Dropped Tools, Loose Screws and Debris
A puncture is often a small, sharp thing under a large, heavy one. A sheet metal screw left on the roof after a cabinet was assembled will not hurt anything until someone steps on it, and then it is pressed through the membrane and into the insulation beneath. The same is true of stone from a neighboring ballasted roof, wire clippings, bits of conduit and the hardware that comes loose from rooftop unit panels.
We sweep the area around every opening we find, because a sharp item that made one hole may have made another nearby. Holes in the sheet are not always where the water appears inside the building, so we mark and photograph each one, follow wet insulation outward, and take moisture readings in a grid. If the roof is large or the leaks are scattered, an infrared moisture survey tells us how far water has traveled beneath the sheet.
Patching Each Membrane the Way It Requires
A good patch begins with a clean, dry surface and a piece of new material that is larger than the damage in every direction. On a thermoplastic membrane, we weld a round or oval patch with a generous lap, because corners become starting points for peeling. On rubber sheeting, the repair is a prepared splice with the right primer and tape. On a modified bitumen or built-up roof, a patch is heated or adhered in layers that match the plies below.
Where the insulation under the hole is wet, we cut it out and replace it first, since a patch over wet board only seals the moisture in. Depending on how widespread the problem is, the repair may be a local fix or a larger section of sheet, and we say which. A patch near a seam is checked for seam failure as well, since the two problems often travel together.
Trades, Tenants and Rooftop Access
Most puncture damage comes from someone who was not working on the roof. An air-conditioning technician, a cable installer, a sign contractor or a solar crew each has a good reason to be up there, and few of them think about the membrane. When an office suite changes use, the roof needs a review before equipment or new openings are added. Arrowhead Pharmaceuticals leased 48,882 square feet in downtown Pasadena, and any tenant fit-out should have its equipment schedule checked against the roof before work starts. The tech companies along the Lincoln Avenue corridor near JPL are another reminder that new tenants arrive with new equipment and a new set of trades on the roof.
A short set of access rules protects the roof. A named contact, a call before anyone goes up, marked walk routes, and a written record of who visited and what they did give the owner something to point to when damage appears. For roofs that carry a lot of equipment, we also review equipment curbs and supports, because clean, well-placed curbs keep service traffic away from the open field.
Walks After the Work Is Done
Punctures are cheap to fix when they are found early and expensive when water has had a season to work. We look at the service paths on every maintenance visit, check each pad, and walk the area around equipment after any contractor has been on the roof. The routine is part of our preventive maintenance, and it lets us spot wear long before the sheet is cut through.
Roofs that will carry solar panels or new equipment deserve the same attention before the work begins. A membrane that is already thin along a walking route will be damaged further when installers carry racks across it, which is why a solar-ready roof is one that has been inspected, repaired and padded first. Past that point, a sheet that has simply aged out is a question of heat and UV damage and how much service life remains.
The same walk-path discipline applies to buildings near Old Pasadena and the South Lake Avenue district. Those areas differ in their setting, but the repair decision still starts with the roof surface, the route to equipment, and the people who need to use the building below.
Commercial Roofing Questions
How do we know whether a contractor's visit damaged the roof?
Compare the roof before and after. Photographs taken before the visit, a record of who was on the roof and a walk afterward by someone who knows the membrane will show new scuffs, cuts and dropped hardware. We check the route to the equipment and the area around each opening, which is where most visit damage turns up.
Do walk pads really protect the membrane?
They do when they match the membrane, are bonded or welded in place, and extend to where the work is done. Loose pads shift, curl and trap water, and short routes leave bare sheet at the end of the path. We install and repair pads along the actual service routes, not just near the hatch.
A small puncture was found, but nothing leaks yet. Can it wait?
Only briefly. A hole that reaches the insulation lets water spread sideways beneath the sheet, and the wet area grows with each rain even if no stain shows. A prompt patch is simple, while wet board and a damaged deck mean a much larger repair, so we recommend closing every opening we find.
Is repairing a coated roof different from patching a sheet membrane?
It is. A coating has to be cleaned, primed and rebuilt over the damaged area, often with reinforcing fabric, and it will not bridge a cut by itself. We look at what is beneath the coating first, because a puncture through a coated roof may have wet the insulation or the old membrane below.
What should our rooftop access rules say?
Name a single contact, require a call before anyone goes up, mark the approved routes and keep a log of visits. Add a requirement that trades remove their debris and report any damage right away. The rules are short, and they keep both the roof and the warranty paperwork in order.
