Calculating Attic Size

Input length width and desired r value of the area to be insulated.

Calculating attic size.

Measure the height of your attic in feet. Cfm cubic feet per minute is a measure of the amount of air the fan moves in a minute. Calculate or enter the square footage of the attic or area to be vented. 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.

I ll do this on the right side of the house which is a 12 12 pitch. So draw up a simple cross section showing the outside wall a rafter set at the correct pitch and a floor system. It s the covering on the uppermost part of the building or shelter which gives protection from pets or animals and weather notably rain or snow but heat also sunlight and wind. Pitch measurement method 2.

Measure the length of your attic in feet. This attic ventilation calculator computes the size and number of solar powered attic fans to achieve the proper ventilation for your attic. Attic truss room size calculator a rooftop is part of a building envelope. Next multiply the square feet of attic space by 0 7 to get the minimum number of cubic feet of air per.

How to calculate the cubic feet of an attic. How to size attic exhaust vent fans for your home attic size. The formula above gives an approximate value of the cfm needed for an attic fan. Attic fan size cfm 0 7 x sq ft area of the attic formula 1 the size of an attic fan is calculated in terms of cfm.

Divide this number by two. 8 inches and you have an 8 in 12 pitch. On a ladder beside the roof place the level a foot or so up the roof hold it level and measure from the 12 inch mark on the level s bottom straight down to the roof. Click to see full size image.

Next we need to calculate the 5 and 8 ceiling lines. Measure the length and width of the attic floor space to be ventilated. This calculator is to be used as an estimating tool only. To determine the size of your attic multiply the width by the length of the attic floor in feet.

Measure the width of your attic in feet. If this distance measures 4 inches you have a 4 in 12 pitch. Click the button to calculate the depth in inches and pounds of total insulation required for this job.