Properly sizing and placing intake and exhaust vents for a wood shake roof is essential for maintaining good attic ventilation and prolonging the life of the roofing materials. Ventilation works by allowing cool air to enter through intake vents, typically located in the soffits or eaves, and warm, moist air to exhaust through vents near the ridge or higher points of the roof. For wood shake roofs, the general recommendation is to provide 1 square foot of net free ventilation area (NFVA) for every 150 square feet of attic space, split evenly between intake and exhaust vents. Because wood shakes can retain moisture, sufficient airflow helps prevent wood rot, warping, and mold growth. Simple diagnostics at home include checking the attic for signs of moisture buildup, condensation, or musty smells, especially after wet weather. You can also look under the roof for visible daylight through vents to confirm they are not blocked and ensure that ventilation happens uniformly along the roofline rather than being concentrated in one spot.
Basic DIY checks involve inspecting soffit vents to ensure they’re clear of paint, debris, or insulation that might block air intake, and making sure ridge vents or other exhaust vents are open and unobstructed. However, because incorrect vent placement or sizing can reduce energy efficiency and void certain warranties, it’s wise to call a professional roofer if you notice persistent moisture problems, wood discoloration, or uneven roof aging. When consulting a contractor, ask specifically how they calculate the NFVA for your attic size and whether they will balance intake and exhaust to optimize airflow. Another helpful question is whether the vent system complies with the wood shake manufacturer’s requirements and local building codes, as this can impact roof warranty coverage and long-term performance.