Finding and Fixing Commercial Roof Leaks in San Bernardino
The scope documents leak sources, repair boundaries, photos, and priorities so San Bernardino owners can separate immediate stabilization from longer-term capital work. A drip hitting the floor of a Fontana fulfillment center rarely starts above the wet spot. Water travels along the deck flutes, down purlins, and across vapor barriers before it shows itself, sometimes a hundred feet from the actual breach. Leak repair is a tracing job first and a patching job second, and we treat it that way on every call.
Why the Wet Spot Lies to You
On a metal deck, water entering at a failed seam runs downhill inside the flutes until it finds a side lap or a penetration, then drops. On concrete decks it spreads laterally under the membrane and surfaces at cracks or conduit sleeves. The stain on the ceiling tile tells you where water exits the assembly, not where it enters the roof.
Patching the membrane directly above the stain is the most common mistake we get called to redo. The building gets a patch, the leak keeps leaking, and by the third rain everyone has lost confidence in roofers generally. Tracing takes more time on the first visit and saves every visit after that.
Interior clues still matter. We start below: where the water shows, how fast it responds to rain, whether it appears only in wind-driven storms. A leak that shows up only during a Santa Ana event with rain behind it points at wall flashings and edge metal, not the field.
How We Trace a Leak on a Big Single-Ply Field
Up top, we work outward from the suspect zone. On TPO and PVC we probe every seam within range with a blunt tool, checking for cold welds that look fine and hold nothing. On older EPDM we check the lap adhesive and every patch someone else installed. On built-up and modified roofs we look for splits at the base flashing, blisters that have broken, and counterflashing that has pulled out of the reglet.
Penetrations get special attention because they cause a disproportionate share of leaks. Pipe boots split in this sun. Pitch pans dry out and crack. Condensate lines from rooftop package units drip onto the membrane year-round and cook a hole in it. Satellite mounts and conduit added by tenants without curbs are reliable suspects on multi-tenant buildings.
When visual and probe work does not close the case, we escalate: flood testing an isolated section, or an infrared scan after sundown to map wet insulation. Wet insulation marks the entry area even when the hole itself is a pinhole. On occupied cold storage in Colton we also rule out condensation first, because a freezer roof can drip from vapor drive with no breach at all.
Repairs That Match the Membrane
Every membrane has a right repair and a wrong one. Heat-welded patches on TPO and PVC, with the surface cleaned and primed so the weld actually fuses. Cured cover tape or new lap splices on EPDM. Torch or cold-applied patches on modified bitumen, sized past the damage, never dabs of mastic. Mastic smeared over a split is a ninety-day repair, and the Inland Empire sun makes it a sixty-day repair.
The materials on the truck for a typical leak call include:
- Membrane patching stock matched to TPO, PVC, EPDM, and modified bitumen
- Seam probes, weld testers, and a hot-air welder for single-ply work
- Pipe boots, pre-molded corners, and pitch-pan filler for penetration failures
- Fasteners and plates for re-securing loose membrane and edge metal
- Drain strainers and clamping-ring gaskets, since drains cause plenty of calls
If the leak traces back to a clogged or failed drain assembly rather than the membrane, that repair path is covered in detail on our roof drains and scuppers page.
Rain Comes Rarely Here, and That Is the Trap
San Bernardino can go six or eight months without meaningful rain. Small breaches sit harmless all summer while UV keeps working on the membrane, then the first real Pacific storm in November finds every one of them the same week. Our leak calls spike with the first storm of the season, and buildings that got a summer inspection are almost never on that list.
Summer is not entirely safe either. Monsoon moisture pushes over the San Bernardino Mountains in July and August and drops short, hard bursts on the east valley: Highland, Redlands, Mentone. Those cells dump water faster than a marginal drain field can shed it, and ponding finds seams that ordinary rain never tests.
The practical takeaway for owners: get suspect roofs looked at in September and October, before the storm track arrives. A seam repair in dry weather is a small line item. The same seam found during an atmospheric-river week, with product staged under it, is a claim.
What You Get After the Repair
Every leak repair we close out comes with documentation: photos of the breach as found, photos of the completed repair, a roof plan marking the location, and a note on the likely cause. Portfolio managers running buildings from out of state rely on that record, and it keeps the history straight when the building sells or the roof warranty gets exercised.
We also tell you what we saw around the repair. One failed seam on a fifteen-year-old roof is usually not alone, and a repair visit is a cheap chance at an honest condition read. When the membrane is near the end, we say so and lay out the options, but we do not turn every service call into a replacement pitch. Most leaks are worth fixing on their own terms.
Leak Repair Questions, Answered Plainly
Can you find a leak when it is not raining?
Usually, yes. Seam probing, flashing inspection, and infrared moisture scanning find most breaches in dry weather. When a leak is stubborn, we flood-test isolated sections with controlled water to reproduce it. Dry-season tracing is actually easier, because the insulation moisture pattern around the entry point is still mapped from the last rain.
Why does my roof only leak during wind-driven rain?
Because the breach is vertical, not horizontal. Wall flashings, coping joints, and edge metal shed ordinary rainfall but let in water that arrives sideways. Santa Ana-driven storms push rain up under terminations that gravity never tests. Those repairs happen at the perimeter and parapets, not out in the field.
Is one leak a sign the whole roof is failing?
Not by itself. A puncture from a dropped tool or a split pipe boot is an isolated event on an otherwise sound roof. What changes the answer is pattern: multiple seam failures, widespread wet insulation on a scan, or repairs clustering closer together each season. We give you the read either way, with photos.
How fast can you respond when water is coming in?
Active-leak calls get priority dispatch, and for buildings on our maintenance program we hold committed response times. If permanent repair cannot happen same-day because of weather or material, we stop the water with temporary measures and schedule the permanent fix immediately behind it.
Will the repair be covered under my roof warranty?
If your membrane is under a manufacturer warranty, repairs generally must be performed by an authorized contractor to keep it intact, and some causes fall under the warranty itself. Bring us the warranty terms and we will work within them and route covered items to the manufacturer correctly.