Proper ventilation for this roof?


#1

I have a 1350 sqft house with what I think is a 7/12 pitch roof, if my calculations are correct. I’m having a new roof put on with new decking, and it will be stuccoed immediately afterwards. The house has decorative gable vents. One roofer suggested adding 3 dormer vents, and other suggested adding 6 low profile dormer vents.

I’m a homeowner and not a roofing contractor, but to me it makes more sense to add some sort of intake ventilation at the eaves (maybe something like Raft-A-Vent or a strip vent like the SmartVent or In-Vent?), and either a ridge vent or something up higher towards the ridge to create a chimney effect.

Here’s a Google Photos album with some pics.

Any thoughts on the best path to achieve good ventilation? I could cover the gable vents if necessary, or just use them as intake vents and throw in a few dormer vents to help out? My climate is fairly temperate in Orange County, California (coastal Southern California).


#2

I’m assuming there is not best practice for venting such a roof? The roofing contractor that I hired told me he basically vents every roof the same (with half moon dormer vents), and didn’t seem to have an understanding of the physics involved for airflow through an attic, which is why I started doing my own research. Most of the research seems to favor ridge vents with soffit vents. Soffit vents aren’t an option for me (I think), so I’m considering other options.

For whatever reason, I see very few ridge vents in my area. I’m not sure if it’s a regional thing or what.


#3

You may be able to use a SmartVent type of vent for intake.

https://dciproducts.com/smartvent-attic-ventilation/


#4

It looks like SmartVents have a defined 6" from drip edge for their location, and I would need to locate intake vents at least 8-9" in from the drip edge, and even then I would need to find a way to get baffles in there about 60" up to the open attic space. The edges of the roof are low ceilings with no attic space, just the space between the 2x rafter and the inside ceiling, and I have insulation batts in there (but could likely be compressed with vent bats if I could find a way to run them up).

Otherwise, my intake vents need to be at the side gables or about 6-7 feet up the sides to where the attic space opens up at the rafters.If you click on my photo album it might help.


#5

Are you sheeting your roof? If you are you can lay down strapping first to create a venting path from eave to ridge.


#6

You can place the SmartVents anyplace on the roof, did you visit the website?


#8

My roof was resheeted, which is when I added the insulation to the areas that would be inaccessible from the attic in the future. I thought about adding something for a pathway for ventilation for a future vent, but didn’t have time before the roofer was sheeting. He seems very disinterested in my ventilation ideas and is planning to simply add 3 half-moon dormer vents if I don’t come up with a better plan.

@Axiom Yes, which is where I got the 6" measurement from.

It sounds like from what you are saying, 6" is the minimum clearance needed from the drip edge, not the only location it can be placed. I’ll try a Google Image search for these vents being placed higher up than the drip edge to see what they look like. Have you installed these vents above the drip edge?


#9

Yes I have installed them in various places.


#10

Very cool product. Ax, no one has been showing/pushing it in my area. We do alot of older homes with exposed rafters and no sofit where that would work great.


#11

It’s a pretty versatile product and it works pretty well in most cases, AirVent has a similar product called “The Edge”.

This stuff has been out for around 15 yrs.

I am currently working on a job that has these for wall vents, a lot of them.