After reading all the previous discussion here, and elsewhere, about attic venting, I’m still clueless on my situation. New house. Main portion will be unvented attic with cathedralized Icynene application (up under roof sheathing).
BUT, then a Garage wing, under a separate gabled roof joins the main roof. Icynene will be used to isolate Garage attic space from main house. A wall will go up there, Icynened, to create a seal between the two attics. The usual dropped ceiling in the garage. Saving money by not using Icynene in the garage ceiling or walls. No entry doors directly from garage into the house–you walk through an open porch.
Here in Atlanta, GA. Garage faces due South. So, do I need any garage attic venting at all in the Garage wing?
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Greetings mtn,
This post, in response to your question, will bump the thread through the 'recent discussion' listing again which will increase it's viewing.
Perhaps it will catch someone's attention that can help you with advice.
Cheers
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Not unless you plan activity that produces moisture, like warming up the car there inside every morning, or running a kero space heater.
But venting could help th e shingles last a bit longer.
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Your garage will be cooler in the summer with venting. If the garage is un-heated it really shouldn't matter in terms of moisture. If you do heat it you may get condensate on under side of roof sheeting in very cold temperatures. (Did you say Georgia?) Shingle temperature probably is not much different vented or not. I have seen arguments both ways, but I remember some one did temperature test and the roof is so darn'd hot in the sun that under sheeting cooling makes little difference.
I'm still not sure, but there is that nasty little matter of bldg. code. I'm gonna try those Elk/now GAF Cool Series roof shingles. They meet Energy Star requirements, at least initially. That's supposed to help with energy needs, but what with the Icynene I'm really using the shingles to try to get better shingle life. So, we'll see.Thanks, all.
I say yes, it needs to be vented. You might want to start by checking your state building code though. I'll bet is says yes.
BTW - how did it ever come out as far as finding a builder for your project?
Let's see. Thanks for asking, but I can't remember at what point in the process you knew I was looking for a builder. After the last one went bankrupt on me before we actually signed a contract? Wasn't that a blessing?!Yes, I think I have the real deal now. Working things up to where we can do a fixed price contract. Did run into a little snag, previously not mentioned, with the AHJ. Can't site the house where we thought we could. So, the new builder is tromping around with his grading guy and the topo survey to resite it. Otherwise, I have to rework the design. Again.BTW, just a little observation from an outsider here. Atlanta, GA is not feeling the building slowdown as much as some places, despite lots of foreclosures. What's interesting is that the builders who're doing custom work--I mean, building on their clients' land--are doing just fine, thank you. The ones who call themselves "custom builders", and even hold that designation from the local homebuilders assn, but actually are high-end spec builders, they're going under left and right now. Even the ones with no houses sitting waiting to sell. It's real estate speculation that's done them in. One other note: my archy early on said she often uses remodelers to do custom residential builds. Really shocked me. She said they're just really attentive to detail and used to solving complex problems. Never thought about it that way. I know a lot of pros think you're either a remodeler or do new construction. But I digress....
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One other note: my archy early on said she often uses remodelers to do custom residential builds. Really shocked me. She said they're just really attentive to detail and used to solving complex problems. Never thought about it that way. I know a lot of pros think you're either a remodeler or do new construction. But I digress....
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I think she makes a few good points but... As far as I know most people go into remodeling for 2 reasons... 1) they can make more money than in new construction, and 2) remodeling is less prone to market swings. If you don't mind me saying though, I wouldn't necessarily look to an architect for a lot of budget advice... Sounds like a good way to bust the bank...
BTW I'm gonna go and look up those GAF shingles you were talking about. I'm gearing up to build 4 Energy Star Certified homes, and I've never heard of Energy Star shingles. I have a list of improvements from the certifier and shingles isn't on the list... It's hard for me to believe that shingles could effect energy consumption very much - guess I better to read the mfg's propaganda... :-)
Here's the first one I pulled up:
http://209.85.207.104/search?q=cache:IwKSglU6WG0J:www.gaf.com/Content/Documents/20269.pdf+%22GAF+Cool+Series%22&hl=en&ct=clnk&cd=2&gl=usI'm trying to get LEED certification, which requires Energy Star as a prerequisite in some of the point-certification areas. It'll be awhile before we get the build registered with LEED and find out if the shingles will be allowed.Here's how I read through the lines on it: Those shingles are Energy Star qualified (question: any special meaning to "qualified"?? Does that mean it's automatic? Or is something else required too?)Secondly, the cool roof rating council, whatever the correct name is, rates the shingles in terms of their INITIAL performance. Okay, realistically there's no other way to rate anything. So, I'm wondering how long it takes that performance to decline once the shingles start losing substantial amounts of granules. Still, I'm figuring they give me a few years of better performance. Maybe a small edge over their lifetime even.And yep, the archy designed it at 40% over budget. Said she'd help us find a builder to bring in as a consultant early on to help her design to budget. Didn't do that (too busy). By the time I got one and got his estimate--whoa!! So I paid an atty. some money to get me out of the rest of the archy's contract and get me the rights to the digital design data. Finishing up with builders and a draftsman. Should've gone that route in the first place, since I knew what design I wanted. Hindsight.
Hope you had better luck than I did on those GAF shingles. EnergyStar.gov is only showing GAF's Timberline Prestique in white. Most folks, except in FL or SW, don't want white. I don't want white; that's why I was specifying this line. Because when Elk introduced it they had it documented all over as Energy Star and they didn't even carry the "Cool Series" in white. I've got all that literature still.GAF now has in their new specs the qualifier "in certain colors". That be WHITE. I emailed GAF's tech people to see what they'll put in writing .On the energy star site I found Edco's Arrowline "shingle/shake" as Energy Star rated. Had no color qualifier. You could check that out. Metal, of course; lots of those get the star. I stopped scanning at GAF, but if you want to continue:
at energystar.gov, scroll down to Home Envelope. Select "Roof Products" In the next window, in the right side nav. bar under "For Consumers" select "Product List". In about the fourth column in that .pdf file is the Type. I held the down arrow and let it run till "shingles" came up.Good luck with it. You might find some other roofing products that are Energy Star if that would help you. Just not asphalt shingles.
Check on http://www.buildingscience.com about unvented attics and such with foam. I think where you are, that far south, you still need venting even though you're using foam. I'm up north, so I did not pay that much attention to the sections on the south. That site is excellent, lots of good info. Also, check with icynene and your local installer before you get too far along.
Just did a foamed house, including roof. Has an attached garage with unfinshed space above. Inspections required sofit, and gable end or ridge venting. Elk does warranty their shingles over unvented roofs. I can see how the white shingles would help the LEEDH rating, because even with the foam, attics still get warm... but nothing like vented<G> If dogs run free, then what must be,
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