Attic Ventilation Worksheet Fresno

Calculations are based on 1 square foot of net free area for every 150 square feet of attic floor space.

Attic ventilation worksheet fresno.

See attic ventilation worksheet typical values for attic vents soffit vents 3 5 x 14 5 30 sq ins 3 5 x 22 5 50 sq ins 5 5 x 22 5 80 sq ins small dormer vents 50 sq ins large dormer vents 100 sq ins ridge vents per icc evaluation report. A minimum of 1 inch 25mm of air space shall be provided between the insulation and the roof sheathing. The rvk1a steel roof cap kit is an the rvk1a steel roof cap kit is an easy to install vent for ventilation fans bath rec room home gym etc. Attic ventilation calculator note.

1 300 of the attic floor area. Effective attic ventilation systems reduce damaging heat and moisture in your attic promote energy efficiency by helping to reduce the load on your air conditioner in the summer and also reduce the risk of ice dam formation on your roof. Select the roof pitch that is closest to yours. 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 net free ventilating area shall not be less than 1 300 of the area of the space ventilated. Up to 6 12 7 12 to 10 12 11 12 and up. 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. Distributed equally around the structure.

Current cbc requirement is 1 300 of the attic floor area. Other options to meet your attic ventilation needs are. See attic ventilation worksheet typical values for attic vents soffit vents 3 5 x 14 5 30 sq ins 3 5 x 22 5 50 sq ins 5 5 x 22 5 80 sq ins small dormer vents 50 sq ins large dormer vents 100 sq ins ridge vents per icc evaluation report. Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator.

If you are in the puget sound area of washington state and would like to have a free attic ventilation evaluation or roof estimate please contact us at 253 445 8950 or fill out our quick estimate form. This cap features both a back draft damper and bird screen preventing outside air from entering the home and birds and small pests from entering duct work. See attached required attic ventilation shall be provided for all reroof projects as determined from the attic ventilation worksheet. It is compatible with 3 or 4 ductwork and includes a 3 to 4 adapter for convenience.

Ventilation attic spaces cont. Calculate or enter the square footage of the attic or area to be vented. Standard attic vents like af 50 s ventilation fans or solar powered attic fans.