Roof Maintenance Before Winter: DIY Checklist

The best time to find a roof leak is on a dry afternoon in the fall, not at midnight during the first big storm. A little roof maintenance before winter can stop small problems from turning into ceiling stains, rotted wood and emergency calls. This checklist covers what a California homeowner can safely do, what to look for, and when to stop and call a licensed roofer.

This year it matters more than usual. NOAA's Climate Prediction Center has an El Niño Advisory in place for the 2026 to 2027 winter, and a strong El Niño tilts the odds toward a wetter season in much of California. Our guide to El Niño and your roof explains the forecast.

Think of roof maintenance before winter as a once a year habit, like changing smoke alarm batteries.

When should you winterize a roof in California?

Aim for October or November, after most leaves have dropped but before steady rain begins. In the Sierra foothills and mountain towns, finish earlier. If you have big deciduous trees near the house, plan on a second gutter cleaning after they finish dropping leaves.

To winterize a roof in California mostly means clearing water paths and catching weak spots early. You are not insulating against snow like in colder states. You are getting ready for long rain, wind and debris.

What is safe to do yourself, and what isn't?

Most of this checklist can be done from the ground, a sturdy ladder at the gutter line, or inside the attic. Walking on the roof is a different story. Stop and hire a pro if any of these are true:

• The roof is steep. If you can't comfortably walk up it standing straight, stay off it.
• The roof is tile, slate or wood shake. Tile cracks under your weight, and broken tile is how leaks start.
• The roof is wet, dewy or covered in moss. Wet roofs are slippery.
• The house is two stories or more.
• There are power lines near the roof, gutters or trees. Keep ladders and poles well away and call your utility for lines touching trees.
• You are working alone. Have someone hold the ladder and stay nearby.

If in doubt, the safe answer is to look, take photos, and let a licensed and insured roofer do the climbing.

How do you clean gutters before rain?

Gutters are the single most useful thing to clean before rain. A clogged gutter overflows at the roof edge, soaks the fascia board and can push water under the first row of shingles.

1. Set your ladder on firm, level ground and never stand on the top steps.
2. Scoop out leaves, needles and sludge with gloves or a gutter scoop. Bag it instead of dumping it in the flower bed by the foundation.
3. Flush each gutter with a garden hose, starting at the far end from the downspout.
4. Watch the water. It should flow toward the downspout without pooling. Standing water means the gutter has lost its slope.
5. Look for leaks at seams and corners, and for loose hangers or gutters pulling away from the house.

Our guide to clogged gutters and roof drainage explains what happens to fascia, siding and foundations when gutters fail.

How do you check downspouts?

A clean gutter does no good if the downspout is blocked. Run the hose into the top of each downspout. If water backs up, try flushing from the bottom or using a plumber's snake. Then look at where the water goes. It should empty onto a splash block or extension that carries it away from the house, not into a puddle against the foundation. If downspouts tie into underground drains, make sure the water comes out at the other end.

What should you look for on the roof from the ground?

Walk around the house with binoculars, or use a phone camera with zoom. Look for:

• Missing, curled, cracked or lifted shingles
• Bare spots where shingles have lost their granules
• Cracked, slipped or missing tiles
• Piles of leaves or needles in valleys and behind chimneys
• Flashing that looks bent, rusted or pulled away at chimneys, walls, skylights and vents
• Cracked rubber boots around plumbing vent pipes
• Sagging rooflines or ridges

Take photos of anything that looks wrong. They help a roofer give you a closer estimate, and they give you a dated record if you need to make an insurance claim later. If you see several of these, read our guide to the signs you need a new roof.

How do you check the attic for roof leaks?

The attic tells you what the outside can't. Go up on a sunny day with a good flashlight, step only on framing or walkways, and look for:

• Daylight through the roof boards, other than at vents
• Water stains or dark streaks on the underside of the roof deck and rafters
• Damp or matted insulation
• Mold, mildew or a musty smell
• Rusty nail tips, which can mean moisture is condensing up there
• Blocked vents. Insulation pushed against soffit vents traps moisture.

Check ceilings downstairs too, especially near chimneys, skylights and exterior walls. Old stains often come back with the first storm.

Should you trim trees before winter storms?

Yes. Branches that touch or hang over the roof drop leaves into gutters, scrub shingles in the wind, keep the roof shaded and damp so moss grows, and give rodents a path in. Dead branches can break off in a storm. Trim small branches you can reach safely from the ground. For large limbs, big trees or anything near power lines, hire a tree service. Tree work near lines is utility or specialist work, not a weekend project.

What should you leave to a licensed roofer?

• Replacing shingles, tiles or flashing
• Resealing chimneys, skylights and walls
• Any repair that needs you on the roof
• Moss treatment on steep or fragile roofs
• Anything involving the roof deck or structure

In California, a contractor needs a California contractor license from CSLB for any job of $1,000 or more in labor and materials. Before you sign, check the license, confirm they are licensed and insured, and ask the questions to ask a roofer before hiring. A ConFacts report puts a roofer's license and CSLB record in one place with a Trust Score, so you can check them before you sign.

Frequently asked questions

How often should I clean my gutters in California?

At least once a year before the rains. Homes under big trees often need it two or more times.

Can I pressure wash my roof?

It's usually a bad idea. Pressure washing can strip granules from shingles and force water under tiles. Ask a roofer about safer moss and algae treatments.

Is a roof inspection worth it before winter?

For older roofs, roofs that leaked before, or homes that just went through a hot summer, yes. A small repair in the fall usually costs less than water damage in January.

Can I patch a leak myself with roofing tar?

A dab of sealant can be a short term fix, but it often hides the real problem. Have a roofer find the source.

Do gutter guards replace cleaning?

They cut down on cleaning, but they still need checks. Fine debris and needles can collect on top of them.