Flat Roofs in Elizabeth
Walk down a block in Elizabethport, Peterstown or Bayway and look up. Many of the houses end in a short wall instead of a sloped roof. Behind that wall is a roof that's nearly level, built with just enough tilt to send rain toward a drain or an opening in the wall. These roofs cover a lot of two- and three-family houses, attached rows and the buildings with shops downstairs and apartments above. They work well when water keeps moving. Nearly every flat roof leak around here starts with water that has stopped moving, or with a joint that has opened up: a seam, a drain fitting, or the place where the roof turns up the wall.
What Flat Roofs Are Made Of
| Material | What it is | Seams | Where you'll see it |
|---|---|---|---|
| EPDM | A black rubber sheet | Glued or taped | Many reroofed houses and rows |
| TPO | A white or gray plastic sheet | Heat-welded | Newer roofs, storefronts, buildings where a cooler top floor matters |
| Modified bitumen | Asphalt sheets with a granule surface, rolled out in layers | Torched or self-adhered laps | Common on older city roofs and on porch and addition roofs |
| Built-up asphalt and gravel | Layers of felt and hot asphalt topped with gravel | No separate seams | Older roofs; usually removed at replacement |
| Coating | A liquid layer rolled over an existing roof | None | Used to extend a sound roof, not to fix a failed one |
None of these is right for every building. A roofer weighs the building's drainage, how much foot traffic the roof gets, and what's under the current surface.
Parapets and Shared Walls Between Rows
The short walls around a flat roof do two jobs: they hide the roof from the street and they separate one building from the next. Both make them a weak point. The roof membrane has to turn up the inside of the wall and get covered at the top, usually by a metal cap. When that cap loosens or the joint behind it cracks, water runs down inside the wall and shows up on the top floor, often in a corner. On attached rows, the wall between two buildings belongs, in part, to both owners. A roofer can tell you whether the leak is on your side, but repairs that touch the shared wall go better when both neighbors know about them.
Drains, Scuppers and Standing Water
Water on a flat roof leaves one of three ways: through a drain in the middle of the roof that runs down inside the building, through a scupper, which is an opening in the parapet wall, or over the edge into a gutter. Any of them can clog with leaves, roofing grit and the odd tennis ball. Water that sits for more than a couple of days after rain ages the roof faster and finds every small opening. Fixes range from simply clearing the drain to adding tapered insulation under the next roof so water runs where it should. More: ponding, drains and scuppers.
Snow and Ice on a Flat Roof
Snow that slides off a pitched roof stays put on a flat one. It melts from the bottom, the meltwater runs toward a drain that may already be frozen, and the water backs up against seams. A heavy, wet snowfall followed by rain adds a lot of weight. If you hear creaking, see a ceiling bow, or notice doors on the top floor sticking after a big snow, call a roofer before trying anything yourself. Never send anyone up to shovel a roof without knowing it can be done safely.
What Is a Flat Roof Made Of?
Usually one of three sheet materials over a layer of insulation board: black EPDM rubber, white or gray TPO plastic, or modified bitumen, which is a reinforced asphalt sheet. Older roofs may still have built-up layers of felt and asphalt with gravel on top. The roofer can identify yours from a small look at an edge or a seam.
How Do I Know if My Flat Roof Needs Replacing?
Look for leaks in several places, a surface that's cracked or blistered all over, seams lifting in many spots, or a roof that stays wet in more than one area for days after rain. If the insulation underneath is soaked in large sections, patching won't hold for long. A roofer can test for wet insulation and tell you how much of the roof is affected. More: roof replacement.
Working on a Flat Roof Over Tenants
Most flat roofs in the city are reached through a hatch inside the top-floor apartment or a stairway. Give tenants notice, agree on a time, and ask the roofer to protect the floor under the hatch. For a full replacement, the roof should be closed up and watertight at the end of every workday. More: reroofing an occupied two-family.
Flat Roof Work Around Elizabeth
In the city
- ElmoraElizabeth
- Elmora HillsElizabeth
- MidtownElizabeth
- North EndElizabeth
- Frog HollowElizabeth
- PeterstownElizabeth
- BaywayElizabeth
- ElizabethportElizabeth
- WestminsterElizabeth
- Keighry HeadElizabeth
West and north
South and southwest