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Incorrect attic venting.

Overlord66

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Aug 26, 2013
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23
Location
Montana
As winter progresses and the wind hammers our house I'm beginning to think that our attic/roof venting is wrong. It seems like we have to many systems and that they are canceling each other out or a causing to much loss.

Our house has fully vented soffits with baffles, we have roof vents along the main peaks and the garage roof, a powered attic fan for the summer, and Gable vents on the house and garage peaks but only on the north side of the house.

The gables are my biggest concern. With only having them on one side when it's windy you can feel the cold air gust into the attic hit the back wall and then go somewhere. I'm guessing some of the wind pushes out the roof vents and the rest get's pushed into the house via small air leaks. On the house side there is only a small area (6') between the gable vent and the the start of the interior cathedral ceilings. So that's even worse. I can tell that when it's windy we have a harder time heating the house and in the summer it doesn't feel like the air in the attic is cycling.

Should I just cover them with foam board and secure it will some MDF? Or should I leave them?
 
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stitan06

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Dec 31, 2012
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i have all three also and was told they cancel each other out im redoing my roof this spring and im getting rid of the power fan the roof vents and the gables and just using ridge vent and soffits
 

Scott H in Wheaton

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Plainfield, suburb of Indianapolis
I have all three also and was told they cancel each other out. I'm redoing my roof this spring and I'm getting rid of the power fan the roof vents and the gables and just using ridge vent and soffits

THIS

Intake Air at the bottom, Exhaust air at the top.
Ever try to drink from a straw that has a hole in the side of it? Not much draw that way. Same with roof vents.
Ridge vent is top of the straw, soffit is the bottom of the straw. No other holes or the straw won't work.
 

stitan06

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Dec 31, 2012
Messages
154
THIS

Intake Air at the bottom, Exhaust air at the top.
Ever try to drink from a straw that has a hole in the side of it? Not much draw that way. Same with roof vents.
Ridge vent is top of the straw, soffit is the bottom of the straw. No other holes or the straw won't work.

Thats what I plan on doing so it does that

Sent from my GT-P5113 using Tapatalk
 

Scott H in Wheaton

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Plainfield, suburb of Indianapolis
So then plugging my gable vents would help my house not hurt it? Would blue board work?

Yes, anything that will block out the wind.
Plastic sheeting stapled in place,
plywood
blue foam board
whatever you've got.

I tell people this when we are adding attic insulation and notice that a roofer has done improper venting. As long as you have the other vents on top you're good to go.
 
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AMCguy

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Dec 23, 2009
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Location
Sunshine Coast, BC Canada
I redid the roof on my house to match my new shop roof. I installed full length ridge vents and blocked the gable end vents that were previously the only ventilation. The reduction in heat in the summer was very noticeable.

I can't say that the house is any warmer in the winter though.
 

Twiggss

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Jul 3, 2011
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middle
I still can't belive the people who re-did the roof on my house before I bought it. They put a ridge vent on the car-port but not the house. :bs:
 

tcianci

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Feb 7, 2009
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Walpole, Ma
Some of the stuff stated here is about half right... the OP is complaining that he notices difficulty in heating during high wind situations. That has to do with heat loss and or air infiltration into the conditioned areas. This has nothing to do with venting. The purpose of venting is to keep the air exchanged in the attic space to minimize moisture accumulation and keep the attic air temperature as close to the outside temperature.

In the summer time, you want to keep the attic as cool as possible with air exchanges so that you don't have a cloud of oven-like air over your top floor adding to the cooling load. In the winter, proper venting is important in keeping the backside of the roof sheathing cold to counter any warming effect due to heat loss from the house. This helps eliminate snow melt that re-freezes into ice damn at the eaves.

I will agree that in the summer time, the multiple venting approaches in play may make the venting less than optimal, so just using the eave and ridge vents may be best.
 

wrenchguy

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NW Indiana
Some of the stuff stated here is about half right... the OP is complaining that he notices difficulty in heating during high wind situations. That has to do with heat loss and or air infiltration into the conditioned areas. This has nothing to do with venting. The purpose of venting is to keep the air exchanged in the attic space to minimize moisture accumulation and keep the attic air temperature as close to the outside temperature.

In the summer time, you want to keep the attic as cool as possible with air exchanges so that you don't have a cloud of oven-like air over your top floor adding to the cooling load. In the winter, proper venting is important in keeping the backside of the roof sheathing cold to counter any warming effect due to heat loss from the house. This helps eliminate snow melt that re-freezes into ice damn at the eaves.

I will agree that in the summer time, the multiple venting approaches in play may make the venting less than optimal, so just using the eave and ridge vents may be best.

+1, This is the best statement made in this thread. Don't worry about straws, its a matter of max ceiling insulation and correct attic ventilation. i believe gable vents are helping the overall venting factor. ur losing more btu's from glass doors and windows and the fact its windy out.
 

Scott H in Wheaton

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Plainfield, suburb of Indianapolis
i believe gable vents are helping the overall venting factor. ur losing more btu's from glass doors and windows and the fact its windy out.

If the gable vents are supplying intake air the soffit vents will be partially stagnant. I've seen this in attics with mold on the plywood roof decking near the eaves.

True, his heat loss is compounded by doors and windows and extreme wind, but he didn't ask or say anything about insulation. He should have between R49 - R60 according to US DOE.
 

CanadaBoy

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Dec 8, 2013
Messages
37
Dealing with the same thing with inadequate baffles (one every 3 or 4 trusses) especially around the bathroom upstairs. Looking into problems now. Will let you know later i guess.
 

wrenchguy

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Sep 22, 2011
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NW Indiana
If the gable vents are supplying intake air the soffit vents will be partially stagnant. I've seen this in attics with mold on the plywood roof decking near the eaves.

True, his heat loss is compounded by doors and windows and extreme wind, but he didn't ask or say anything about insulation. He should have between R49 - R60 according to US DOE.

u might get a slow down during calm times but as soon as u get a temperature difference the flow is going to start. gable vents ain't gonna hurt.

He should be talking insulation when talking attic venting. I'd say ur mold problem down near seat cut is because with conventional roof framing practices limit the amount of "r" one can get with the rafter sitting on the t-plate. Then u need to get a draft way from that number too. I been framing roofs 4 40 year stacking the rafter to top of a boxed ceiling joist with single 2x4 plate to get 6" more "r" there, plus keeping a draft way 4 venting. This framing method also stops frosted ceiling corners in the winter. More "r" is better everywhere not just where its convenient.
 
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