Gable Vents

[mpedeferri]

I did a warranty inspection today and noticed that the attic only had gable vents and no roof jacks or ridge vent. It did have soffit vents. In the Seattle area this is the first "new construction" I ran across with no roof or ridge vents. I don't have a code book so I was wondering if anybody could help me out? Is this to code. BTW the furnace was in the attic if that makes any difference.

Thanks

Mark

[ccoombs]

This wouldn't raise a red flag in my area. But I'm in an area that is using an older code.

[John Onofrey]

Sounds okay. Upper vents are gable vents and lower vents are soffit vents. If you are concerned about not having enough upper ventilation you can always recommend the addition of passive vents.

Check the IRC for the specs. Off the top of my head it's 1 SF of ventilation for each 150 SF of attic space. This can be reduced to 1 SF of ventilation for each 300 SF of attic space if more than 50% of the ventilation is upper vents.

[David P. Valley]

In older homes, Ridge vents are not code. They are a convenience.

Gable and soffit vents work OK. Just make sure the soffit vents are not blocked with insulation.

[Russel Ray]

Soffit vents and gable vents are standard here. Some of the higher-end construction are now using a combination of gable, soffit, and static vents. The gable vents are very decorative, and the static vents are very well camouflaged as part of the roof covering. Very nice. Of course, that extra $50,000 in workmanship adds $500,000 to the cost of the house.

[mpedeferri]

Thanks for the replies everyone.

[rwand1]

Gable vents work best if they are placed parallel with prevailing winds. If winds are blowing perpindicular to the ridge you will not get any significant ventilation.

Raymond Wand
Alton, ON

[Doug Edwards]

Which is why gable vent fans are popular. I installed gables vents and a fan on an inline thermostat and dropped my cooling bill by $30 a month during the summer. Average attic temperature went from 140 degrees to about 100.

[William J. Decker]

If the furnace is in the attic and it is a cat 4, they shluld run the combustion air vent out. Expecially if the insulation is friable, like blows in cellulose or fiberglass.

[Russel Ray]

And why turbine vents are so popular. They work regardless of which way the house faces.

[David P. Valley]

Russel,

I never see Turbine Vents in Mass. (Maybe because they're ugly)

[Russel Ray]

We have designer turbine vents out here. Certainly even the older ones are no uglier than the weatherhead, electric meter, electric panel, utility poles, neighbors' trash piled up against the fence, etc. And if they do the job in helping my roof last longer, I don't really care how ugly they are perceived to be by anyone. The roof is ugly anyway, so who cares?

I'm considering changing my roof to a green roof. In a desert envrionment, and with xeriscape landscaping on the roof, I think it will work well in continuing to lower my utility bills and, of course, I won't have to worry about the roof covering wearing out and needing replacement. I'll just have to worry about dieing plants.

[Kenton H. Shepard, CMI]

Been hearing from various places that roof color is as important as ventilation. Light-colored roofs reflect a lot of solar radiation.
-Kent

[rwand1]

Longevity wise I also believe shingles are better on spaced planks, then on plywood.