Therefore, it is important never to block off sources of roof ventilation, such as louvers, ridge vents or soffit vents, even in winter. Proper attic ventilation will help prevent structural damage caused by moisture, increase roofing material life, reduce energy consumption and enhance the comfort level of the rooms below the attic.
In addition to the free flow of air, insulation plays a key role in proper attic ventilation. An ideal attic has:
▸ A gap-free layer of insulation on the attic floor to protect the house below from heat gain or loss
▸ A vapor retarder under the insulation and next to the ceiling to stop moisture from rising into the attic
▸ Enough open, vented spaces to allow air to pass in and out freely
▸ A minimum of 1 inch between the insulation and roof sheathing
The requirements for proper attic ventilation may vary greatly, depending on the part of the United States in which a home or building is located, as well as the structure's conditions, such as exposure to the sun, shade and atmospheric humidity. Nevertheless, the general ventilation formula is based on the length and width of the attic. NRCA recommends a minimum of 1 square foot of free vent area for each 150 square feet of attic floor—with vents placed proportionately at the eaves (e.g., soffits) and at or near the ridge.
Proper roofing ventilation will save you money in the long run. Minimizing heat in your attic space will reduce the amount of cooling you will have to do during the summer months and reduce moisture in the winter. A good roofing ventilation system will provide an equal amount of air in and out. In addition to having roofing vents or ridge vents (at the top of your roof) which let the hot air escape, you also need to have intake vents or soffit vents that allow air to pass in from the bottom.
Generally, you should have at least the same amount of intake as you have exhaust. A good rule of thumb is to have 1 square foot of ventilation for every 150 square feet of attic space; half should be intake and half exhaust.
When you have questions about roofing including proper ventilation, give Hodges Roofing a call. We are experts in insuring you have the best roofing system to protect your most valuable asset.