By Ace Roofing & Construction Published Last updated
To prepare your roof for the rainy season, do five things in the fall: clear drains, scuppers and gutters; check skylights; look at flashing around walls, chimneys and vents; look for ponding spots and debris on flat roofs; and book a roof inspection if it has been more than a year or you've had leaks before. Most winter leaks we see in the Bay Area could have been prevented by one of these steps.
Here's the full checklist, what you can safely check yourself, and what's better left to a roofer.
Why fall is the time to do it
Bay Area weather sets up a pattern that's hard on roofs. Months of dry weather and sun dry out sealants and roofing materials. Leaves, dust and debris build up on roofs and in gutters. Then the first big storms arrive — sometimes with heavy rain in a short time — and every clogged drain and tired seal gets tested at once.
Doing your roof prep in early fall, before the first serious rain, gives you time to fix anything you find while the roof is still dry. Permanent repairs on most roofing systems need dry conditions. Once storms start, roofers get busy and repairs get harder to schedule.
The fall roof checklist
1. Drains, scuppers and downspouts
On flat roofs, these are the most important items on the list. Clear leaves, dirt and debris from roof drains and scuppers, and make sure downspouts flow freely to the ground or the sewer connection. A clogged drain can back water up over flashing and into the building. Our flat roof leak guide explains why.
2. Gutters
On pitched roofs, clean gutters and check they slope toward downspouts. Look for sagging sections, loose brackets and leaks at the seams. Overflowing gutters can push water behind fascia boards and into walls.
3. Skylights
Look at the skylight frames from inside for old stains, peeling paint or condensation marks. From the roof, a roofer checks the curb flashing and seals. See skylight leak causes and fixes.
4. Flashing
Flashing seals the roof at walls, chimneys, parapets, vent pipes and other penetrations. Signs of trouble include gaps, rust, lifted edges, cracked pipe boots and dried-out sealant. These are small fixes before winter and much bigger problems after.
5. Ponding areas and debris
On flat roofs, note where water sat after the last rain — look for dirt rings or stains. Remove branches, leaves and anything else sitting on the roof. Trim tree branches that hang over the roof.
6. Shingles and roof surface
From the ground, with binoculars if you have them, look for missing, cracked or curled shingles, bare spots on cap sheets, and blisters or cracks on flat membranes.
7. Inside the house
Check top-floor ceilings, the attic if you have one, and closets under the roof for stains, musty smells or soft spots. Old stains are clues to where the roof has leaked before.
What to check yourself — and what to leave to a roofer
Plenty of this list can be done from the ground, from a window, or from inside the house. Going up on the roof is a different matter. Roofs can be slippery, especially with morning fog, and many San Francisco buildings are tall with steep access.
- Safe for most homeowners: checking ceilings and the attic, looking from the ground or windows, cleaning ground-level gutters with a stable ladder and a helper
- Better left to a roofer: walking any roof, working at height, checking flashing up close, clearing roof drains on multi-story buildings
If you're not comfortable on a ladder, don't go up. A roof check is inexpensive compared to an injury.
When an inspection is due
A good habit is a professional roof inspection once a year, ideally in the fall. Book one sooner if:
- Your roof leaked last winter, even if it seemed to stop
- It's been more than a year since anyone looked at the roof
- You've had work done on the roof by other trades — solar, HVAC, antennas
- Your roof is getting older and you want to plan ahead
- You've just bought the home
An inspection tells you what needs attention now, what can wait, and how much life the roof has left. Our article on what happens during a roof inspection explains what we check. You can book through our roof inspection service.
Extra notes for fog belt and coastal homes
Homes in the Sunset, Richmond, Daly City and other areas near the ocean deal with fog and salt air much of the year. Moss and algae can grow on shaded roof areas, and metal flashing can corrode faster. Pay extra attention to north-facing slopes, shaded flat sections and any exposed metal. Our article on roofing materials for the Sunset's fog belt has more.
A note on solar panels and rooftop equipment
If you have solar panels, HVAC units or other equipment on the roof, ask the roofer to look at the mounts and the flashing around them. Equipment can trap debris and block drainage paths, and penetrations for mounts are another place where water can get in.
After the first big storm
Even with good prep, the first big storm of the season is a test. Afterward, walk through the house and look at ceilings, especially on the top floor, under skylights and around chimneys. Check that downspouts drained and that no water is standing on flat roofs a couple of days later.
If you see anything new — a stain, a drip, a damp smell — deal with it while it's small. A note of what you saw and when, plus a few photos, helps a roofer find the source quickly.
Fix small problems now
The point of fall prep is catching small problems while they're still small. A cracked pipe boot, a loose flashing edge or a clogged drain is a quick repair in October. In January, the same problem can mean a wet ceiling and damaged insulation. We believe in repair before replace — and a lot of the time, a fall tune-up is all a roof needs. Our roof repair service and skylight and drain repair handle these jobs.
If a leak starts anyway, read what to do when your roof leaks during rain.
Frequently Asked Questions
When should I get my roof ready for the rainy season?
Early fall, before the first big storm. That leaves time to schedule any repairs while the roof is still dry, which most permanent repairs need.
How do I check my roof without climbing on it?
Look from the ground or a window with binoculars, check gutters and downspouts at ground level, and inspect ceilings, closets and the attic for stains or musty smells. Leave walking the roof to a professional.
How often should a roof be inspected?
Once a year is a good habit, ideally in the fall, plus after any major storm or if you notice a leak.
What's the most common cause of winter roof leaks?
On flat roofs, clogged drains and scuppers are among the most common. On all roofs, failed flashing at walls, chimneys, vents and skylights is a frequent cause.
Can a roof be repaired in the rain?
Temporary fixes can sometimes be made to slow water during rain. Permanent repairs usually need dry conditions, which is why fall prep matters.
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