Before winter, a flat roof needs three things: clear drains, scuppers and gutters so water can leave the roof; a close look at the seams and flashing, where most leaks start; and a check of the top-floor ceilings for stains you may have missed. October is a good time to do it, after the heaviest leaf fall starts and well before the first freezes. If you find anything beyond loose debris, a roofer should look at it before the snow comes, because small openings tend to get bigger once water starts freezing and thawing inside them.
The National Roofing Contractors Association recommends roof inspections twice a year, in spring and fall. Below is what a fall check looks like on a typical Philadelphia rowhome or twin, what you can safely do yourself, and when it's time to bring in a pro.
This is general information. For permits and code questions, the City's Department of Licenses and Inspections (L&I), or your township or borough in the suburbs, has the final word.
Why flat roofs need more attention
Most Philadelphia rowhomes and many twins have a low-slope roof, usually called a flat roof even though it should be pitched slightly toward a drain, a scupper or a gutter at the back. Rain doesn't run off a low-slope roof as fast as it does off a pitched shingle roof, so anything that slows drainage, like leaves, a clogged drain or a sag in the deck, leaves water sitting on the membrane.
The building codes have a name for a roof that drains properly: positive roof drainage, meaning the roof dries within 48 hours after precipitation. Water still standing two days after a rain is a sign of a drainage problem, not just a puddle.
Rowhome roofs add a few complications of their own:
- Shared edges. Your roof meets your neighbors' roofs at the party walls. Flashing along those walls, and water coming over from a neighbor's roof, are common sources of trouble.
- Many openings. Roof hatches, skylights, plumbing vent pipes, old chimneys and HVAC equipment all need sealed flashing. Every opening is a place where water can get in.
- Parapets and coping. Low walls at the front or rear of the roof have caps and flashing that crack and separate over time.
Know what kind of roof you have
You'll describe problems better, and understand a roofer's estimate better, if you know the surface. Common low-slope roofs include:
- Modified bitumen: rolls of asphalt-based membrane, often with a granule surface, sometimes coated silver or white.
- EPDM ("rubber roof"): a black rubber sheet with glued or taped seams.
- TPO or PVC: usually white or light gray plastic membranes with heat-welded seams.
- Built-up roofing: layers of felt and tar or asphalt, often covered with gravel or a coating.
If you don't know, take a few clear photos of the surface and a seam. A roofer can identify it from that.
Stay safe first
Many rowhome roofs are reached through a ceiling hatch on a ladder, and few have railings at the edges. Don't go up when the roof is wet, icy or windy, don't step near the front or rear edge, and don't walk on anything that feels soft or spongy, which can mean a wet or rotten deck underneath. Avoid stepping on skylights. If you aren't comfortable climbing up, much of this check can be done from inside the house, from a rear window, or by asking a roofer to do it for you.
Your fall flat roof checklist
- Clear the drains, scuppers and gutters. Remove leaves, twigs, gravel and anything else that has collected at the outlets. Make sure the strainer or cover on an interior drain is in place. Check that the downspout is attached and that water can flow through it.
- Look for ponding. The day after a rain, look for standing water and note where it sits. Dried rings of dirt on the surface show where water has been sitting in the past.
- Walk the seams. Look for edges of the membrane that are lifting, open, wrinkled or blistered. A blister is a raised bubble; don't cut or press it, just photograph it and point it out to the roofer.
- Check the flashing. Look where the roof meets the party walls, parapets, chimney, hatch and skylight curbs, and the vent pipes. Look for gaps, cracked sealant, loose metal and separated membrane.
- Look at coatings. If the roof has a silver or white coating, note bare spots, flaking or cracking. Worn coatings are worth mentioning to a roofer, even though they don't always mean a leak.
- Look at the parapet caps. Loose or cracked coping and open mortar joints let water into the wall below.
- Check from inside. Look at the top-floor ceilings, the top of the stairwell, around the hatch and skylights, and the tops of the walls along the party walls. Brown rings, bubbling paint and peeling plaster are signs of water. Take photos with the date so you can tell if a stain is growing.
- Talk to your neighbors. If their drain backs up onto your roof or their flashing is failing at the shared wall, your house can suffer for it. A quick conversation now beats an argument after a leak.
Leaks: what to do before the roofer arrives
If water is already coming in, put a bucket under the drip and move furniture and electronics away. A ceiling that bulges with water can come down, so keep people out from under it. If water is near light fixtures or outlets, turn off that circuit at the panel if you can do it safely. Take photos of the ceiling and, if it's safe, of the roof above the leak. Roofers will want to know when it leaks: during every rain, only in heavy storms, or only when wind blows from one direction. That helps them find the source, which is not always directly above the stain.
Repair, recover or replace?
You'll hear three kinds of proposals from roofers:
What drives the price is mostly the size of the roof, how many layers have to come off, how much of the deck is damaged, how many openings need new flashing, the material, and how hard it is to get materials up to and debris down from the roof. When estimates differ a lot, ask each roofer to explain what they found and what exactly they are proposing, with photos. Get it in writing.
Permits in Philadelphia and the suburbs
In Philadelphia, roof covering replacement needs a building permit, but it qualifies for an EZ permit without plans, and a roof covering permit can be issued right away when the contractor applying has a current license, insurance and tax account. According to the same page, the work must be done by a licensed Philadelphia contractor, except that in an existing one- or two-family house it can also be done by the owner-occupant or by a registered Pennsylvania home improvement contractor holding a Philadelphia Commercial Activity License.
L&I says you often don't need a permit for repairs related to regular maintenance, as long as your property is not on the Philadelphia Register of Historic Places. If your house is in a historic district or individually listed, check with the Philadelphia Historical Commission before any roof work.
In Bucks, Montgomery and Delaware counties and in South Jersey, the rules come from your township or borough, so ask the code office before work starts. Anywhere in Pennsylvania, check that the roofer is registered with the Attorney General using the home improvement contractor search. Our guide on how to check a contractor in Philadelphia covers the rest of the checks, from insurance to the written contract.
Help for emergency repairs
If a roof leak has already caused serious damage and money is tight, Philadelphia's Basic Systems Repair Program provides free emergency repairs to eligible owner-occupied homes. For roofs, it covers leaks that have caused a ceiling section of 4 square feet or larger to collapse; small leaks don't qualify. You must own and live in the single-family house, not own other residential property in Philadelphia, be current on property taxes and the water bill, and meet the income limits. Call PHDC at 215-448-2160 or check the program page for the current rules.
When to call a pro
Call a roofer if you find:
- water standing more than two days after a rain;
- open seams, lifting membrane, blisters or soft spots;
- cracked or separated flashing at a party wall, chimney, hatch, skylight or vent;
- any new or growing ceiling stain, or a leak you can't trace;
- a roof you can't reach or inspect safely.
When you contact roofers, give them what they need to quote accurately: the roof type if you know it, how many stories the house has and how the roof is reached (hatch, ladder, a neighbor's deck), where the stain or leak is inside, when it leaks, the approximate age of the roof and any past repairs, and your photos.
On HomeKept, you can post your roofing project with those details once and get responses from local roofers. It's free for homeowners, you can compare up to three estimates, and HomeKept covers Philadelphia, Bucks and Montgomery counties. A person reviews every pro profile, and license and insurance badges appear only after documents are checked. That isn't a background check, so still do your own checks before you hire.
HomeKept needs JavaScript. Please enable it and reload the page. ·
HomeKept necesita JavaScript. Actívalo y vuelve a cargar la página. ·
Для работы HomeKept нужен JavaScript. Включите его и обновите страницу.