops along that route.
Puncture damage is not tied to age. A new roof can be cut by a dropped hand tool in its first month, and an old one can be cut the same way. What age changes is the membrane's resistance and the cost exposure behind it. Lowell's NOAA normals total 48.51 inches of precipitation a year, so a hole in the sheet meets rain in any month, and the inspection note records each puncture by location, size and cause.
Weather shapes the response. A puncture found in January is covered with a cold-applied temporary patch, since adhesives and welds need dry, workable conditions, and the permanent patch goes on in the return window. Lowell's January daily mean of 24.9 degrees Fahrenheit makes that wait normal, and the temporary patch is dated and photographed so it can be checked after the next thaw.
Where Punctures Come From
Most punctures come from work done on the roof by someone other than the roofer. HVAC technicians drag tools across the surface, kneel on sharp fasteners and drop panels. Window cleaners, antenna installers, solar crews and signage contractors all need access, and each one can leave a cut, a gouge or a crushed edge. Hail, falling branches and windblown debris add to the list.
We trace damage back to its likely cause by looking at the pattern. Linear scuffs between a hatch and a rooftop unit mean regular service traffic. Round holes near a unit suggest dropped screws or hardware. Clusters of small tears mean impact from falling objects. The pattern tells us where to install walk pads and whether a sign-in sheet at the roof hatch would help. Servicing routes to rooftop equipment are where most of that wear collects.
Equipment installation is a common source. When a new unit, conduit or antenna goes onto a roof, the trade that sets it often drills, cuts and drags material across the membrane. A before-and-after photo set from the roofer, taken at the start and end of that work, settles later questions. We recommend that owners require it in contracts with other trades.
Locating Damage Beyond the Visible Hole
A visible puncture is the end of the search only if the insulation below is dry. Water that enters a hole spreads along the insulation joints and the deck flutes, so the stain and the hole may be far apart. An infrared moisture survey run on a clear evening shows the wet area as a warm patch, and a core sample confirms it.
The survey also finds punctures that nobody has reported. We mark them with paint, photograph each from a fixed height and measure its size, so the repair can be priced as a list. A roof with a few small cuts takes patches. A roof with dozens of cuts on a service route may need a protective layer added, as in a cover board or a walk-pad system.
Patch Methods and Repair Boundary
Patch material has to match the roof system. On TPO and PVC, a heat-welded patch with rounded corners seals the cut and carries the load around it. On EPDM, a cured or uncured patch bonded with the right adhesive does the same. Modified bitumen takes a patch of cap sheet, torched or cold-applied. A rounded corner matters, since a square corner concentrates stress and peels first.
The repair boundary is the area of insulation and membrane that must be replaced if moisture is found. A dry roof takes a surface patch. A wet area is cut out, the board is replaced, and the patch covers the new section. The scope states which applies and what each costs, with a note on the weather hold the work carries. A hole beneath a pond is handled with the cause in the ponding water repair.
Edges of a patch are the weak points. A patch that has been rolled but not probed may have a channel open at one corner. We probe every patch edge after it cools, mark the check on the plan and photograph the result. Patches over seams or flashing are treated as larger repairs, with a cover strip across the full joint instead of a small circle.
Walk Pads and Traffic Control
A patch repairs one injury and does nothing to prevent the next. Walk pads along the route to each unit spread the load and shield the membrane. A designated path from the hatch to the equipment tells every trade where to walk. A sign at the roof access with a short rule about tools and fasteners helps.
We install walk pads in a pattern that follows the actual routes, with gaps for drainage so water does not pond behind them. Pads over seams and flashing get extra care. After installation, a photograph set records the layout. The same preventive maintenance visit that checks drains can check the pads, since sand and debris can wear them out.
Skylights and hatches are special cases. A cracked skylight dome or a hatch that does not close adds a path for water that looks like a membrane leak. We check each one when we walk a puncture report, and a skylight flashing repair goes into the scope when needed.
Cost Update and Records
Puncture repair is priced by the number of patches, the area of any wet insulation, the access and the weather. A few small patches are a short visit. A wet section adds removal and replacement of board. Where the cause is repeated service traffic, walk pads add a line item. The cost update separates these items so the owner can approve each one.
For landlords, the record has another use. Dated photographs of the roof before and after a tenant's contractor visits show who caused a puncture, and the lease can then assign the cost. Buildings in Lowell reached by Route 3, I-495 or I-93 are scheduled in the same way, and a flashing check usually follows a puncture repair near a curb.
Commercial Roofing Questions
How can one trade's damage be separated from another's?
Dated photographs from before each trade's visit. Without them, the pattern of damage and the route to the equipment give a likely cause, but not proof.
Is a patch enough for a hole in an old membrane?
If the surrounding sheet is flexible and clean, yes. If the sheet has hardened or shrunk, the patch has no sound edge to bond to and the cut-out grows until it finds good material.
Do walk pads replace the need for repairs?
No. They reduce new damage on the routes they cover. Existing punctures still need patches, and a roof with many of them may need a protective layer as well.
What if the hole is over an occupied floor?
The interior gets protected first, and the patch goes on the same day when the surface allows it. A moisture survey follows to check how far the water traveled.
Which punctures need immediate attention?
Any that is open to water and sits over a protected space. Cuts in a dry area that is not exposed to ponding can be scheduled for the next repair visit.
