# dormer vents or O'hagen on concrete S tile roofs



## hitch (Jun 9, 2010)

I'm in the process of installing a whole house fan and will need to install 
some additional venting on the roof to accommodate the air flow needs. I need in the area of about 7-8 additional square feet of venting.

My home has concrete S tiles on the roof- exactly the same as the last photo here: http://www.ohaginvent.com/products_concrete.asp

-and I'm debating between installing O'hagen vents or dormer vents. It appears that the o'hagen's give about .75 sq ft of venting per vent whereas the dormer will give about double that per vent at 1.5 sq ft. The o'hagens seem fairly straight forward to install. 

I'm undecided as I'm not so sure that I want to install 10 o'hagens compared to only 5 dormers. The only issue is that I can't seem to be able to find anywhere on the net instructions on how to install the dormers so am basically at square one as to how many tiles will need to be removed to be installed, and just how to go about it.

Anyone with experience or insight that could comment or point me in the right direction would be much appreciated.

thanks in advance


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## seeyou (Dec 12, 2008)

I've looked at the O'hagin's before, but never actually installed them. 

Since I'm not sure what you mean exactly by "dormer vent", it's possible some tile cutting will be involved with them. There will not be any cutting necessary with the O'Hagins.

Does your tile hang on wooden strips or is it nailed/screwed down? If it hangs, the O'Hagins would be the easiest solution. 

I'd probably go for the O'Hagins since you could distribute your inlet a little better. That said, it appears to me that it would be tough to obtain the free air space that the O'Hagins claim. But that's my somewhat uneducated opinion. Since tile is somewhat loose by nature, they may be relying on adjoining tiles to breath some. The hole in the sheathing is large enough to support their claims.


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## hitch (Jun 9, 2010)

This is a link to a few pics of dormer vents:
http://www.concordsheetmetal.com/pictures/dormer-vents/

Double the net free vent area of the ohagen per vent. Definitely does not look as incognito as the ohagen, but it will be painted to match tile.


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## gxsalas (Jun 13, 2010)

*O'Hagins*

Go with the O'Hagins, the install is much tile friendly than the dormer vents. Dormer vents are used more for esthetic design accents, they can be a costly item in comparison to the O'Hagins. You will need to remove about six tiles per-vent for proper installation of roof screen/diverter at roof deck level. Most higher end homes in Florida have them.


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## TrafficCopSmith (Dec 23, 2009)

seeyou said:


> I've looked at the O'hagin's before, but never actually installed them.
> 
> Since I'm not sure what you mean exactly by "dormer vent", it's possible some tile cutting will be involved with them. There will not be any cutting necessary with the O'Hagins.
> 
> ...


Agreed on the O'Hagins vents. They look a little nicer too, once you get the vent covers. I'm not a fan of the way the dormer vents stick out so much.


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