Replies

1. 
   Gabe_Martel | Sep 01, 2000 02:03am | #1

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   Hi Amy,

   Not sure why you think you need more venting but if there is a buildup of heat in the attic, you could of course add a fan in the gable that is matched to the available air vents already in the attic.

   You don't want something so powerful as to suck air out of the living space below.

   If you go this route, you would want to also install a thermostat to only come on when temperature is higher than the outside daytime temp. about 20 degrees F.difference

   Gabe

1. 
   Matt_G. | Sep 01, 2000 03:05am | #2

   *Amy:Most people on this board aren't too fond of gable end vents. The consensus seems to be that most of these can allow wind driven snow and rain to enter the attic.

1. 
   Bob_Walker | Sep 01, 2000 12:48pm | #3

   *I'd go for "soffit" vents, i.e., put the vents at the top of the siding just below the roof deck (above the top plate) and then a ridge vent. It shouldn't be that tough if the existing roof is shingle: tear off the ridge cap, use a sacrificial blade to rip the deacking on either side of the ridge.IMO, there are 2 reasons to vent an attic: prevent excessive moisture and heat. How much moisture can buildup depends on whats underneath: crawl spaces, bathrooms, kitchens being the big culprits.I see a lot of attics with gable vents and lots of mold on the deck sheathing, typically north side near the eaves. (I see plenty without mold, but it seems to be luck of the draw - I wouldn't put gable vents in my house.) I rarely see houses with soffit vents with mold so long as there are vents high up and so long as the box ends aren't blocked with insulation.I don't think I've ever seen a house with mold on the roof sheathing that had soffit and ridge vents.Bob

1. 
   Amy_Sw. | Sep 01, 2000 06:14pm | #4

   *Bob, Thanks for your answer. Is there a way to do soffits with exposed rafter tails? The original construction has this detail and the addition will as well.

1. 
   Bob_Walker | Sep 02, 2000 02:16am | #5

   *There's probably lots of ways to accomplish what you want.My last house had exposed rafter tails, and the sheathing and siding was notched around them and carried up to the roof decking. I cut out the siding and sheathing between the tails, from the decking down to the top of the top plate (about 3" if I recall) and installed some continuos soffit vents on the wall itself.Bob

2. 
   Matt_G. | Sep 03, 2000 07:06pm | #6

   *Amy:What is the width of your roof overhangs? ...both at the gable end and at the eaves.

3. 
   Amy_Sw. | Sep 04, 2000 07:28pm | #7

   *Matt, Our roof overhangs are 4' on the gable end and 3' on the eaves. Does that make a difference somehow (besides the extra framing we had to do for the extended overhang!).

2. 
   Amy_Sw. | Sep 04, 2000 07:28pm | #8

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   I've searched the archives, but I guess I'm too dim to figure out how they apply to me. We have an addition to our house that is about 300 sq ft (more in attic space because of overbuild on the original house), 4.5 in 12 roof. It has 2 'turtle' vents and may have a gable vent in one end. I don't think soffit vents are an option as they would differ from original construction in an obvious way - we have exposed rafter tails. Ridge vents are also out as the roof is already on, and I don't want to mess with it. Should we have the gable vent, when it can only go in one end? Is there a way to have soffit vents that won't scream 'addition'? Is the venting enough, or should we add an attic fan? We live in UT where it is very hot in the summer and reasonably cold, definitely snowy in the winter. The living space is not conditioned, so we need all the help we can get.