Required Ventilation In Attic

The federal housing authority fha and the urban development hud have established minimum requirements for attic ventilation.

Required ventilation in attic.

Allows cool dry air to enter the attic. 1500 150 10 so if this is the minimum is it ok to have more. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space. You can also contact your local municipality to check on building code in your area.

Most building codes require a ratio of 1 150 ventilation space to attic floor space. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. For the best results place roof ventilation near the roof s peak and soffit vents in the eaves. Hence you would need two square feet 600 300 of attic ventilation.

This means that if you have a 1500 sq attic then you would need at least 10 sf of ventilation. Grab a flashlight and inspect your attic during the winter. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space. The following product options will allow you to achieve an intake nfva of 528 square inches.

Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge. Current regulations state that the minimum attic ventilation requirements are 150 1. Enclosed attics and enclosed rafter spaces formed where ceilings are applied directly to the underside of roof rafters shall have cross ventilation for each separate space by ventilating openings protected against the entrance of rain or snow. There should also be a 50 50 balance of attic venting and roof venting.

Attic ventilation is an important part of keeping your building healthy. According to the fha federal housing administration us for every 300 square feet of attic floor area you should have at minimum one square foot ventilation. Regarding attic ventilation nrca recommends designers provide at least 1 square foot of nfva for every 150 square feet of attic space 1 150 ventilation ratio measured at the attic floor level ceiling. If you see dampness or frost you need better roof ventilation and some attic vents.

Choose one of the following products to meet the recommended intake nfva of 528 square inches. Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge. As an example in an attic that is 30 feet by 20 feet you would have 600 square feet of floor area.