About 80% of Modesto's rain falls November through March, and January is the wettest month. Check your roof in September or early October: clear gutters and valleys, look for cracked or slipped tiles and lifted shingles, check flashing and vent boots, and inspect the attic for stains.
When should I check my roof?
In September or early October. Modesto averages about 12.3 inches of rain a year, about 80% of it from November through March, with January the wettest month. (Source: NOAA 1991–2020 climate normals) Fixing a $200 problem in a dry September beats tarping a leak during a January storm.
The 10-point checklist
Do everything you can from the ground, a ladder at the eaves, and inside the attic. Leave walking the roof to a pro, especially on tile.
1. Gutters and downspouts
Clear leaves and roof grit; flush downspouts and make sure water discharges away from the foundation.
2. Valleys
Valleys collect the most water and debris. Look for leaf build-up and rusted or exposed valley metal.
3. Shingles
From the ground with binoculars: curling, missing or lifted tabs, and bare spots where granules have worn off.
4. Tiles
Cracked, slipped or missing tiles, and any spot where you can see underlayment between tiles.
5. Flashing
Where the roof meets walls, chimneys and skylights: gaps, lifted metal or dried-out sealant.
6. Vent pipe boots
The rubber collars around plumbing vents crack in the sun and are among the most common leak sources.
7. Attic
On a bright day, look for daylight through the decking and for dark stains or damp insulation.
8. Ceilings
New or growing stains, especially near exterior walls and below valleys.
9. Trees
Branches over the roof drop debris and can break tile in wind. Trim back at least six feet.
10. Solar arrays
Leaves and nests collect under panels and block drainage; check mounts for gaps in flashing.
Should I do it myself or hire a pro?
Do the ground, gutter and attic checks yourself; hire a pro for anything on the roof surface. Tile breaks under foot and steep shingle roofs are a fall risk. Our homeowner roof inspection is free.
What should I document after a storm?
Photograph damage with timestamps before cleanup, note the date and time of the storm, and keep receipts for any emergency tarping. Insurers generally cover sudden storm damage, not wear. (Source: California Department of Insurance)
About the author
Dan Whitfield, Field Superintendent. Dan runs the installation crews and signs off every roof before final inspection. Twenty years on tile, shingle and low-slope commercial roofs.
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