Valley leaks
Where two roof slopes meet
Attic ventilation works as a pair: intake low at the soffits, exhaust high at the ridge. Get the balance wrong — or block the intake with insulation pushed into the eaves — and the roof space stops breathing. The result shows up as condensation on the underside of the decking, as shortened shingle life from trapped heat, and in colder parts of the state as ice damming, because a warm roof melts snow that then refreezes over the cold overhang. A lot of apparent leaks are actually ventilation problems.
Gridley gets the full range — freeze-thaw cycling through winter, severe convective storms with hail and straight-line wind in spring and summer, and enough temperature swing between them to work every joint on the roof loose. Freeze-thaw is the quiet one: water finds a hairline gap in flashing, freezes overnight, expands, and opens it slightly wider, repeating through a McLean County winter until a joint that was watertight in October is leaking by March. Spring brings the loud damage, and derechos have put straight-line wind through this region at speeds that take ridge caps and whole shingle courses. Housing stock here is older than average, which means a lot of roofs where the flashing has already been through several decades of that cycle.
Gridley has a population of about 1,456, and the housing stock here sets the pattern for what fails first on a roof.
Routinely. Condensation forming on cold decking drips onto insulation and shows up as damp patches that behave almost exactly like ingress. The tell is that it tracks cold weather rather than rain.
No. Mixing exhaust types — ridge vents and powered fans, say — can make a fan pull air from the ridge instead of the soffits, which short-circuits the whole system. Balance between intake and exhaust matters more than total area.
Where two roof slopes meet
The metal that seals every joint
Condition assessment and report
Bruising and granule loss
Keeping debris out of the gutter
Lifting panels for roof work
You will get a straight answer on whether Gridley needs someone out today or whether it can wait — before anyone quotes you for anything.
Call (706) 696-1888