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mbergm57 11-02-2008 12:13 PM

Mid Roof Smart Vent and ice dams
I have been reading everything I can about roof ventilation in your helpful posts and am very interested in the smart vents. When I brought up the mid roof smart vents to our contractor he said the local roofers he talked to said the vents dont have a big enough lip to prevent backup of ice/water if we should get an ice dam. Though I know from reading the post that a properly ventilated attic should not get an ice dam, we have an old home with balloon construction, the previous remodelings done over the years have sealed off the underhangs so they cant be vented. Multiple rooflines have been joined in the front of the house including a turret style on one side of the front door and a garage addition coming out the other side. We have deicing cables on the small roof section over the front door between the turret and the garage as well as that whole side of the garage and also where the garage meets the old house in the back. Our contractor says the only reason we don't have leaks now is that we have the ice water shield all over the front of the house. Can you comment on the potential for leaking with the Smart Vents in the shingles? Do you have any other suggestions? We also have issues with bats getting into the attic. Does the Smart Vent prevent this? Sorry for the long post.

Ed the Roofer 11-02-2008 01:54 PM

I have used the Smart Vent from DCI Products on hundreds of roofs so far and have not had one complaint about anything.

The lowest pitch I have it installed on with a mid-roof application is about a 3.5/12 pitch and that was installed last year in November. I will take photos of it this year with the snow pack on the roof to show results.

I have only used it as a mid-roof application about 12-15 times, but over 6-7 years, there have been no reported problems with that application.

Proper ventilation minimizes Ice Damming, as you seem to already know, but to reduce the amount of heat escaping into the attic in the first place, you may want to consider increasing your attic insulation R-Value.

Also, when I install it as a mid-roof application, it is stil necessary to install Ice and Water Shield and Starter Strip Shingles on top of the Smart Vent as a necessary precaution.

Where are your bats getting into your home now? I see no reason that they would be able to enter through the Smart Vent.


mbergm57 11-02-2008 03:53 PM

Mid roof smart vents and ice dams
Thank you for sharing your experiences with Smart vents and your success with them. Reading your posts is what motivated me to pursue the vents with our project. Do you think the weird roof angles with different additions coming in on the old house could be the reason the local roofers are so leery about using the SmartVents? Have some of the 12-15 mid roof installs you have done been on old and complicated rooflines and additions all diving into each other? Could there be any validity in what they are saying or in your experience is it probably a poor installation on their part? We have beefed up the insulation twice in the past 25 years but it maybe time to do it again with new and better product. Right now I don't think we have much ventilation at all--certainly no roof vent.
About the bats--they get in through any opening 1/2 inch or larger--we are always finding new areas in this old lake home.. I have put extrusion devices all over, sealed up, they still get in. Looking at the DCI site on the Smart Vent, I kinda though that the 1" cut made to vent was somewhat uncovered but it appears the SmartVent somehow seals it?? but still lets air in?. I just don't want new uncoveredopenings for bats to squeeze through. Thank you for letting me pick bounce questions off you.

Ed the Roofer 11-02-2008 04:01 PM

If you could post a few different views of your homes roof, I would be able to advise you better.

No, none were installed on multi-pitched weird angled connected roof sections, yet. I would not hesitate though, if the situation caled for it.

Do the contractors have any experience installing the Smart Vent on any previous applications?

I have found very few roofing contractors who even know about it, let alone have used it.

The 1" slot is cut into the decking 6" to 7" above the bottom 7/8" thick butt edge of the Smart Vent, so they would have to lift the shingles and nails as well as the Smart Vent to find access that way.


rlamik 05-01-2011 04:57 PM

sorry-meant to start new thread

ponderguy 10-14-2011 05:49 PM

midroof smartvent
Ed, reading your comments from a few years ago, and your experience with the midroof smartvent, I have a 1914 home where I can't get the usual soffit venting also, and could benefit from the midroof venting. My question, don't these vents get covered with snow and become ineffective while they are covered. I'm not really concerned about them leaking with proper installation, but it seems if there were an inch or two of snow, the vent would be covered and blocked.

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