Attic ventilation: questions before roof replacement

Before approving a roof replacement, ask the contractor to identify your attic’s design, explain where air enters and leaves, and list the ventilation work in the estimate. A line that says “new ridge vent” leaves the intake side unanswered.

For your home in Huntsville, Eden, or Liberty, bring any history of attic moisture or winter ice buildup to that conversation. Ask for inspection photos so you can discuss the findings without climbing onto the roof or entering an unfinished attic.

Is this attic intended to be vented?

In a typical vented attic, insulation sits at the ceiling and outdoor air moves through designated vents. An unvented attic has insulation along the roofline and a different approach to controlling condensation. The Pacific Northwest National Laboratory explains both designs in its vented and unvented attic guide.

If your home has spray foam beneath the roof deck, vaulted ceilings, or an addition with a separate roof space, ask the contractor to identify each assembly before proposing changes. Have the estimate say which areas the ventilation plan covers.

Where will air enter and leave?

For a vented attic, have the roofer mark intake and exhaust locations on photos or a sketch. Intake is usually near the eaves; exhaust is usually near the roof’s peak. GAF explains why the two need to be balanced in its ventilation planning guide.

Ask for the product names and sizing calculation. Net free ventilation area, or NFVA, measures the opening available for air to pass through a vent. GAF’s calculation uses attic floor area and vent ratings to determine quantities. Have the contractor explain the sizing requirements that apply to your home and how the selected products meet them.

Is the airflow path open?

Insulation can block soffit vents. Rafter baffles help keep a channel open from the eaves into the attic. ENERGY STAR’s attic ventilation guidance explains this connection and the importance of keeping insulation out of the intake path.

Ask whether the inspection checked that path and what needs correcting. Replacing a visible vent does not establish that the space behind it is clear. If access is limited, have the contractor record what could not be checked and when it can be assessed.

What happens to the existing vents?

Have the proposal identify which vents stay, which are removed, and how old openings will be closed. GAF’s technical bulletin on attic ventilation warns that combining different exhaust systems, such as a powered fan with ridge ventilation, can disrupt the intended airflow.

If a contractor proposes that combination, ask them to explain how it follows the selected products’ installation instructions. Leave alterations to the professional responsible for the plan.

Who handles insulation and air sealing?

ENERGY STAR explains that air sealing and insulation help limit heat and moisture moving from the home into the attic. Ventilation is one part of that work. If you have recurring ice at the eaves, share the history and use our winter-roofing guide to prepare for a broader assessment.

Before signing, get separate scope lines for:

• Roof vents and any closures of old openings.
• Soffit changes and baffle work.
• Attic air sealing or insulation, if recommended.
• Any separate assessment needed before the work can be priced.

Each line should name who handles it and whether its price is included, excluded, or still to be determined. Keep those answers with the rest of your roof-estimate comparison so you can resolve missing work before choosing a bid.