Walk around the house
- Shaded slopes: thick moss and lifted shingle edges.
- Valleys: packed redwood or oak litter, dark stains.
- Eaves: soft or sagging edges.
- Near the water: rusty nails, flashing and gutters.
- Sunny slopes: bald or cracked shingles.
Inside
Look in the attic after a storm for wet sheathing, mold spots or drips along nails.
What Marin roofers report
Marin roofers commonly see moss and packed debris in valleys under trees in Mill Valley, Fairfax and the San Geronimo Valley, corroded flashing and fasteners near the bay and the coast, sun-cracked shingles on exposed Novato and San Rafael slopes, and older wood shake that may not be replaced in kind in a fire-hazard area.
Before you call
Note which rooms leak and when. Leaks only in wind-driven rain point to flashing and ridges; leaks after every rain point to the field of the roof.
Every roofer we work with is licensed, insured and highly reviewed by Bay Area homeowners.
Get a free replacement quoteFrequently asked questions
Are needles in my valleys a big deal?
They hold water and debris against the roof. Packed valleys are a common leak source in Marin.
Is green staining moss?
Often algae or moss. Moss that lifts shingles is the bigger concern.
Should I inspect before fire season too?
Yes. Clearing debris helps both with leaks and with ember risk.
Sources
Sources reviewed November 11, 2026. Figures are published estimates and official fees, not quotes. Confirm prices, permits and requirements with your contractor and building department. This page is general information, not legal or insurance advice.