I'm still early in the learning curve and would appreciate any help with a bunch of questions .
Now for the house specifics:
Located in southeast MA, the house is a Gambrel cape which has a knee wall on the front with 2 small gable dormers and a full shed dormer across the entire back. The house is 24' x 34' for 816 sq ft of attic space. I'd like to have a minimum of 6 sq ft. of ventilation. If I split intake/exhaust vents 60/40 (I think I read somewhere that this ratio was best, but...), I would need 2 1/2 ft exhaust and 3 1/2 ft intake.
I am thinking of putting Shinglevent II (with 3' ringed nails) across the ridge. Using the manufacturer's claim of 18 sq in net per linear ft, I would need 20' of ridge venting. To feed this, I need a minimum of 504 inches net on the intake side.
The front of the house is high on a very windy bluff overlooking the water. The lower half of the roof (it's a Gambrel cape or Queen Ann), from the gutter to the top of the knee wall was insulated by the builder as an exterior wall The two small gable dormers have never had any ventilation. The house faces northeast. I'd link a picture but my camera still requires film :laughing:
I am thinking of using Air vent's Edge or Cor-a-vent's In-Vent along the lip of the roof that overhangs the kneewall. There is a piece of trim that runs the length of the house just below this overhang so aesthetically, this is a good place to put it. Since Cor-a-vent claims 10 sq in per ft so the roughly 26 ft (minus 8' for the 2 dormers) gives me 260 of my needed 504 sq in. If I run the In-vent the full 34' of the back roof (there are no soffits), I'm over my target of 504 sq in intake so I could lengthen the exhaust vent accordingly.
As far as the dormers go, I will install soffit vents and ridge vents in proper ratio as well.
Has anyone experienced weather related problems with the In-vent? I get pounded here. Overlooking the water---up high---the rain and snow is merciless.
How about Airvents Edge? Any experiences--good or bad?
Along the back of the house, the Invent would be 3' above the gutter per the manufacturer. But along the front of the house, it would be just above the trim above the kneewall---almost like a drip edge. Has anyone installed it in this sort of location? I will call the manufacturer this week but I was hoping for some reports from the field.
If I install In-vent along all of the back and front edges and then calculate that I can accommodate 24' of ridge vent---which exceeds my "required" 20 ' of vent---how do I install the ridge vent? As opposed to only running 24' of Shinglevent centered on the roof---with dummy vent extending to the gable edges---do I do the math and cut a proportionally smaller opening for the full length of the ridge? It would seem that this would decrease the likelihood of driven rain or snow if the actual opening were even smaller.
Is there some validity to splitting the intake/exhaust to a 60/40 ratio? I've also read a lot of 50/50 recommendations.
I have never seen drip edge along the gable edge of a roof but after reading here, I'm thinking I should ask for it. Any arguments one way or the other?
I read somewhere--in the wee hours--that the stains on my existing light colored roof--which is facing north---is not wear but rather algae or mildew and that I should look for new asphalt shingles with a high content of some material but I don't remember what. Does this ring a bell for anyone?
Is there a special cap-type shingle that lays flatter when covering the shinglevent? The images at the website looks a lot smoother than the capped ridge vents I've seen around here.We are leaning to old fashioned 3-tab shingles because we aren't crazy about the busy look of the architectural shingles
We have a whole house fan that is mounted horizontally on the attic floor. We will be removing 2 huge vents from the gable ends which served as exhaust vents for the fan as well as for venting the attic. Provided we occasionally wanted to still use the fan--on low speed---what effect will this have on the filter material inside the ridge and edge vents? Will it serve to backflush and clean them or bunch them up and screw things up? Any best guesses?Although it is blasphemous, I'm toying with putting in a 24" x 30" gable vent on each end of the house to accommodate any excess backpressure from the fan despite any influence it may have on the ends of the balanced ridge vent system.
Thanks for any help or insights any of you can provide.
Now for the house specifics:
Located in southeast MA, the house is a Gambrel cape which has a knee wall on the front with 2 small gable dormers and a full shed dormer across the entire back. The house is 24' x 34' for 816 sq ft of attic space. I'd like to have a minimum of 6 sq ft. of ventilation. If I split intake/exhaust vents 60/40 (I think I read somewhere that this ratio was best, but...), I would need 2 1/2 ft exhaust and 3 1/2 ft intake.
I am thinking of putting Shinglevent II (with 3' ringed nails) across the ridge. Using the manufacturer's claim of 18 sq in net per linear ft, I would need 20' of ridge venting. To feed this, I need a minimum of 504 inches net on the intake side.
The front of the house is high on a very windy bluff overlooking the water. The lower half of the roof (it's a Gambrel cape or Queen Ann), from the gutter to the top of the knee wall was insulated by the builder as an exterior wall The two small gable dormers have never had any ventilation. The house faces northeast. I'd link a picture but my camera still requires film :laughing:
I am thinking of using Air vent's Edge or Cor-a-vent's In-Vent along the lip of the roof that overhangs the kneewall. There is a piece of trim that runs the length of the house just below this overhang so aesthetically, this is a good place to put it. Since Cor-a-vent claims 10 sq in per ft so the roughly 26 ft (minus 8' for the 2 dormers) gives me 260 of my needed 504 sq in. If I run the In-vent the full 34' of the back roof (there are no soffits), I'm over my target of 504 sq in intake so I could lengthen the exhaust vent accordingly.
As far as the dormers go, I will install soffit vents and ridge vents in proper ratio as well.
Has anyone experienced weather related problems with the In-vent? I get pounded here. Overlooking the water---up high---the rain and snow is merciless.
How about Airvents Edge? Any experiences--good or bad?
Along the back of the house, the Invent would be 3' above the gutter per the manufacturer. But along the front of the house, it would be just above the trim above the kneewall---almost like a drip edge. Has anyone installed it in this sort of location? I will call the manufacturer this week but I was hoping for some reports from the field.
If I install In-vent along all of the back and front edges and then calculate that I can accommodate 24' of ridge vent---which exceeds my "required" 20 ' of vent---how do I install the ridge vent? As opposed to only running 24' of Shinglevent centered on the roof---with dummy vent extending to the gable edges---do I do the math and cut a proportionally smaller opening for the full length of the ridge? It would seem that this would decrease the likelihood of driven rain or snow if the actual opening were even smaller.
Is there some validity to splitting the intake/exhaust to a 60/40 ratio? I've also read a lot of 50/50 recommendations.
I have never seen drip edge along the gable edge of a roof but after reading here, I'm thinking I should ask for it. Any arguments one way or the other?
I read somewhere--in the wee hours--that the stains on my existing light colored roof--which is facing north---is not wear but rather algae or mildew and that I should look for new asphalt shingles with a high content of some material but I don't remember what. Does this ring a bell for anyone?
Is there a special cap-type shingle that lays flatter when covering the shinglevent? The images at the website looks a lot smoother than the capped ridge vents I've seen around here.We are leaning to old fashioned 3-tab shingles because we aren't crazy about the busy look of the architectural shingles
We have a whole house fan that is mounted horizontally on the attic floor. We will be removing 2 huge vents from the gable ends which served as exhaust vents for the fan as well as for venting the attic. Provided we occasionally wanted to still use the fan--on low speed---what effect will this have on the filter material inside the ridge and edge vents? Will it serve to backflush and clean them or bunch them up and screw things up? Any best guesses?Although it is blasphemous, I'm toying with putting in a 24" x 30" gable vent on each end of the house to accommodate any excess backpressure from the fan despite any influence it may have on the ends of the balanced ridge vent system.
Thanks for any help or insights any of you can provide.