Construction practices and products have changed dramatically in recent decades. Windows and doors are more airtight, insulation levels have increased and the use of house wraps and vapor retarders is commonplace. Today’s houses are more airtight and that helps save energy. But these changes have created new issues with indoor air quality and attic ventilation.
As construction has changed, code requirements have not always kept up. Heat or moisture problems can develop in the attic, even when the contractor has installed an attic ventilation system up to code. At the same time, shingle manufacturers are requiring “proper attic ventilation” to validate shingle warranties. That is why it’s never been more important for contractors to know, understand and apply all the aspects of attic ventilation.
RK Roofing as pro-active contractor always inspects and corrects (if necessary) your attic ventilation system as it directly impacts your roof performance over time.
Principles of roof/attic ventilation:
- Ventilation is a system of intake and exhaust
- Air follows the path of least resistance
- Air should enter the attic at the lowest point possible
- As the air heats up and rises it should exit at or near the ridge
- Balanced ventilation system means at least 50% of the required vent area must be intake and 50% exhaust
- Make sure intake & exhaust vents are clear of any debris
- Use insulation baffles as required to the air path
- Difference between ventilating Hip and Gable roofs
- Use of air channels for ventilating cathedral ceilings
- Preventing ice dams
- Proper ventilating of knee wall area
- Knowing which products to use for the best performance;
Ridge vent, static (mushroom) vent, power fan, gable louvers, wind turbines