06:36PM | 12/12/03
Member Since: 08/15/03
7 lifetime posts
How many soffit vents I need for my attic?
Where can I find the R Values for NY state?

Length of attic = 52 ft
Width of attic = 22 ft
Height of attic = 6 ft


10:42AM | 12/17/03
Member Since: 01/21/03
66 lifetime posts
The ventilation rule I follow is to provide 1 sq.ft. of ventilation for every 150 sq.ft. of attic space. This needs to be balanced, so that 50% of ventilation forms the inlet at the soffits, and 50% forms the outlet at the vents. Perforated soffits have different degrees of penetration, some have as little as 0.01 sq.ft. of ventilation for every sq.ft. of soffit, and some have higher number up to 0.06 sq.ft.

Your attic is 52x22 = 1144 sq.ft. requiring 7.6 sq.ft. of ventilation (1144/150). 50% (or 3.8 sq.ft.) needs to come from the soffits. The perimeter around your house is roughly 150 ft. (52+52+22+22). Assuming that you have a soffit 1 ft. wide, you have about 150 sq.ft. of soffit. If you install ventilated soffits having clearance of about 0.03 sq. ft., you will have 4.5 sq.ft. (150 x .03) of effective ventilation, which is just a bit bigger than the 3.8 sq.ft. you need.

Is this what you were looking for?


01:21PM | 12/27/03
Member Since: 11/06/02
1281 lifetime posts
None of the "experts" agree on this one, but I usually see recommendations of one foot for every 100 to 150 SF of living space. It should be ballanced so there is as much exiting the ridge vent as ther is coming in the soffits or it will be next to worthless, but not cut in half.

In other words, if you have a thousand feet of living space, I would put in ten SF of soffit vent and ten SF of ridge vent.

If you use typical 2" soffit on both sides and 4" ridge, you will exceeed that.

[This message has been edited by Piffin (edited December 27, 2003).]



Post a reply as Anonymous

Photo must be in JPG, GIF or PNG format and less than 5MB.


type the code from the image


Post_new_button or Login_button

Handscraped finishes join the rustic, old-world feel of antique flooring with the durability and simplified installation b... Reused steel windows create an eye-catching splashguard in this walk-in shower. The vintage factory windows bring an inter... A galvanized steel tub is a surprising but charming fixture in this bright and breezy screened patio. It's perfect for was... If you're not crazy about the idea of commingling plants and pool, this modern variation may be more to your liking. The s... Yes, a freestanding garage can become its own tiny house. Artist Michelle de la Vega has all the comforts of a modern resi... If you lack plumbing skills but have a good sturdy tree, here's the easiest outdoor shower solution of all: Simply attach... Pursue what's known as the stack effect. To achieve it, open the windows on both the upper and lower floors, and as warm a... How do you like this smart use for an old bottle? Clamp an empty wine bottle to a fence or wall near your outdoor deck or ... Simple and striking, a couple of pieces of "lovingly used" furniture creates a special kind of charm. A weathered chair fo... Twine lanterns add pops of crafty—but sophisticated—flair to any outdoor setting. Wrap glue-soaked twine around a balloon ... When securely fastened to a tree or the ceiling of a porch, a pallet and some cushioning make the ideal place to lounge. V... Incorporate nature into your lighting scheme by securing a dead tree in a concrete mold and draping your pendant lamp from... For the cost of a can of exterior paint , you can totally transform your porch. Paint the floor a hue that complements yo... Repurpose birthday hats to create a string of lanterns for your porch, patio, or garden. Cut the tip of the cone, punch h... This garden shed has been decked out to the nines. Designer Orla Kiely created the intimate home for a flower trade show, ...
Newsletter_icon Google_plus Facebook Twitter Pinterest Youtube Rss_icon