The Town of Prescott Valley publishes the design criteria its plans examiners use under the 2018 International Residential and Building Codes. A few of those numbers describe exactly what a roof here is expected to face in winter: a roof live load of 30 pounds per square foot covering roof and ground snow, a winter design temperature of 15°F, a rainfall rate of 4 inches per hour, a basic wind speed of 115 mph for homes built under the residential code, and a mean elevation of 5,026 feet.
What these numbers mean, and what they do not
They are design minimums for new construction and permitted work. They tell you the conditions the town plans around. They do not tell you how an older roof is holding up today. Worn shingles, loose flashing, or a clogged gutter can fail well short of the design numbers.
Timing matters too. As of October 22, the NWS forecast for Prescott Valley shows mostly sunny days and overnight lows in the low 40s from Friday through next Wednesday. That is a useful dry stretch for pre-winter work.
A pre-winter checklist tied to those numbers
- Rain at 4 inches an hour: clear gutters, downspouts, and roof valleys of needles and leaves. Make sure downspouts carry water away from the foundation.
- Snow load: look from the ground for sagging along the ridge or between rafters. After a heavy snow, watch for interior doors that suddenly stick. Do not climb onto a snowy roof to clear it.
- Cold nights: check the attic for gaps in insulation and blocked soffit vents. Warm air leaking into the attic can melt snow that refreezes at the eaves.
- Wind: look for lifted shingle edges, loose ridge caps, and flashing that has pulled away at walls and chimneys.
- Branches: trim limbs that overhang the roof before snow weighs them down.
- Penetrations: check the seals around vent pipes, skylights, and the chimney.
For the fire side of roof edges and gutters, see our earlier post on Prescott Valley wildfire readiness at the roof edge.
Get a second set of eyes
Apex Roofing Systems inspects roofs across Prescott Valley. To request a free roof inspection before winter, use our contact page or call (480) 808-ROOF (7663).
Sources: Town of Prescott Valley, 2018 Codes Design Criteria; National Weather Service forecast for Prescott Valley.