A Frame Attic Ventilation
The soffits are closed but are not insulated.
A frame attic ventilation. Here are six of the most common misconceptions about attic ventilation. Photo courtesy jonathan sinclair. If i have roof vents i have good attic ventilation. The space above the top plate of exterior walls at the bottom of each rafter bay is especially important.
The homeowner wonders whether his plans include an adequate amount of ventilation for the attic. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. Help protect your roof system from premature deterioration by installing a properly balanced attic ventilation system consisting of cobra exhaust vent at the ridge and adequate intake ventilation at or near the soffit areas of your roof. November 19 2014 8 52pm 1.
The molded polystyrene baffles available at home centers and lumberyards for about 1 each form channels that hold insulation at bay and direct incoming air upward. You can also contact your local municipality to check on building code in your area. This article will help you determine if your attic is properly ventilated and show you. Most building codes require a ratio of 1 150 ventilation space to attic floor space.
Roof ventilation for a frame. In other words the entire vent opening doesn t count as vented space. The success of a vented attic or roof deck relies on its airtightness. Active ventilation and what you really need to do to have a well vented attic space that stays cool and dry.
If only it were that simple. Can you have too much ventilation in your attic. This timber frame home in new hampshire is getting new siding over a vented rainscreen. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.
Adequate roof ventilation reduces cooling bills extends shingle life and prevents roof rot and ice dams in winter. Read on to find out what you need to know about attics soffit vents passive vs. Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation. Both roof and soffit vents are easy to install in just a few hours.
That said air resistance and interference such as vent grates reduces the area of true ventilation. Jonathan sinclair s home a 225 year old timber frame in new hampshire is getting a facelift. How would you ventilate an a frame roof with eight inches of attic space filled with insulation after a redeck with composite shingle. Roof and attic ventsl protect your house from expensive future repairs.