Ridge vent with turtle vents


#1

I received 3 estimates today to have my roof replaced. I got conflicting information from the 3 roofers and could use some help with questions I have.

  1. One roofer suggested I have a ridge vent installed (about 44 feet). He was going to also replace my 6 turtle vents with larger turtle vents. He said having both a ridge vent and turtle vents would increase ventilation. A different roofer told me that if I go with a ridge vent that I need to have the turtle vents removed and covered up. He said if I didn’t cover up the turtle vents, they would act as intake vents instead of exhaust vents and I wouldn’t get proper ventilation. Who’s correct?

  2. One roofer told me that he would install new felt on top of the old felt using 15 lb. on the 4/12 area and 30 lb. on the 8/12 area. He said removing the old felt was not necessary. The other roofer told me he would remove the old felt and replace with 30 lb. felt on the entire roof. Which is better?

  3. One roofer is using 30 Year Owens Corning. The other is using 30 Year GAF/Elk. Is there an opinion on what is better?

Thanks,

Albert


#2

[quote=“aburleigh”]I received 3 estimates today to have my roof replaced. I got conflicting information from the 3 roofers and could use some help with questions I have.

  1. One roofer suggested I have a ridge vent installed (about 44 feet). He was going to also replace my 6 turtle vents with larger turtle vents. He said having both a ridge vent and turtle vents would increase ventilation. A different roofer told me that if I go with a ridge vent that I need to have the turtle vents removed and covered up. He said if I didn’t cover up the turtle vents, they would act as intake vents instead of exhaust vents and I wouldn’t get proper ventilation. Who’s correct?

  2. One roofer told me that he would install new felt on top of the old felt using 15 lb. on the 4/12 area and 30 lb. on the 8/12 area. He said removing the old felt was not necessary. The other roofer told me he would remove the old felt and replace with 30 lb. felt on the entire roof. Which is better?

  3. One roofer is using 30 Year Owens Corning. The other is using 30 Year GAF/Elk. Is there an opinion on what is better?

Thanks,

Albert[/quote]

If the same contractor is the one that I bolded, then he is doing the better job with the better materials.

How can the deck sheathing be inspected if the old felt paper is not removed? He is just being lazy I think.

The removal of the mushroom vents would be required so as to not short-circuit the attic ventilation flowage.

Ed


#3

The roofer who told you to cover the turtle vents and install ridgevent is correct as turtle vents would “short circut” the airflow from the intake at the bottom of the roof. ALL of the old felt needs to be torn off, not doing so is just plain lazy and may mask defects in the decking. The only purpose of felt is to keep the roof surface dry until the shingles are installed, #15 lb and #30 lb makes no difference in keeping the deck dry once the shingles are installed. In fact i have seen #30 lb felt “telegraph” wrinkles under some shingle applications. I always use Roofers Select, a fiberglass reinforced #15 lb felt.


#4

Thanks for the reply Ed. Strangely enough, the contractor who is replacing the felt and using GAF is also the one who said to use a ridge vent with the turtle vents. He seemed the most knowledgeable at the time, but I’m now concerned that he doesn’t understand proper ventilation.

In your opinion, what is the best option for exhaust vents? I have 6 turtle vents now. Should I let him replace these with larger vents or have them covered up and add the ridge vent? The other option would be to go without the ridge vent and replace 3 of the turtle vents with turbines.

Thanks again for your help.


#5

If you go with a ridge vent, which I prefer, then you would want to remove the box-vents. The ridge works with your soffit vents to create a flow of air thru the attic. As the hot air naturally rises up and out of the ridge vent, it “sucks” fresh air in from the soffit vents. There needs to be a balance between these two in order to have proper ventilation.

As far as removing the felt, you DEFINITELY want to. When my company tears off a roof, we take it down to the decking because we want to see the condition of the wood underneath.

I personally pefer GAF/ELK but OC is a great product also.

Good Luck


#6

[quote=“aburleigh”] Strangely enough, the contractor who is replacing the felt and using GAF is also the one who said to use a ridge vent with the turtle vents. He seemed the most knowledgeable at the time, but I’m now concerned that he doesn’t understand proper ventilation.
[/quote]

:smiley:

aburleigh,

In my opinion, this contractor does understand proper ventilation.
Here is a link that explains the
Short Circuit Myth

And if someone can show me a valid study or theory that contradicts my take on the “short circuit” myth, other than a link to a company sales pitch selling ridge vents, I would be happy to check it out.

:smiley:


#7

[quote=“aburleigh”]Thanks for the reply Ed. Strangely enough, the contractor who is replacing the felt and using GAF is also the one who said to use a ridge vent with the turtle vents. He seemed the most knowledgeable at the time, **but I’m now concerned that he doesn’t understand proper ventilation. **

In your opinion, what is the best option for exhaust vents? I have 6 turtle vents now. Should I let him replace these with larger vents or have them covered up and add the ridge vent? The other option would be to go without the ridge vent and replace 3 of the turtle vents with turbines.

Thanks again for your help.[/quote]

Although 99% of contractors that study ventilation and manufacturers that see the results from misapplications recommend eliminating the mushroom vents and only utilizing the ridge vents, Dennis always makes a very compelling point. I think he is wrong, due to situations where snow or rain has been introduced into the attic from the short-circuited ventilation, but at least he makes a credible point to back up his beliefs.

Maybe that contractor read Dennis’s Ventilation Myths and believed it or maybe he doesn’t know any better.

Send him to the forum to get a better education.

Replace the muchroom vents with wood to close them off and use only, either the Shingle Vent II Ridge Vent made by Air Vent, or the Cobra Snow Country made by GAF.

Ed


#8

“Although 99% of contractors that study ventilation and manufacturers that see the results from misapplications recommend eliminating the mushroom vents and only utilizing the ridge vents,”

Ummmm, ya got a link to that study/report??? Or would you just be promoting…another myth? :smiley:

Anecdotal evidence supported by anecdotal evidence is still anecdotal evidence. At least I got pictures. :smiley:

"Maybe that contractor read Dennis’s Ventilation Myths and believed it… "

People who read are sooooo annoying. :roll:


#9

Denis, I have given you links to various actual real world experiences from home inspectors who have photographed snow coming in from gable vents due to short-circuited air flowage, but your response was that that was not typical and none of us know the exact particulars of each of those homes.

All I know, is it can and does happen.

Let the consumers know of previous potential problems at least and let them choose, based on many peoples actual observations, not just my point of view or just your point of view.

Like I said, you make a very compelling argument to state your position, but it is not widely accepted.

Ed


#10

[quote=“ed the roofer”]Denis, I have given you links to various actual real world experiences from home inspectors who have photographed snow coming in from gable vents due to short-circuited air flowage, but your response was that that was not typical and none of us know the exact particulars of each of those homes.

All I know, is it can and does happen.

Let the consumers know of previous potential problems at least and let them choose, based on many peoples actual observations, not just my point of view or just your point of view.

Like I said, you make a very compelling argument to state your position, but it is not widely accepted.

Ed[/quote]

The bottom line is that in cold climates, if you follow the manufacturers specs you don’t have problems with rain, snow, debris infiltration.
I agree that the short circuiting effect doesn’t always show itself in extreme ways like snow in the attic.
**But when it is happening people are calling you back about it… :roll: **
you can avoid these callbacks by just doing it to spec.


#11

Or by doing a simple smoke test for yourself. That will not lie. Wish i had that video.