How Monterey Park's climate quietly wears a roof down
Roofs in Monterey Park rarely fail all at once. They wear in slow motion, season by season, and the cause is the same combination that defines weather across the west San Gabriel Valley. Summer here means months of intense, direct inland sun with very little relief, and that heat does real damage. On an asphalt roof it dries out the shingles and drives off the protective granules; on a tile roof the tiles themselves hold up, but the underlayment beneath them cooks and grows brittle long before anything looks wrong from the curb.
Then the season turns. The Santa Ana winds arrive in the fall, accelerating as they push down out of the foothills and through the valley, lifting edges and working loose anything that summer already softened. Winter follows with rain that does not come gently here, it comes in heavy bursts that overwhelm clogged gutters and find any gap a windy fall opened up. Each phase hands off to the next, and a roof that looked fine in spring can be leaking by the following winter.
Because that wear is uneven, the part of the roof you can see from the sidewalk tells you almost nothing. The south and west faces take the worst of the sun, the leeward edges take the worst of the wind, and the low valleys take the worst of the rain. We inspect all of it, including the planes and details a quick look from the ground will always miss.