Project · Commercial Roof Repair · Hackensack, NJ
Commercial Roof Drain Repair on a Modified Bitumen Roof in Hackensack, NJ
A failed roof drain replaced and re-flashed with torch-applied modified bitumen on a commercial building, completed in February 2026.
- Hackensack, NJ (Bergen County)
- Commercial building, low-slope flat roof
- Roof drain replacement and flat roof repair
- Torch-applied modified bitumen (mod-bit)
- Completed February 2026, winter conditions
- Top Roof LLC, NJ HIC #13VH11535000
The problem
On a flat commercial roof, the drain is where every gallon of water ends up. On this Hackensack building the drain assembly had been patched over more than once, the membrane around it had cracked and pulled away from the drain flange, and water was getting under the roof instead of into the pipe. The tenant was seeing stains inside every time it rained or the snow melted.
The roof itself is a modified bitumen system in fair condition, so a full replacement was not the right answer. The fix was to rebuild the drain area properly: remove the old drain, get down to a sound deck, and tie a new drain into the existing mod-bit roof so the repair is as watertight as the rest of the field.
What we did
- Cut out the failed drain and the built-up layers of old patches around it, back to solid roof and a clean drain opening.
- Checked the deck and the drain bowl for rot and corrosion before rebuilding, and cleared the drain line so it actually carries water off the roof.
- Set the drain flange and clamping ring so the membrane is mechanically clamped, not just glued down.
- Torched in new modified bitumen: a base sheet run over the drain sump, then a cap sheet lapped and sealed into the surrounding roof so there is no open seam at the drain.
- Installed a new strainer dome to keep leaves and debris out of the line and finished the field around the sump.
The result
The drain now sits in a clean, sealed sump with the new membrane lapped well past the old repair area. Water runs to the drain and out, not under the roof. Because we repaired the drain rather than replacing the roof, the building owner solved the leak for a fraction of the cost of a new roof and bought years more service out of the existing modified bitumen system.
Drain and flashing failures are the most common leak we find on commercial flat roofs in Bergen County. If your building has a recurring stain under a drain, a scupper or an HVAC curb, the fix is usually targeted, not a whole new roof. We work on commercial roofing across Hackensack, Englewood and the rest of the county.
Before, during and after
Leak at a drain, scupper or curb on your building?
Book a free on-site inspection. We find the source, photograph it and leave you a written, itemized proposal for the repair, not a sales pitch for a new roof.