I have a ranch built in 1953 with a hip roof on 3 sides - for some reason the side with the garage is a gable roof. The eves are 12" deep. The total area of the attic is 2500sqft.
Last year a new roof was placed along with a ridge vent running the entire length of the roof - however there aren't any soffit vents. The eves themselves are solid wood. The house has central AC and a whole house attic fan with gable vents as well.
Adding soffit vents seems like an easy-enough project for me to handle. I'm going to have blown-in fiberglass insulation placed and want to get the soffit vents and baffles in before that.
I've read many different methods to calculate how many vents are needed. So far I've consistently read you need 1 sqft of venting for every 150 sqft of attic space. So 2500 sqft/150 = 16.6 sqft of total vent needed. Believe it or not the ridge vent actually calculates out to be about 8 sq ft so I need an additional 8 sq ft of soffit vent. Each 8x16" vent is 0.89 sqft so I only need to add 8.33 sqft/0.89 sqft or NINE 8x16 soffit vents? I'm questioning this because that many placed on 3 sides would look pretty sparse??? I could easily add 20 vents if placed every 6 feet.
Looking for some guidance.....are my calcs close? Is more better? Is more worse?
The actual installation is really straight forward so the labor involved is not really an issue. Tried is yesterday - drilled a hole at each corner and cut the rest out with a sawzall - screwed vent over top.