# Low Slope Roof Ventilation



## Jim F (Mar 4, 2010)

GAF/ELK, Owens-Corning, Certainteed and other roofing materials manufacturers would probably be better choices for your search than Lowes and Home Depot.


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## LDSGJA (Jul 3, 2010)

Jim F said:


> GAF/ELK, Owens-Corning, Certainteed and other roofing materials manufacturers would probably be better choices for your search than Lowes and Home Depot.


Thanks for the suggestion. Unfortunately, their websites do not contain a lot of information about their products. 

Many of the vents at Lowes (Home Depot does not provide as much info) say the vents are for 3:12's and up.

Also, the inspector said that I only need one vent to get up to code. Is that accurate? Or will I need an intake and exhaust vent? (I believe my municipality uses ICC codes or something like that for everything except plumbing and mechanical)


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## seeyou (Dec 12, 2008)

http://www.bestmaterials.com/one-way-roof-vents-621.html

Won't solve your inlet problem, but will likely satisfy the code, and won't leak if installed properly. Will exhaust moisture if it exists in attic. 

This sounds like a case of a home inspector following chapter and verse without understanding implications.


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## LDSGJA (Jul 3, 2010)

seeyou said:


> http://www.bestmaterials.com/one-way-roof-vents-621.html
> 
> Won't solve your inlet problem, but will likely satisfy the code, and won't leak if installed properly. Will exhaust moisture if it exists in attic.
> 
> This sounds like a case of a home inspector following chapter and verse without understanding implications.


Those look really cool! In fact, I would love a solar fan of some sort, BUT, I should have been more clear.

What is the cheapest piece of junk, that will work with a 1:12 slope, that will satisfy a home inspector when I turn the house around 5-10 yrs down the line?


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## Jim F (Mar 4, 2010)

Having suffered through many such previous owner quick fixes I would not be inclined to help you with this one. Consider this: you will have to live with it for those 5-10 years. The cheap fixes you are thinking about may not last that long. It's always best to do it right the first time.


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## LDSGJA (Jul 3, 2010)

Jim F said:


> Having suffered through many such previous owner quick fixes I would not be inclined to help you with this one. Consider this: you will have to live with it for those 5-10 years. The cheap fixes you are thinking about may not last that long. It's always best to do it right the first time.


Oh thanks - that's a lot of help (Sarcastic).

I am just trying to get a basic ventilation system for my tiny attic. Its still an improvement because right now it has no ventilation at all. And I don't want to spend $250 on a solar attic fan. Nor do I want to do shotty electrical work myself, or pay someone a couple hundred bucks to do it for me.

I think I am just going to shell out $50 for the turbine vent at Lowes and hope it doesn't break in two weeks.


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## Grumpy (Dec 12, 2003)

First off you should not install shingles on a 1:12... just so we are clear on that. You need a low slope material such as a single ply membrane or modified bitumen. Shingles are not warranted below 3:12 or 2:12 depending on manufacturer.

Second, steep slope and low slope roofs are designed different. There is such a thing as a warm deck design and a cold deck design. To summarize, a warm deck is that where the roof is insulated and is very common for low slope roofing. A warm deck would NOT be ventilated. A cold deck design is where the ceiling is insulated and the roof is then ventilated. Before one can say weather or not your roof should be ventilated and how it should be ventilated would depend on the design of the roof. Is it a warm deck or cold deck?

Let's assume your inspector has a clue and let's assume the design is a cold deck, then yes we should ventilate the roof. Going back to the first statement about the roof being a low slope roof, you would not want to install any kind of steep slope ventilation. Instead you would need a product engineered to be properly installed on a low slope roof. If you like fane, you would want a curb mounted fan. truth be told these are elusive beasts, I have to go to an industrial supplier to find these, none of my roofing suppliers sell them. I often see steep slope attic fans installed and then "hacked in". They always leak. If you choose to go with some kind of passive vent, there are one way and two way breather vents that are commonly referred to as "silver bullets". You may want to look into those.


Finally listen to Jim's advice. Do it right the first time or don't even bother messing with it.


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## Jim F (Mar 4, 2010)

LDSGJA said:


> Oh thanks - that's a lot of help (Sarcastic).
> 
> I am just trying to get a basic ventilation system for my tiny attic. Its still an improvement because right now it has no ventilation at all. And I don't want to spend $250 on a solar attic fan. Nor do I want to do shotty electrical work myself, or pay someone a couple hundred bucks to do it for me.
> 
> I think I am just going to shell out $50 for the turbine vent at Lowes and hope it doesn't break in two weeks.


Specific to this topic I am currently trying to figure out when I will have the time to pop open perfectly good eave vents and shopvac out blown in insulation because some dolt previous homeowner thought it would be a good idea to board them up and blow in insulation to save on his heating bill. Glad to be of assistance even if it is not the brand you are looking for.


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