I have decided to eliminate my powered roof fans (most of which don’t work anyway), and istall a ridge vent and as much venting as I can get on the bottom end (exposed raftertails, thinking about circular vents beween each tail).
I do not need new shingles at this time. How difficult is it to retrofit a ridge vent without doing a new roof? Any particular product recomendations? Any other recomendations?
Thanks,
Erik
Replies
Ill give you a partial answer.
Strong circ saw and an old blade. Maybe take the current cap shingles off. Make lines and cut down through the roof. Be Careful this type of work, like any demo work is pure caution for possible accidents.
After that part, installing the vent is on the package, and then new cap shingles.
-zen
You may not need a circ saw. When I put a ridge vent in my old house, I popped off the cap shingles, & cut the felt that was underneath (with a utility knife) & noticed that the plywood from each side didn't meet, so I installed the vent.
As zendo said, its just popping off the caps then ripping down the ridge. The cap you are using will tell you the spacing that you'll need on the ridge.
A few things though, first you need to balance the venting, you want the soffit vent and the ridge vents to work together and generate air flow. Also, you need to make sure that the rafter bay is open all the way from the soffit to the ridge, if insulation is in there then you won't be doing any venting until a path is clear.
Also, set your depth on your circ so you only cut the sheathing.
Re: Balancing the vents at the soffit.
I have exposed rafter tails. The only thing I can think of is to put 3" circular vents between each rafter.
It would not technically be "balanced" (more exhaust area than intake area), but I can not think of a way to get more intake area than the circular vents.
See http://www.dixieline.com/attic/atticvent1.html for an example of the circular vents.
Any comments?
Thanks,Erik
Just FYI, there are other options. Someone (Cobra?) makes a vent you can stick between the top of the purlin/fascia/whatever it is that fills in between the rafters and the bottom of the sheathing. Of course this would require replacing the purlins. I believe there are some other options too.
Cobra vent is a good ridge vent product. Just pop off your cap shingles (these will need to be replaced.) Then cut back the sheathing to allow for air to get past the ridge. Once this is done, unroll and secure the cobra vent, and then cut and replace the cap shingles. Took me 3 hours to do this on a 20 ft. ridge the other day.
I always disliked the cobra vent because it tended to squish and look wavy. I did like the Rollvent(Obyke or Certainteed?) as it was firmer and it came with long coil nails allowing me to shoot the ridge cap on. It took longer to clean up than install.
i haven't had that experience but thanks for the recommedation. next time, i'll give that a shot and see what i think.
mpls... the best ridge vent on the market is Shingle Vent II... has a great baffle... insect filter, low profile...
built-in end caps
google Shingle Vent II