# Ridgevents efficiency in winter???



## H.roofing (Feb 10, 2011)

Do ridgevents pose a common problem in areas where weather includes snow. Do they allow airflow when covered by snow?


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## Framer53 (Feb 23, 2008)

No.

Ridge vents are very seldom covered with snow.


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## H.roofing (Feb 10, 2011)

What about if they are covered by a foot of snow? On a 4/12 slope?


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## Coolrestoration (Feb 11, 2011)

Ok i got it thx


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## H.roofing (Feb 10, 2011)

Your welcome!! By the way I love your products and so do my clients! I look forward to future business.


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## Coolrestoration (Feb 11, 2011)

H.roofing said:


> Your welcome!! By the way I love your products and so do my clients! I look forward to future business.


Do you do roof restorations


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## enforcer (Aug 25, 2008)

Good question. If there was 2 ft of snow on the roof, wouldn't the ridge vent be covered?


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## jmiller (May 14, 2010)

Coolrestoration said:


> Ok i got it thx





H.roofing said:


> Your welcome!! By the way I love your products and so do my clients! I look forward to future business.





Coolrestoration said:


> Do you do roof restorations


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## Framer53 (Feb 23, 2008)

My thoughts also.:sad:


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## H.roofing (Feb 10, 2011)

Anyone have solid advice when to avoid using ridge vent and if covered by a foot of snow does it breath??? If sophits are open but ice is on roof, and ridge vent is covered does it function??


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## jmiller (May 14, 2010)

Does your mouth function when it's covered? :shutup:

No, there has to be a way for all that hot air to escape.


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## H.roofing (Feb 10, 2011)

If not... Then why do they recommend ridge vents as best ventilation for roof. Especially when I live in winter climate where a foot of snow is normal. When is best and worst roof to ventilate using ridge vent.
Is it intended for high slope areas?


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## dennis (Nov 17, 2004)

Without baffles, ridge vents are easily plugged by blowing snow. Heavy snow will also reduce their efficiency. 
In snowy climates it's always a good idea to install gable vents along with a ridge vent if possible.


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## Mr Latone (Jan 8, 2011)

Take both hands and scoop up a big pile of snow. Now firmly plant that pile of snow against your nose and mouth. Now gently exhale.

Is this simple example significantly different than a slow moving volume of air through a ridge vent?

A warm (relatively) attic space will melt snow directly through the sheathing. The same residual heat readily migrates to the highest elevation in the attic and begins the same process at the ridge.

There was a thread recently describing a 'tunnel' created by the exhausting ridge vent under a snow cap. That is a physical illustration of the process.

Any surface mounted vent, whether at the ridge or below the ridge, will be exposed to the possibility of a snow load.


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## davinci (Dec 26, 2007)

if for example, there is NO RIDGE VENT but there are soffits..can that actually make an attic colder if there is no convection current?


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## Roofsafe (Apr 16, 2008)

I'm trying to post a couple pics of what I have done with ridge vents on a 4/12 roof with no ridge, hopefully I can do this as I do have trouble posting pics on this forum. I may have to do this twice to get it to work, so bear with me .
The first pic is of how I modify ridge vent to work on a roof without a ridge, the second is of that roof in the winter as I was roofing the home accross the street. As you can see, there is nearly a foot of snow on the roof.
http://www.contractortalk.com/members/roofsafe-25728/albums/roofing-pics/9087-100-0630.jpg

hhttp://www.contractortalk.com/members/roofsafe-25728/albums/roofing-pics/9088-100-1509.jpg


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## dennis (Nov 17, 2004)

> Take both hands and scoop up a big pile of snow. Now firmly plant that pile of snow against your nose and mouth. Now gently exhale.
> 
> Is this simple example significantly different than a slow moving volume of air through a ridge vent?


The air from your mouth would be about 98 degrees F. 

So yes, significantly different.

The air from the attic through the ridge vent will make a "tunnel", a tunnel of ice. Like the inside of an igloo. Try getting air through ice.

In the meantime that residual heat is melting snow through the roof sheathing and causing ice dams.


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## Framer53 (Feb 23, 2008)

Dennis, without being argumentative, I suggest you read building science on this subject. it is a huge no no to have both gable and ridge vents.

Ridge vents with a foot of snow over them will work as the air that is entering the attic is moving up as hot air rises and the ridge vent will then be clear to work.

Secondly, ridge vents being at the apex of a roof will have wind to blow the snow away.

Most ridge vents will be clear in a matter of a few days.


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## sclisset (Feb 9, 2011)

*Venting*

In general vents when they are working properly will continue to exhaust warm air from the attic space and melt away what ever snow is covering them. If this is not happening quickly it may be that there is not enough intake (soffit) venting to keep the system air moving properly.

The rule of tumb is equal amounts of intake and outflow minimally with slightly higher inflow than outflow preferable.

One other thing to be aware of is that the ridge vents on different horizontal ridges if not at the same height should be seperated in the attic by a barrier. Plastic sheeting, visquene is fine. Otherwise the higher ridge will use the next closest ridge as an intake.

Lomanco is a vent company with a very helpful website and technical staff that has been very helpful for me.


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## dennis (Nov 17, 2004)

Framer, just trying to help and don't mean to be argumentative either.

I've been through "building science " and have not yet found the discussion/paper that studies or addresses not using ridge and gable vents together.
Could you, or anyone, give me a link to follow?

As for the breath-ability of ridge vents covered in snow:


















I think you can see the layer of ice that has formed on the underside of the snow pack.
Been covered a couple weeks and we haven't had a lot of snow this season.

Of course, one size don't fit all. Generally speaking.:thumbsup:


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## dennis (Nov 17, 2004)

Framer,


> I may have to modify my beliefs. I have been researching this for the last hour and am having trouble coming up with data to back up the common theme of either gable or ridge vents but not both.


Thanks for the link to JLC. The last post on that thread was from Ed the Roofer(smart guy who knows his stuff) and I've had this argument with him before. The last part of his post 
"I honestly can not say, that any of the Air Vent videos that I have seen or own, (And Paul Scelsi of Air Vent has graciously allowed me to be privy to videos that are not publicly available), has not shown any with Gable Vents added to the mixture with the smoke tests.

Personally, just in my opinion, I do tend to put more weight in the theory of "Short-Circuiting" the attic ventilation flowage from lower soffit area vents to the roof top exhaust vents when gable vents are introduced to the scenario, but I have not seen conclusive evidence to either support or denounce that theory. Although I have read continual observations from respected Home Inspectors and Contractors that do support the "Short-Circuiting" aspect, those can only be taken at face value without due consideration of knowing all of the other factors that may have been in play at the time.

So, I guess I could have just taken the easier way of making my point by stating, "It Depends".

That's pretty much the way we ended our debate. Agreeing to disagree. I'm not sure if he's changed his view one way or the other.



> By the way, don't care for your reference site.


:sad: I would really appreciate knowing what you don't like about the site. Yes, it's my site, but I can take constructive criticism.

BamBam, 

Well, as far as I know, it's the only site that agrees with me and has any evidence to back me up. :whistling :smile:

jmiller,



> If you could prove it with something besides a cigarette they may well publish it.


Maybe I can apply for some of that stimulus money for a proper study/video.:laughing:


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## ssroofpros (Jan 22, 2011)

BamBamm5144 said:


> Oh GAF Sno Country. Yes, there is no W on the end.
> 
> Never heard anyone call it C3 Snow Country.


It is Snow Country...isn't it..? Try Google.? 
Anyways...Well I'm quite new to C. T. and I'd noticed that most people abbreviate and avoid mentioning the exact Co. name/brand, or website address...
As a new user I just thought they were tryin to keep it to themselves or maybe they were just lazy...? 
As begun to participate on C. T. (ask my questions, comment on threads, etc..) I started to see my certain SM posts randomly disappear..I was told it was because I wrote ServiceMagic and other Co names in full rather than abbreviating (SM)...? Ridiculous I know..!? So to keep things from disappearing I listened to em.?
With all that being said...
If anyone has info about the C.T. "rules" & "regulations" regarding your post/comment containing any specific Company Name/Brand, or website address (eg. www.leadservicethatactuallyworks.com) Please do share


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## BamBamm5144 (Jul 12, 2008)

Dennis, not saying I disagree with you at all. It may very well be right.


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