Best suited to
buildings where the field of the roof still has service life and the failure is local.
Flat Roof Repair, at a glance
Most flat roof leaks in St. Louis trace to four places: a failed seam, a curb or pipe penetration, base flashing at a wall, or a drain that stopped draining. John Beal Roofing finds the actual source instead of smearing mastic where the ceiling stain is, and repairs it same day when the weather allows. Call (314) 429-6000 any hour.
The Short Version
Whether This System Fits Your Building
Service life
A correct repair holds until the surrounding membrane ages out.
What to watch
Ponding. water standing more than 48 hours after rain means the drainage is the real problem.
Finding the actual leak on a low-slope roof
On a flat roof the water almost never enters where it appears inside, and the diagnosis is the part genuinely worth paying for.
Water landing on a low-slope roof does not run off. It travels laterally between the membrane and the insulation, sometimes a considerable distance, until it finds a fastener penetration or a deck joint to drop through. The ceiling stain marks where it exited the assembly, which tells you almost nothing about where it got in.
So we survey rather than guess. Seams get probed, penetrations and curbs are inspected individually, and drains and scuppers are checked for blockage. Where the entry point is not obvious, an infrared survey after sundown shows wet insulation as retained heat, and core cuts confirm it. Cutting a small hole to learn what is underneath costs far less than replacing the wrong section.
Patch compatibility is not optional and it is routinely gotten wrong. TPO patches to TPO with a hot-air weld. EPDM needs rubber with the correct primer and tape. PVC needs PVC. Asphalt-based roofs need asphalt-based materials. A tube of generic sealant smeared across a single-ply seam is not a repair, it is a delay, and it often contaminates the surface so the real repair costs more later.
Wet insulation does not dry in place under a membrane. Where the survey finds saturated areas, that section is cut out and replaced with dry insulation before the membrane goes back. Patching over wet insulation is why a repaired roof leaks again in a different spot the following season.
Ponding is a repair item in its own right. Where water stands for days because a drain sits high or the deck has deflected, no patch program holds long term. Sometimes the answer is a new drain or a sump, sometimes tapered insulation in that bay.
We document each repair with photographs and location, which matters on a roof maintained under warranty or tracked against a capital plan.
Installation
Where These Roofs Actually Fail
Membrane failures are almost never in the middle of the sheet. It starts at the curb flashing, the pipe boot, the wall termination and the drain.
So we put the hours into the details nobody photographs. Seams go fast. Curbs, rebuilt properly, take an afternoon, and they are what gets a roof to year twenty.
We register the manufacturer warranty to your building, so the coverage is on file under your address, not lost in a folder.
Related: Ponding water: causes and fixes
Common Questions
How long will this roof last in St. Louis?
A correct repair on a sound roof lasts as long as the surrounding membrane does. A repair on a roof with wet insulation underneath will fail again nearby, which is why we survey before quoting.
Can we recover over the existing roof instead of tearing off?
Recover is a replacement-scale decision rather than a repair, and we will raise it when a survey shows the failures are systemic rather than local. For a handful of defects on a sound roof, a repair is the right spend.
Do you install this system yourselves?
Yes. Diagnosis is the valuable part of a repair, and it is not something we subcontract. The crew locating the leak is the crew that answers for the fix.
What does a repair on this system cost versus replacement?
Repair is dramatically cheaper and is the right answer on a roof with isolated defects and dry insulation. Once a moisture scan shows saturation across a meaningful share of the roof, repairs stop being economical.
How disruptive is the installation?
A repair is typically a single day on the roof with no impact inside the building. Where the diagnosis calls for core cuts, those are patched the same day they are opened.
Free Roof Evaluation
Tell us about the building and a dispatcher will call to schedule.
Related: parapet wall flashing repair in St. Louis — if the stain follows an exterior wall, start at the top of the parapet.