Roof Ventilation in Virginia

What this service includes

• Ventilation assessment and net-free-area calculation
• Soffit and intake vent correction
• Ridge, box or powered exhaust vent installation
• Attic insulation and air-sealing coordination

Warning signs

• Ice dams in winter
• Very hot attic in summer
• Condensation or frost on the underside of the deck
• Musty odour or visible mould
• Premature shingle ageing

Common causes

• Blocked soffit vents
• Insufficient intake for the exhaust installed
• Mixed exhaust types short-circuiting airflow
• Bath and dryer vents terminating in the attic

Systems and materials involved

• Ridge vent
• Soffit intake
• Gable vents
• Powered and solar attic fans

Repair or replace?

Ventilation is usually corrected during a roof replacement, but intake problems can often be fixed independently at lower cost.

How the work is carried out

1. Attic assessment
2. Net-free-area calculation
3. Intake correction first, then exhaust
4. Verification of airflow
5. Documentation

What affects the cost

• Roof and attic size
• Soffit accessibility
• Whether insulation must be moved or baffles installed
• Type of exhaust vent

Virginia-specific considerations

Virginia's summer humidity makes attic moisture control as important as heat control. In the Shenandoah Valley and mountains, ventilation is the primary defence against ice damming.

Questions to ask contractors

• What is my current intake-to-exhaust ratio and what should it be?
• Are my soffit vents actually open, or blocked by insulation?
• Are any bathroom or dryer vents discharging into the attic?
• Are you licensed in Virginia, and what is your license number?
• Can you provide a current certificate of general liability and workers' compensation insurance?
• Who pulls the permit, and which jurisdiction issues it?
• What is included in the written scope - underlayment, flashing, ventilation, decking allowance and disposal?
• What warranty covers workmanship, and what covers materials?
• Who will be on site each day, and is the crew employed by you or subcontracted?