Ridge Vent vs. Soffit Vent: Why We Measure Both Before We Bid

Before we bid a roof, we climb up and measure the ridge. On a recent job the opening along the peak was approximately two inches. That number tells us how much hot air the attic can push out, and it tells us how much fresh air has to come in at the bottom to keep things balanced.

Exhaust and intake are two halves of one system

A ridge vent is exhaust. It lets hot, moist air leave at the highest point of the roof. But air only flows out if air can flow in, and that happens through the soffit vents under the eaves. If the ridge is wide open and the soffit is blocked or undersized, the attic cannot move air the way it should.

What we measure before we bid

• The width and length of the ridge opening, which sets how much exhaust the roof can have.
• The soffit vents already in place, and whether they are open, blocked by insulation, or missing.
• The size of the attic, since larger attics need more total ventilation.
• Whether other exhaust vents, such as box vents, are on the roof and should be removed or covered when a ridge vent goes in.

Why it matters for your roof

• Summer heat builds in the attic and bakes the shingles from below.
• Winter moisture condenses on the underside of the deck and can lead to mold or rot.
• Warm attics can contribute to ice dams along the eaves.

Questions to ask any roofer

• How much ridge opening and how much soffit intake will my roof have?
• Are the soffit vents actually open, and will insulation be kept clear of them?
• Will you remove or cover old vents when you install a ridge vent?
• Is the ventilation plan written into the estimate?

We measure first, then quote

Gerkin Construction checks ridge and soffit ventilation on every roof we bid across Lawrence and Orange Counties. If you are planning a replacement, or just want to know whether your attic is breathing, contact us for a free inspection.