Ventilation problem

I looked at a house today that clearly has some ventilation issues. The front side has clearly deteriorated early while the back is in much better shape(but still needing to be replaced). The front side is a 5/12 porch falling into a 12/12 main roof. The back is a 4/12 shed dormer. The house is currently ventilated by gable vents and a power vent, with no soffit ventilation. There seem to be lots of these in an area where I’m getting a bunch of jobs. The main attic is completely blocked by insulation where the porch roof meets the main. I don’t believe the power vent is pulling anything from down there. In the attic above the second floor there is only about 2.5 to 3 feet of head room, so i didn’t really get a good look around. I think the best choice would be to install soffit or eave vent and put up baffles in all rafter bays and a ridge vent. Anyone have any other input? Maybe a less costly solution? Also are the eave vents that sit on the roof visible when shingles are on? I’ve never used them before.

One other factor. The homeowners have been there about 3 years. They noticed about a year ago that the power vent was seized up and no longer functioning. There’s no telling when this happened and what effect this may have had on the roof’s life. The roof is 20 years old. It could have been siezed up for 8 years.

I was just looking at DCI smart vent. Would it be appropriate to put one at the eaves of the porch and then another up above the insulation line? I guess there would be no exhaust for the air in the porch roof.

Is the porch a self contained and heated environment?



We use a lot of smart vent. You can stick it in wherever you need it.

Why not just put in a new fan?

Hi ed and lefty,
porch is open to elements below roof. It is the front porch of the house, no conditioned space inside the attic area or below.
Homeowner installed a new power vent himself already (it’s not pretty!!). My concern is whether the area below the knee wall line, which is where the insulation is blocking air flow, will get enough ventilation.

You don’t need any ventilation for the porch roof then.

Start along the eave edge and where the porch intersects the main roof, you will need to look at the mid-roof application instructions.


How visible is smart vent when installed in the middle of the roof? Aesthetics will definitely be important to these folks. If there is a small bump in the middle of the roof they won’t like it.

There will be a shadow line going across the entire roof where the porch meets the main roof.

Would they prefer prematurely burned out shingles?

They are already dealing with that.

I think it looks just fine.

I will see if I can dig up a link to where I posted those photos already on a 3/12 for the mid-roof application


Scroll down to the 3rd and 4th picture before the photo of the tape measure spanning the b-vent heat stack pipe diameter. … 07-t6.html

Then, you can click on the thumbnail photo to enlarge them to see the photo better.

It is a Free Forum that I created to post some photos, so you “Might” have to register to view the photos and wait until I get back and authorize your membership.


MOst of the time when a power vent dies its due to a lack of intake. Alot of guys do not take in account for this when installing them.

There was another house in the neighborhood that had four turbines across the back and a ridge vent that I’m sure went in with the new roof. Seems to me when those turbines spin it will pull air from the ridge vent no?

I’ve always worried about ice/water infiltration during the winter months with DCI Smartvent. We use “The Inhaler” eave vent by Ever-Flo.

SHangle yes any other ventilation product along with ridge vent will have problems.