Lacustral wrote:
The FHA minimum for roof ventilation is 1 sq foot of net free area
per 300 sq. feet of attic area -

does anyone know what's optimal for keeping the house cool in summer -
not the minimum, but the optimum amount?

It seems like more than 1 in 300 is optimal from what I've heard from
various contractors.

Rule of thumb: You can't have too many/much soffit vents.

Say the house is 60x50 = 3000 sq ft. You have a 220 ft perimeter. Assuming
the space for a vent is 8", you COULD have as much as 165 sq ft of soffit
vent. That's 1:18.

Sounds about right.