Drip Edge Venting vs. Sheathing Venting

Hi,

My apologies in advance as this is probably a repeated topic, but when I did a search I didn’t find anything that fit my situation.

I am in the process of screening contractors for a roof system replacement as my current system is about 20 years old (and on the second layer of shingles).

The biggest question I have involves the roof/attic ventilation. My house is a one story Ranch built in the mid 1960’s. I believe that the sheathing is straight, unvented plywood as the main ventilation aspect for the attic is a small fan. There is also unvented soffit/fascia on the house.

One company I have spoken with (GAF Certified Weather Stopper Contractor) recommended venting directly through the sheathing to work in conjunction with the ridge vents (GAF Snow Country).

A second company (GAF Master Elite) is recommending Ventilated Drip Edge. The drip edge is certainly the more affordable of the two options, but, living between Washington DC and Baltimore, there is always the chance of snow, which could lead to ice damming.

My question would be - assuming proper installation, is ventilated drip edge, safe from ice damming, or would it be better to have the vents cut directly into the sheathing? As a secondary question, is either method more effective than the other?

Thanks in advance for any replies!

you did not mention your pitch or type of roofing material. soffit vents with ridge vent would be the best idea in most cases, and the lowest cost. combining ridge vent with vents in the plywood creates flow problems if the plywood vents are not along the lowest edge, but doing that would look stupid having many vents along the edge of the roof. allow air in at the bottom and out the top. do not combine ridge vents with power fans, again flow problems.

Thanks for the reply Kevin!

And sorry about not mentioning those factors. I believe the pitch is either 5/12 or 6/12. I know it isn’t a low slope, but it isn’t so steep that the roof isn’t easily walk-able. The Material would be GAF Royal Sovereign shingles.

As I was working with a third GAF Master Elite company, the rep noticed that while the soffit is unvented, there is gable venting to work along with the Attic Fan. This would change the question a little bit - With gable venting and GAF Cobra Ridge vents added, might that be considered adequate? My main concern is not voiding the Warranty (System Plus or Golden Pledge - not sure which one I am going with yet).

dciproducts.com/html/smartvent.htm

Kage has a great post with the smart vent. it would be a good idea to block the gable vents and use ridge vent with the smart vent