Flat Roof Repair Guide
Flat Roof Repair in Clifton, NJ: What to Fix Before Winter
Flat roof repair in Clifton, NJ is easiest to get right in the fall, before freezing weather. Check the seams, the edge where the flat roof meets the house wall, the drains and anything that goes through the membrane. Small openings at those spots tend to grow over a winter of freezing and thawing.
Plenty of Clifton houses have a flat roof you never see from the street: the roof over a back addition, an enclosed porch, a sunroom or a garage. Clifton is a city in Passaic County and, at the 2020 census, the 11th-most-populous municipality in New Jersey, with 90,296 residents. Many of its homes are older, and decades of additions left a lot of low-slope roofing behind them. This guide covers what to look at on that roof in October and November, and what a repair that lasts through winter involves.
Why fall is the time to look
A flat roof holds water until it drains. In summer, a small gap in a seam may only let in a little water during a heavy storm. In winter, water that gets into that gap freezes, expands and pushes the gap wider, then thaws and runs further in. Our flat roof repair page lists freeze-thaw at the seams as one of the common ways flat roofs wear out in North Jersey.
Leaves are the other reason. Fall is when drains and scuppers on low roofs fill up, and a blocked outlet in December can turn into an ice dam on a flat roof, with water backing up against the seams and the wall flashing.
Repairs also go better in mild weather. Most membrane adhesives, primers and sealants list a minimum application temperature on the label, and a seam bonded below it may not hold. A repair done in October has a better chance than one done in an emergency in January.
The five places Clifton flat roofs usually leak
On the flat roofs we get called to, the leak is usually at a joint or an edge, somewhere the membrane had to be cut, lapped or turned up.
- Seams. Where two sheets of EPDM rubber meet, or where modified bitumen rolls overlap, the seam can lift at the edge. On older roofs you can sometimes see a gap you could slide a fingernail into.
- The wall edge, which is the big one on additions. On a back addition, the flat roof runs into the wall of the main house. The membrane turns up the wall and should be covered by flashing tucked behind the siding or set into the brick. When that cover pulls away, water runs down the wall and behind the membrane.
- Anything bolted or piped through the roof: pipe stacks, vent hoods, satellite mounts, the old antenna bracket nobody took down. Each needs its own boot or flashing.
- Drains, scuppers and edge metal. Where water leaves the roof, the membrane is cut and sealed around metal. Clogs make the water sit there longer, and edge metal that has come loose lets wind under the membrane.
- Old patches. Many Clifton flat roofs have been patched more than once, sometimes with a material that does not match the roof. A glued patch on a heat-welded roof is likely to leak again.
What you can check without climbing up
Stay off the roof. Membranes can be slippery, and a soft spot can give under your weight. From a second-floor window that looks over the addition, or from the yard, look for:
- Seams that look lifted, wrinkled or open at the ends
- Leaves or debris piled at the drain or in the scupper box
- Flashing on the wall that has pulled away or is bent out
- Bubbles or blisters in the roof surface
- Dark patches of moss or algae, which usually mark where water sits
Inside, check the ceiling of the room under the flat roof, especially near the wall it shares with the main house. A stain right along that wall usually points to the wall edge, not the middle of the roof.
If you have noticed water staying on the roof for days after rain, read our guide to standing water on flat roofs. Ponding has its own causes and fixes, and it is worth sorting out before the leaves come down.
What a lasting flat roof repair includes
A tube of roof cement over a seam can stop a drip for a few weeks, sometimes longer. Through a Clifton winter, usually not. What we do on a repair that has to last:
- Finding where the water actually enters. On a flat roof the leak is rarely right above the stain, so the roofer walks the membrane and traces the failed seam or flashing.
- Matching the existing material, so EPDM gets EPDM and modified bitumen gets modified bitumen. TPO is welded, not glued. The surface is cleaned and primed first or the new seam will not bond.
- Resetting or replacing wall flashing where the membrane turns up the house, and sealing the top edge so water cannot get behind it.
- Re-flashing pipe stacks and vents with new boots instead of adding more sealant to old ones.
- Drains and scuppers cleared while we are up there.
We repair EPDM rubber, TPO and modified bitumen roofs. On our flat roof repair in Clifton visits we photograph what we find, give you a written, itemized estimate, and back the repair with our 2-year roof repair warranty.
When repair is not enough
A repair makes sense when the membrane is sound and the problem is a seam, a flashing or a penetration. It is harder to justify when:
- Seams are failing in many places, not one or two
- The membrane cracks or tears when it is lifted
- The surface feels soft underfoot, which can mean wet insulation or decking below
- The roof already carries several layers of patches
In those cases the honest answer may be a new membrane over that section, and our roof replacement in Clifton page explains what that involves. If you are not sure which side of the line your roof is on, a roof inspection in Clifton will settle it with photos.
Small things to do before the first freeze
- Clear gutters and the area around scuppers if you can reach them safely from the ground or a stable ladder.
- Have branches that hang over the addition trimmed back, so fewer leaves land on the roof.
- Ask cable, satellite and HVAC technicians to tell you when they have been on the roof, because ladder feet and dropped tools puncture membranes.
- Take a dated photo of the roof after a big rain. A few photos over a season show whether a problem is getting worse.
Book a flat roof check in Clifton
Four Seasons Roofing and Construction is based at 38 Speer Ave in Clifton, so flat roof work anywhere in the city is local for us. The inspection is free, and you get photos and a written estimate before any work starts. See everything we do in the city on our Clifton roofing page, or call (862) 318-3997 to book a look at your flat roof before winter.