Flat Roof Maintenance: The Fall and Spring Checklist for Chicago Owners

Drains, scuppers and downspouts

This is the most important group. Clogged drains are the fastest way to turn a small roof into a pond.

• Roof drains are clear of leaves, seeds, gravel, and debris
• Drain strainers or domes are in place and not cracked or missing
• Scuppers (the openings through a parapet wall) are open and not blocked by debris or roofing material
• Gutters and downspouts are attached, not rusted through, and not leaking at joints
• Downspouts discharge away from the building, not against the foundation or brick. Extensions or splash blocks should push water about 4 feet away from the wall
• You know where the overflow drain or overflow scupper is, if the building has one. Secondary drains may be required by local plumbing code
• After a hard rain, the roof sheds its water. If water is still sitting 48 hours later, treat it as ponding

Ponding water and low spots

• Standing water is gone within 48 hours of a rain. Water that stays longer is defined as ponding, and it can overload the deck, grow algae, clog drains and wear out the membrane faster
• No algae, moss, or green or dark stains marking where water sits
• No visible sag or soft spots in the roof surface
• No low area between drains or beside rooftop equipment (a saddle or cricket is the usual fix)
• Interior ceilings below the low spots show no brown stains or bubbling paint

Membrane surface and seams

The roofing industry (NRCA) groups flat roofs into built-up, modified bitumen, EPDM rubber, TPO and PVC, and other types. The checks are similar.

• No blisters, bubbles or raised areas that sound hollow or feel soft
• No cracks, splits, alligator pattern or surface crazing
• No exposed fabric, bare patches or worn spots where the surface is missing
• Seams are tight, flat and sealed, with no lifted edges or open laps
• No tears, punctures or foot traffic damage, especially around hatches, equipment and a rooftop deck
• Patches from earlier repairs are still sealed and have not peeled
• Loose gravel, if your roof has it, is not piled up or cleared away from drains

Flashing, parapets and edges

This is where leaks start most often, because water gets behind the wall and the membrane is cut or turned up there.

• Membrane turned up the parapet wall is attached, with no gaps or lifted edges
• Flashing at tops of walls, parapets, chimneys and roof penetrations is intact, tight to the surface and not cracked, rusted or pulled loose
• Sealant at pipes, vents, hatches and curbs is soft but not cracked or missing
• Parapet coping or cap is in place, with no missing pieces, wide gaps or open joints. Its job is to channel water away from the wall
• Brick on the parapet shows no loose or missing mortar and no loose bricks
• Chimney has no loose brick, open joints or cracked crown
• Rooftop vents, hatches and skylights are sealed all around

Inside the building

• No brown or yellow ceiling stains, especially top-floor ceilings and walls near the parapet
• No peeling paint, bubbling plaster, damp insulation or musty smell in the top unit
• No daylight visible in the attic or at roof penetrations
• No water marks on a wall that runs along the parapet

What to do with what you find

Do it yourself, if you can do it safely: clear leaves and debris off drains, scuppers and gutters, tidy loose gravel, and clean strainers. This is basic housekeeping, and it is the most useful 20 minutes you can spend on a flat roof.

Call a roofer soon if you find: ponding that lasts past 48 hours, blisters or splits, lifted seams, loose flashing, open parapet joints, a cracked coping, or any interior stain. A small repair now is easier than a wet ceiling later. Photograph everything first.

Call right away if you find: water coming in, a soft or sagging spot in the deck, a parapet or chimney that is loose, or a roof that appears to be pulling away from the wall. Keep people out of the area below and do not walk on the roof.

A few rules to know before hiring. In Illinois it is unlawful to provide professional roofing services without a roofing contractor license. There is an exception for a person doing roofing work on their own property. In Chicago, the City's no-permit list says roof repair on pitched roofs is exempt but that a permit is required for any work on low-slope roofs. A separate City line exempts patching limited to 25 percent of the roof area if no part of the roof or wall is cut away. These two statements can read differently for a flat roof, so ask the Department of Buildings before any repair beyond cleaning. For a reroof, the Express Permit rules require a licensed roofing contractor and do not allow Express for a building with an unpermitted rooftop feature such as a roof deck.

For the causes behind these problems, see flat roof drainage in Chicago, ponding water on a flat roof and why flat roofs leak. If you are thinking about timing for a bigger job, read the best month to replace a roof in Chicago. The rest of the picture is in our Chicago roofing guide. When you would rather have a pro look at it, our roofing crew can walk the roof and tell you what is a patch and what is a plan.