How to get a San Jose roof ready before the rains

Why fall is the time

About 82 percent of San Jose's yearly rain falls between November and March, and summer months normally see only about a fifth of an inch. The city averages roughly 15 inches a year, sitting in the rain shadow of the Santa Cruz Mountains, but that rain tends to arrive as atmospheric rivers, heavy storms that come in groups. The last two winters brought back-to-back storms with no dry time between them, and in strong El Nino years the wet season runs longer still.

The long dry summer is the other half. Some 3,400 hours of sun a year dry out sealants, crack rubber pipe boots and loosen shingle edges, so the roof is at its weakest just before it is tested.

What to check from the ground

Walk around the house with binoculars on a clear day. Look for missing or lifted shingles, tiles out of line, flashing peeled back at walls and chimneys, and dark streaks below gutters that show water running behind them. Look at the gutters themselves for sagging runs and at downspouts for loose elbows. Check that downspouts discharge away from the foundation.

Do not climb onto the roof to look. Pitched and tile roofs are easy to fall from and easy to damage.

Gutters and downspouts first

Clogged gutters are the most common cause of avoidable winter water damage we see. Leaves and grit from the roof pack the troughs and the downspout elbows, and the first heavy storm sends water over the front edge and behind the fascia. A clean-out in October, after most leaves drop, is the single most useful thing on this list. Our gutter cleaning visits flush every downspout and note anything that needs repair.

A look in the attic

If you have attic access, take a flashlight up on a dry day. Look at the underside of the roof deck for dark stains, especially around vents, chimneys and skylights, and at the insulation for flattened or discolored patches. Old stains that are dry and firm may be from leaks already fixed; soft or dark wood means something is still getting in. Photograph what you find so the roofer can start there.

What a roofer checks on a fall visit

A fall roof maintenance visit walks every slope and checks the details that fail first: pipe boots, vent and skylight flashing, chimney and wall flashing, valleys and the edges. Cracked boots are replaced, loose shingles re-adhered, slipped tiles reset and debris cleared from valleys and behind chimneys. Anything larger is photographed and priced, so you can decide before the weather decides for you.

For older roofs, or if you are unsure about the roof's overall condition, a full roof inspection with a photo report gives you the whole picture.

A simple fall checklist

Use this as a quick run-through each October.