Proper Roof Ventilation Needed in my Scenario?

My husband and I just purchased our house last month. We have a pitched shingled roof built on top of a flat rubber roof. If you were to go in our attic, the floor of our attic is the old flat rubber roof.

Currently, there is no ventilation coming from the soffits. The flat roof extends to the very end of the pitched roof, covering the soffits. We do have 2 gable vents and our ridge vent that is open. There is no mold in our attic as verified by our inspector and multiple roofing companies.

My question is: Should we cut ventilation into our soffits?

The prior owner to us had lived in the house since 1996 without ventilation in the soffits - and again no mold development. The prior owner said he bought the house with the pitched roof already built and he also had debated creating ventilation in the soffits - but choose not to because there was no mold.

We have had 4 roofing companies come to check out our situation. Some say that the ventilation in the soffits is needed, while others essentially say “Don’t fix what isn’t broke”.

Does anyone know why mold hasn’t developed? Do flat roofs keep the hot air out of the attic from the living space during the winter? Is this why the roof hasn’t developed any problems with 24+ years without soffit ventilation?

I appreciate the help with my scenario.

Just from what i can see, the roof is maybe a 3/12. The gable vents can’t be far off the flat roof. Maybe 3 or 4 ft. I really dig the framer on this project. Collar tie on every rafter and and not a 2x4. Short pony wall. Looks good. With the flat roof all the way to the end, do you mean the original house had no soffit, overhang?. If there is soffit, you will have to cut through the soffit, then cut through the flat roof. That cavity from the top plate into the house is going to be insulated…you hope. Its going to be a tough job. I vote for dont mess with it. Gable vent with ridgevent on that low slope, I think you are fine. It would be easier to put a starter vent on the roof than mess with the soffit


I’d leave it alone if you don’t have a severe heat gain in the summer. Make sure any kitchen/bathroom vents are sealed in the attic and go outside. You’ve got insulation in and below the mod-bit roof system, plus the mod-bit is an awesome vapor barrier. If you open the soffits you will introduce moisture into the attic. The roofers that want to vent the soffits either need work, or really don’t understand the purpose of ventilation. Can’t really blame them though, big money in venting systems and any salesman will lie to move product.