Originally Posted By: rbrown1 This post was automatically imported from our archived forum.
It is amazing how many roofers do not understand the need for proper roof venting.
IMHO you can never have too many vents in the roof. A ridge vent (if installed properly) will work better than the typical dome vents.
I like the Cobra vent system it does allow for the air to move outwards more freely along the ridge.
The old style aluminum vent gave us a lot of problems up here as they were prone to get blocked by snow, which on sunny winter days melted and then turned to ice. The vent would no longer work until spring when the ice melted. At that point (in some cases) the melting ice would allow water to penetrate into the attic space.
Regardless of what type of vents are used I usually recommend to have more installed and if it is a gable roof I also suggest to have gable vents installed.
Soffit vents are another thing. I have seen more than enough times where the original soffits have been covered over with vented aluminum, yet the original wood has been left on. The homeowner has no idea that the soffits have never been working and is shocked when they find out they have been scammed.
All of the soffit areas along the eve should be vented properly and baffles should be present as well.
The soffit vents and the roof vents should balance to allow for equal and proper attic ventilation.
-- Bob Brown
President NACHI Du-Ka Chapter ON. Canada
NACHI Cell: 1-484-429-5465
Originally Posted By: rbrown1 This post was automatically imported from our archived forum.
IMO these vents have got -to -go! Even if the attic is properly sealed off from the house, I have seen where these turbine vents have pulled enough air from the attic to cause the attic to become depressed thereby literally sucking air from the house through areas such as plumbing penetrations, ceiling lights etc., where the poly vapour barrier has not been sealed effectively.
In one severe case it actually sucked blown insulation out of the attic.
The turbine vents are far from maintenance free.
However they are a great "up-charge" for roofers.
-- Bob Brown
President NACHI Du-Ka Chapter ON. Canada
NACHI Cell: 1-484-429-5465
Originally Posted By: jonofrey This post was automatically imported from our archived forum.
I think the usefullness of turbine vents may depend on what climate you are in. Down here, they’ve gone back to them and they are actually the preferred upper roof vent - even over ridge vents.
You'd have to convince me that turbine vents suck air out. I only see them moving when hot air is forced out through them. When the attic is cool, the turbine doesn't move.
Originally Posted By: phinsperger This post was automatically imported from our archived forum.
rbrown1 wrote:
Regardless of what type of vents are used I usually recommend to have more installed and if it is a gable roof I also suggest to have gable vents installed.
Robert, unless I'm reading this wrong, are you saying that you recommend more venting even when there is no apparent signs of inadequate venting? Just to be on the safe side? Kind of sounds like a waste of money to me.
I am a strong believer of proper venting of attic spaces but I do not recommend additional venting unless I have a concrete and verifiable reason for doing so.
Originally Posted By: lewens This post was automatically imported from our archived forum.
John
I was in Victoria Tx about 3 years ago, it was what felt like about 200 Degrees and the wind was howling, believe me every turbo vent in the wind was spinning to beat hell.
Originally Posted By: rcooke This post was automatically imported from our archived forum.
lewens wrote:
John
I was in Victoria Tx about 3 years ago, it was what felt like about 200 Degrees and the wind was howling, believe me every turbo vent in the wind was spinning to beat hell.
Yes but too work well and get the air out air must be able to come in . Was there soffit vents???????????
I thought it always rained in Victoria. did every time I was there. Roy C sr.
Originally Posted By: ecrofutt This post was automatically imported from our archived forum.
Yes, Turbine vents pull a lot of air and can pull it out of the house if adequate low air source (soffit) vents are not present. Don’t blame the turbine vents for working like they are supposed to. Blame the lack of adequate low air source vents.
Turbine vents sucking air out of the house are a sympton, NOT the problem. The problem is inadequate low air source vents!
Originally Posted By: rcooke This post was automatically imported from our archived forum.
ecrofutt wrote:
Yes, Turbine vents pull a lot of air and can pull it out of the house if adequate low air source (soffit) vents are not present. Don't blame the turbine vents for working like they are supposed to. Blame the lack of adequate low air source vents.
Turbine vents sucking air out of the house are a sympton, NOT the problem. The problem is inadequate low air source vents!
Again I go back to the noise problem and the failure rate and allowing snow in . More reasons to not use them in my opinion.
In a soft wind at 7:00 pm they sound like a clock at 9:00 pm they sound like a running car. At 2:00 am the sound like a jet plane . No F in Way would I have one . My opinion other might agree or disagree as to their likes . Roy C sr. and I have a hearing difficulty and can hear them .
Originally Posted By: rbrown1 This post was automatically imported from our archived forum.
phinsperger wrote:
rbrown1 wrote:
Regardless of what type of vents are used I usually recommend to have more installed and if it is a gable roof I also suggest to have gable vents installed.
Robert, unless I'm reading this wrong, are you saying that you recommend more venting even when there is no apparent signs of inadequate venting? Just to be on the safe side? Kind of sounds like a waste of money to me.
I am a strong believer of proper venting of attic spaces but I do not recommend additional venting unless I have a concrete and verifiable reason for doing so.
Paul, I will only recommend extra vents if they are required. I have very seldom seen a roof that has been vented properly up here.
Roofers like to use the dome style vents and usually install them too low and always on the rear of the home.
If there are more roof lines (as in a gable return) they very seldom install vents on the returns when the returns are small.
No upper vents, even with soffit vents, the attic will not vent properly.
Usually more vents allow the attic space to breath better and increase the life of the shingles.
Even with soffit venting, if baffles aren't installed or enough of them aren't installed the roof will not vent adequately.
-- Bob Brown
President NACHI Du-Ka Chapter ON. Canada
NACHI Cell: 1-484-429-5465
Originally Posted By: Richard newman This post was automatically imported from our archived forum.
I have built a log cabin (1600 square feet - two story) with a 12/12 metal roof that requires additional ventilation. Open concept roof - Going up during the winter time ultimately creates ice inside the roof around the eaves.
To fix this, I am going to replace the existing two piece cap with a better ventilated one piece and use cobra venting to keep the critters out along the peak. Now the question - what do I put along the bottom of the roof to improve venting ??? I can't place a physical vent as there is not enough clearance between the roof and anything sticking out will be torn off by the ice. (roof is made in this order - about 4" overall width - one inch wood plank, tar paper, 2 inch blue SM, straping, and 1' blue SM, 1 " air, and then metal screwed to strapping)
Let me know your thoughts - thanks from Canada - Haliburton Ontario