What is storm damage to a roof?
Storm damage is harm caused by a single weather event rather than by age: shingles, ridge caps and flashing lifted or torn by wind, punctures from falling limbs or whole trees, and the water that gets in through those openings. It is different from wear, which builds slowly, and insurers and roofers treat the two separately.
In Marin, the storms that cause it are the strong winter systems often called atmospheric rivers. They bring long bands of heavy rain and gusty wind. In January 2021 one such storm brought gusts of 61 miles per hour to Lucas Valley and Marinwood and 73 in Woodacre, and left hundreds of Novato customers without power. The National Weather Service's write-up of the January 2017 storms included a photo of a tree that fell on a house in Novato.
Trees are the main difference between storm damage here and on open plains. Mature oaks, eucalyptus, pines and redwoods stand close to many Marin homes, and saturated soil after days of rain makes them easier to topple.
How storm-damaged roofs are repaired
Storm repairs happen in stages, because the weather usually does not allow everything at once.
- Make it safe. Downed lines are handled by the utility, and large limbs or trees are removed by a tree service before roof work begins.
- Document. The roofer photographs every damaged area, inside and out, before anything is moved or covered.
- Dry-in. Openings are covered with tarps fastened over boards, or with temporary underlayment and patches, to stop water until a dry window.
- Structural repair. Broken rafters, cracked decking and damaged fascia are replaced where a limb hit.
- Roofing repair. Torn or lifted shingles are replaced, loose tabs sealed, ridge caps rebuilt and flashing reset.
- Interior follow-up. Wet insulation is removed and ceilings dried before they are repaired.
Eight signs a storm damaged your roof
- Shingles, ridge caps or pieces of flashing in the yard
- A limb on the roof or scrape marks along the eaves
- Exposed underlayment or bare wood visible from the ground
- Shingle tabs that look raised, creased or out of line
- Gutters bent or pulled away from the fascia
- New stains in more than one room after the storm
- Daylight through the roof deck seen from the attic
- A sagging section of roof or ceiling under an impact point
How Marin storms damage roofs
Wind works on the edges first. As gusts move over a roof, they create suction that is strongest at the eaves, rakes, corners and ridge. Shingles with weak seal strips lift, and once a few are loose, the next gust peels more. Ridge caps on exposed hilltop homes take the hardest hits.
Trees cause the most serious damage. After days of soaking rain, the ground around roots softens, and a strong gust can tip a tree or drop a heavy limb. Eucalyptus and oaks are known for dropping limbs, and a single branch can crack rafters and punch through decking.
Rain finishes what wind starts. Atmospheric river storms can bring hours of steady, wind-driven rain, which pushes water sideways into every opening the wind created. That is why roofs that came through the wind looking fine can still leak by the end of the storm.
What to do first after a storm
- Make sure everyone is safe; stay away from downed lines and call 911 or PG&E if you see one.
- Keep people out of rooms below a tree strike or a sagging ceiling.
- Photograph the outside from every side of the house and every interior stain, with dates.
- Catch water with buckets and move valuables away from drips.
- Call your insurer to start a claim and note the claim number.
Take a slow video walking around the house and through each damaged room before any cleanup. Narrate the date and what you see. It is faster than photos and shows the adjuster the full picture.
The roofer's visit after a storm
- Safety check. The roofer confirms the structure is safe to work on and that any tree has been removed or stabilized.
- Photos. Damage is documented slope by slope, including lifted tabs that are hard to see.
- Temporary cover. Openings are dried in if more rain is coming.
- Attic and structure. Rafters, decking and fascia are checked from inside.
- Written scope. You get a scope that separates storm damage from older wear, useful for the claim.
- Repair. Permanent work is scheduled in a dry window.
What shapes a storm repair
| Factor | Effect |
|---|---|
| Tree impact | Structural damage brings in framing work and often a tree service. |
| Extent of wind damage | Spot repairs versus replacing whole slopes. |
| Insurance process | Adjuster visits and approvals affect timing. |
| Weather | Back-to-back storms can delay permanent repairs. |
| Fire-area rules | Larger reroofs in hazard areas generally need Class A. |
Trees near the roof: what to watch before the next storm
Most serious storm calls in Marin start with a tree. Before the wet season, look up at any tree whose limbs reach over the roof. Dead branches, cracks where a large limb joins the trunk, mushrooms at the base and soil heaving on one side after rain are all signs worth showing a certified arborist.
Trimming limbs back from the roofline also helps between storms. It cuts the debris that clogs valleys and gutters, lets the roof dry faster and keeps branches from scraping shingles in the wind. In fire hazard areas, keeping branches clear of the roof is part of standard defensible-space advice as well, so one round of trimming serves both seasons.
Photos, claims and paperwork
Keep one folder for the storm: photos and video, the claim number, the adjuster's name, receipts for tarps and tree work, and the roofer's written scope. If the adjuster's list and the roofer's list differ, ask the roofer to point out each item in photos.
Before signing with anyone, look up their license with the California Contractors State License Board and ask for proof of liability insurance. After big storms, out-of-area crews knock on doors; take time to check anyone before you agree to work.
When storm damage is an emergency
It is an emergency when a tree or large limb is on the house, when there is an open hole with rain falling, when ceilings are bulging or water is near electrical fixtures, or when any part of the structure looks unstable.
A tree through the roof or walls that look shifted means everyone leaves the house and someone calls 911 from outside. Stay clear of downed power lines. Do not climb onto a storm-damaged roof; decking may be cracked and debris may shift.
Storm damage questions
Who removes a tree from my roof, the roofer or a tree service?
A tree service removes large trees and limbs, ideally with care not to drag them across the roof. The roofer then covers the opening and repairs the structure and roofing. Some situations need both on site together.
Is wind damage covered by homeowners insurance in California?
Many policies cover sudden wind and falling-tree damage, but terms vary widely. Check your own policy or ask your agent, and document everything before repairs begin.
My shingles look fine after the storm. Could the roof still be damaged?
Yes. Strong gusts can break the seal under shingle tabs without removing them. Those tabs leak in the next wind-driven rain, so a check after a major storm is worth it.
Can permanent repairs happen during the rainy season?
Small repairs can be done in dry breaks between storms. Larger work may wait for a longer dry stretch, with the roof covered in the meantime.
Do I need a permit to repair storm damage?
Small repairs often do not, but replacing large areas of roofing or structural members usually does, and in fire hazard areas larger reroofs generally have to meet Class A. Ask the roofer and the building division.
How do I avoid storm-chasing contractors?
Be cautious with anyone who knocks after a storm asking for large payment up front. Look up their California contractor license with the CSLB and ask for proof of insurance before signing anything.
Related pages
If there is an opening and rain is on the way, start with emergency tarping. San Anselmo's creekside neighborhoods and mature trees make storm season a bigger worry there, as the San Anselmo page explains.
Mill Valley homes under tall redwoods and oaks face the same tree risk, covered on the Mill Valley page. The Marin storm season guide on the home page shows when in the season these storms usually hit.