Seams, drains and standing water on low roofs
Flat Roof Repair in Verona, NJ
A flat or low-slope roof over a porch, addition or garage sheds water slowly, so a split seam, a clogged drain or a patch of standing water can leave a stain on the ceiling below. Call (862) 396-4866 to ask for a visit.
What changes the size of the job
What decides patch, recoat or rework
The roofing manufacturers' association wants a roof to fall at least a quarter of an inch for every foot, so water leaves freely, and traces ponding to deck deflection, clogged drains and runoff from rooftop equipment. How much of the surface holds water, how old the membrane is and whether low spots can be raised with tapered insulation all change the job. Crickets and saddles, small raised sections upslope of equipment and between drains, are another remedy the association lists for localized ponding.
Stop and step back if
- Under a flat roof, a ceiling that droops or holds a pool of water: leave the room and call 911, since water can be trapped above it.
- Water close to light fixtures or outlets below the roof: keep out of that room, then call 911.
- Standing water or snow on a roof you could reach by ladder: do not step out onto it.
- Do not climb up to clear snow or ice from a flat roof. Watch it from a window.
This job and its partner
A seam on the flat side or metal at the wall
A flat roof meets a wall or chimney somewhere, and the joint there fails differently from a seam in the open field. If the stain sits beside brick or siding, the problem may be the metal and not the membrane. Chimney flashing repair covers that partner job. If the stain sits under a low spot far from any wall, ponding is the likelier cause. The contractor can tell which by looking at both.
What to look at
Why a puddle that stays is a problem
The association lists what lingering water does: it adds load that can deflect the deck, lets ice scrub the membrane through freeze-thaw cycles, feeds algae and vegetation, and carries debris that damages the surface. Heat is the other stress, since Energy Department figures put a conventional roof at 150 degrees Fahrenheit or hotter on a sunny summer afternoon. At the Caldwell airport station, the July normal high is 85.2 degrees; the roof surface can run far hotter than the air. Weight is a second worry, and FEMA's guide to returning to a flood-damaged home warns that water may be trapped in a ceiling.
On a visit, in order
- 1
Call (862) 396-4866, describe where water collects and how the ceiling below looks, and ask to set up the visit.
- 2
The contractor can check for standing water and note where it gathers after a rain; the roofing manufacturers' association calls water that stays 48 hours or longer ponding.
- 3
Seams, laps, the flashing where the roof meets a wall, and any patches or blisters in the membrane come next.
- 4
Drains, scuppers (openings that let water out through an edge wall) and gutters get checked for debris.
- 5
From the room below, the contractor can look at the ceiling and at any dip in the deck under the weight of water.
- 6
Options and paperwork close the visit. The paperwork page covers the permit questions for the four towns.
The parts involved
Membrane, seam, drain and edge
Low-slope means a pitch of 2:12 or less, according to the Energy Department. The surface is usually a single-ply membrane, a built-up roof with a cap sheet, or spray foam. Seams are where sheets join, and they are common leak spots. The drain or scupper moves water off the roof, and the edge detail ties the membrane to the wall or the gutter. A failure in any of the four shows up as the same ceiling stain.
Signs to look for
- Water still pooled on the flat surface two days after the rain
- Blisters, splits or open seams seen from an upstairs window
- A stain on the ceiling of the room under an addition or porch
- A drain, scupper or edge gutter packed with leaves
- Green or dark growth in the spot where water collects
Paperwork pointer
Paperwork on a flat roof job
The state's ordinary maintenance notice speaks of stand-alone one- and two-family houses and is silent on attached dwellings and mixed uses, so a flat roof over an addition or an attached unit may raise a question it does not answer. Verona exempts a shingle swap from permitting but not sheathing repair. The paperwork page lists the four offices to ask.
Have this ready
Write down the address, what is visible from the ground and the roof's age if known, then call (862) 396-4866. Tenants start with the landlord. Towns covered: Verona, Cedar Grove, North Caldwell, West Orange.