Attic Ventilation

What This Service Involves

In our marine climate, warm indoor air loaded with humidity rises into the attic and condenses on cold roof decking, leaving frost lines and dark water stains by mid-winter. A properly balanced system pairs low soffit intake with high ridge or roof exhaust so that damp air is continuously flushed before it can soak into the plywood. We calculate the net free vent area against your attic square footage using the 1/300 rule and correct the common local problem of exhaust vents with no matching intake. The result is drier framing, less mold pressure, and a roof deck that reaches its full service life. Every assessment includes a look at insulation depth and bath-fan routing, since blocked soffits and fans dumping into the attic are the usual culprits behind Washington condensation.

Benefits

Stops winter condensation from rotting your roof decking; extends shingle and sheathing life in a wet climate; lowers summer attic heat that bakes upstairs bedrooms; reduces mold and mildew growth in humid PNW air; helps prevent ice dams during cold snaps in the foothills

Our Process

1) Inspect the attic for moisture staining, blocked soffits, and existing vent net-free area; 2) Calculate the required intake and exhaust balance for your attic footprint; 3) Add or clear soffit intake and install matched ridge or roof exhaust; 4) Reroute stray bath and kitchen fans to the exterior and verify airflow

What Affects the Cost

Attic size and roof pitch; how much existing intake must be added or unblocked; vent type selected such as ridge, static, or powered; number of bath fans needing exterior ducting; whether insulation baffles are required to keep soffits clear

Best Time of Year

Fall is the ideal time to correct ventilation before the wet season drives months of condensation into your attic.