# Ventilation Concerns



## Tom R (Jun 1, 2004)

I'll be building a single story 14' X 14' 'shed-roof' addition off the back wall of a 1 1/2-story (dormered) home. Can't gable the roof because of 2nd floor windows. Roof will only be 3 in 12, with dimensional shingles, and total coverage of ice/water-shield. Can't increase pitch either. Rafters will be 2 X 8's. Ceiling will be vaulted.

What's the best way to 'ventilate' this roof??

Bottom end can be vented soffit, - - not a problem. Insulation w/baffles, - - fine. 

How about at the top, - - where the roof meets the wall??

Seems like venting up top would possible create a future water problem because of the mimimal pitch. I'd prefer to vent the bottom only in this situation, but the 'powers that be' want it vented.

Anyone run into this??


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## reveivl (May 29, 2005)

Use 2x10 rafters and cut them down at the top to 2x8 for the last 12" or so (cut a wedge off), (or nail a 2x2 on), support the edge of the ply with a ledger against the building and use low-slope (gooseneck) vents. The wedges cut out provide cross ventilation. That passed for me once. Rich.


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## Tom R (Jun 1, 2004)

reveivl said:


> Use 2x10 rafters and cut them down at the top to 2x8 for the last 12" or so (cut a wedge off), (or nail a 2x2 on), support the edge of the ply with a ledger against the building and use low-slope (gooseneck) vents. The wedges cut out provide cross ventilation. That passed for me once. Rich.


Eric,

Brilliant!! Thanks. That's the ticket. You've Reveivl'd my faith!! :cheesygri


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## reveivl (May 29, 2005)

Eric????


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## Grumpy (Oct 8, 2003)

I'd do soffit vents in combination with some one way breather vents on the shed roof... or if I am invisioning this correctly I would just cut holes in the existing roof deck where the new roof meets the old... Or is this new roof joining a wall?

If it's impossible to vent this roof into an existing vented space, then just install the one way breather vents, sometimes called bullets. Ugly but effective.


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## Tom R (Jun 1, 2004)

reveivl said:


> Eric????


Sorry Rich, - - don't know where I got that.

I guess too much skippin around the posts.

I better stick to reveivl!!

How about, - - Sorry, Thanks!! :Thumbs:


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## Tom R (Jun 1, 2004)

Grumpy said:


> I'd do soffit vents in combination with some one way breather vents on the shed roof... or if I am invisioning this correctly I would just cut holes in the existing roof deck where the new roof meets the old... Or is this new roof joining a wall?
> 
> If it's impossible to vent this roof into an existing vented space, then just install the one way breather vents, sometimes called bullets. Ugly but effective.


Yeah, Grump, - - it's a roof-meets-wall.

Not familiar with so-called 'bullets'.


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## red_cedar (Mar 30, 2005)

If you cut a continuous slot of apx. 1 -1.5 inches or so along the top where the roof meets the wall. Cut and lay a material that is the same as what one uses for the ridge vent detail, lay your roof to wall flashing over the venting piece. There are various attachment options for this. 3/ 12 pitch shouldnt be a problem. I have used this detail succesfully in various situations from the one described to the top (Ridge) of a shed roof. I prefer the cobra venting.


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## Grumpy (Oct 8, 2003)

BTW they do manufacture roof-to-wall vents very similiar to what cedar just described, I've never used 'em though.


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## Grumpy (Oct 8, 2003)

http://www.klober.co.uk/printer-friendly.php?id=95 for the flat roof vents


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## TimNJ (Sep 7, 2005)

TomR, Call Diamond M. They sell prefab metal roof to wall vents. I have bought them from them. PS. Newbie here and right in your area of NJ Tom.


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## Tom R (Jun 1, 2004)

TimNJ said:


> TomR, Call Diamond M. They sell prefab metal roof to wall vents. I have bought them from them. PS. Newbie here and right in your area of NJ Tom.


Thanks, Tim, - - yeah, maybe if I get a chance, I'll run down there Saturday morning and at least check 'em out, - - where are you located at?? In business for yourself?? What all kind of work??


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## TimNJ (Sep 7, 2005)

Tom, I am in Jacobstown right down 528. I started in the field at 17 and went into business at 25 (1983).


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## Tom R (Jun 1, 2004)

Oh OK, - - I did a big deck over that-a-way a few years back, - - 2 levels, - - 3 staircases, - - an' all that, - - I forget now, - - maybe it was Arneytown Road??, - - anyway, - - it was 'North Hanover', - - somewhere near a military graveyard.

I live right on Rt 206 in N. Bordentown, - - almost in Hamilton.

I do most of my work in Bordentown, Hamilton, Lawrenceville area.

Be talkin' to ya'!!


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