Size of Soffit vents

[jcole_15]

I am a first time home buyer looking to build a Maple Street Home. One of my concerns with these home is how small their soffit vents are. The overhang of the roof is very small which allows for only 2-3 inches for the soffit vents. I was wondering if this is big enough to allow for proper attic ventilation. Should I try to get a ridge vent installed? Also will how small the overhang of the roof is would that increase the chances of water leaking into the walls of my house? Thank you!

[Ohm1]

I would check with a local building official in your area. It may be that it was fine when the house was built. Yet, if you are looking to improve, then checking with your local official will start you in the right direction.

Question: Can you install ventilation louvers on each end of your attic (front and back).

[pushkins]

What you should be looking for is 1 square inch of soffit vent for every 1 square foot of attic space. Be careful when buying the pre manufactured soffit vents they really only have a 60% ventable area.

For example a 1,500-square-foot home requires 1,500 square inches of vent area =10.4 square feet (1,500/144=10.4). 10.4 square feet/.6=17.3 square feet of vent area.

If the total soffit length of the home is 100 feet, the vent width for a continuous soffit vent would be (17.3 x 12) / 100 = 2.1 inches. Vents should be purchased on the basis of net ventilation opening.

So in this example if you were to run 2" wide soffit vents continuiously around the home you'd be adequately covered.

Nothing (in my opinion) beats a ridge vent for the exit vents.

One more thing, the ridge vent openings must be at least equal to the soffit vent opening. The soffit vents can be bigger overall, but never less than the ridge vent area.

[Ohm1]

Here's a good site: http://www.airvent.com/homeowner/products/intakeSoffit-specs.shtml