lambabbey
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| 03/17/2008 1:23 AM |
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Hey folks,
I'm
going to be having a new home built later this year and am leaning toward
ICF walls and SIPs for the roof. I'll be going with 6" Logix ICFs
for the walls (11 3/4" total) and 10 1/4" SIPs for the roof. Small
house. Simple design. It's basically a long rectangle with an
attached shed extension.
I'd like some advice regarding additional insulation below the roof. The attic space in
this house will become a finished loft, the ceiling of which will
be a 12/12 SIP roof with just a layer of sheetrock beneath it. Metal
roofing on the outside. Since I won't have an additional attic above
this room to put spray foam insulation, I'm wondering if there's
anything else I should do beneath the SIP roof to provide an
additional layer of thermal protection. This loft will be a guest room,
heated with radiant heat in the floors. I'm being told that the 10 1/4" SIPs will give me an R-43
for the roof. Up here in Maine though, it would be nice to go a bit
higher in R-value, but by some means aside from simply using thicker SIPs. I have a feeling that on a small house (1,700 sq ft), these
SIPs will already look abnormally thick, even with trim and fascia
board.
I noticed in another thread that polyurethane has a better R-value. Do 8-1/4" polyurethane SIPs exist? Would they be on option worth considering? What other options should be on my radar screen?
Thanks in advance for the input,
John
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John A Gasbarre
Lamb Abbey Orchards
PO Box 623
Union, ME 04863
E-mail: orchard@lambabbey.com |
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wes
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| 03/17/2008 7:43 AM |
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John,
I have done several SIPS roof homes with 'normal' appearing overhangs.
You do not have to allow the SIPS to form the overhangs.
Your supplier should be able to provide details of non-SIPS overhangs, depending on the method of roof application you intend to use.
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Wes Shelby
Design Systems Group
Murray KY
wandr@ainweb.net |
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ReadyToRetire
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| 03/17/2008 7:55 PM |
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Wes,
What would be the advantage to shifting to framing at the wall line?
Very respectfully,
Larry
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wes
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| 03/18/2008 8:11 AM |
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In John's case, aesthetics would be the main factor. In other instances, costs can come into play. The cost of a framed overhang can be less than the cost of a SIPS overhang. Lets say you have a 40' long house with 12" overhangs, to do the roof entirely with 4' wide eave to ridge panels, would require 11 panels, with a framed overhang, only 10 panels would be required. The cost of that extra panel would be more than the cost of the framed overhang, plus I get the appearance of a conventional overhang. The eave overhangs work the same way. Now this scenario works for my markets, considering our labor costs. I can't speak for other areas, labor wise. But if are doing it yourself, or have relatively low labor rates, its worth looking at.
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Wes Shelby
Design Systems Group
Murray KY
wandr@ainweb.net |
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SteelSipMan
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| 03/18/2008 8:19 AM |
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Posted By wes on 03/18/2008 8:11 AM
In John's case, aesthetics would be the main factor. In other instances, costs can come into play. The cost of a framed overhang can be less than the cost of a SIPS overhang. Lets say you have a 40' long house with 12" overhangs, to do the roof entirely with 4' wide eave to ridge panels, would require 11 panels, with a framed overhang, only 10 panels would be required. The cost of that extra panel would be more than the cost of the framed overhang, plus I get the appearance of a conventional overhang. The eave overhangs work the same way. Now this scenario works for my markets, considering our labor costs. I can't speak for other areas, labor wise. But if are doing it yourself, or have relatively low labor rates, its worth looking at.
WRONG, you can split the panel and use half on each side of the house NO WASTE!
I see no difference in appearance between conventional and framed overhangs
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wes
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| 03/18/2008 8:29 AM |
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Hey steelhead,
40' +1'+1' = 42', you lose 2' of panel.
And if you can't see the difference between an overhang made of 2x6 subfascia and fly rafters vs a 10+" SIPS panels, then open your eyes.
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Wes Shelby
Design Systems Group
Murray KY
wandr@ainweb.net |
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lambabbey
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| 03/18/2008 2:07 PM |
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I appreciate the feedback regarding the overhangs. For me, it's more of an aesthetic thing. I'm modifying a house design where 18" SIP overhangs on the roof (the appearance of which I'm sure could be constructed a number of ways) are part of the character of the house. Here's a photo of the original house that I've modified to be about 60% larger, but the look and aesthetics of which I'm maintaining:
Original House, Gable End
Note that there are no soffits beneath the overhang. And on the gable ends, I'm not sure how else you create the overhang aside from simply allowing the SIPs to extend.
I'll be asking the builder about options and their respective costs though. I do appreciate you guys bringing this to my attention.
John |
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John A Gasbarre
Lamb Abbey Orchards
PO Box 623
Union, ME 04863
E-mail: orchard@lambabbey.com |
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SteelSipMan
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| 03/18/2008 9:03 PM |
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Posted By wes on 03/18/2008 8:29 AM
Hey steelhead,
40' +1'+1' = 42', you lose 2' of panel.
And if you can't see the difference between an overhang made of 2x6 subfascia and fly rafters vs a 10+" SIPS panels, then open your eyes.
Hey wes head;
unless you are building a mono-pitch roof it has 2 sides open you eyes and your pinhead
42 + 42 = 84 / 4 = 21
DUH!
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wes
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| 03/19/2008 7:09 AM |
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Touche.
However my methods do save 248 sf of 10+" panels and it creates an overhang that blends into its subdivision neighborhood.
By the way, how much does your company charge for 10" panels?
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Wes Shelby
Design Systems Group
Murray KY
wandr@ainweb.net |
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ReadyToRetire
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| 03/19/2008 4:57 PM |
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Wes,
Thank you for your clear explanation. I believe that I can see the difference, but I don't know that it would bother me one way or the other -- I have to think on that.
Would it make any difference on the gutters?
Very respectfully,
Larry
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wes
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| 03/20/2008 7:41 AM |
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Larry,
The effect on the gutters would be dictated more by the finish details than by the thickness of the overhang.
I would want to use the largest gutters available on the SIPS overhangs, to balance the thickness of the panels.
But I use oversized gutters on all my projects, anyway.
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Wes Shelby
Design Systems Group
Murray KY
wandr@ainweb.net |
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ReadyToRetire
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| 03/20/2008 6:10 PM |
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Thanks, Wes.
Larry
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Andy@panelworksplus
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| 04/09/2008 11:28 AM |
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Lambabbey,
A 10inch roof panel will provide plenty of R-value. The key to the whole thing is air inflitration. that means as long as you use a reputable installer that insures that the panel joints are sealed up during install with both foam and panel mastic. you will be very comfortable in your loft. I also use a 6" wide panel seal tape on the underside of roof panels on all the joints and any roof wall connections. the panel seal tape is cheap insurance that no air vappor is getting into the joint where it can do damage. the next concern i see would be sealing the panel wall conection. when i provide roof panels and gable end walls over ICF walls i use a small SIP knee wall cut at a bevel to match the roof pitch. that way any irregularities in the concrete (and there will be) can be adjusted for at the SIP knee wall. As far as the over hang issues i would use a tail pocket type overhang. tail pockets are reccesses in the foam where a 2x6 can be slid in to provide the lumber to frame the overhangs to your liking. the last bit of addvice i would suggest would be to have a blower door test with thermal imaginig done on the home after the windows are installed and before the sheetrock is hung. this will allow you to see any leaks and fix them easily. remember you only have one shot at getting the exterior envolope sealed up tight. a little forward thought and testing will go a long way in the proformance of the final product.
thanks,
Andy
Remember build tight, ventilate right! |
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Barney Lowe
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| 04/13/2008 10:22 AM |
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looks more like a hovel
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ReadyToRetire
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| 04/13/2008 1:38 PM |
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A hovel?
My immediate reaction was Wow, That's Nice! The picture says "home."
But I'd never be allowed to build it: My wife wants 2500+ sf -- I don't know why; I'd like 1000, 1500 max. (Any odds on who wins on that one?) And my knees are begining to make a 2nd story out of bounds.
John, as you've not built yet, it's obviously not your house. Where did you get the picture and plans? (Maybe they have a nice, single story, old farts house.)
Very respectfully,
Larry
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lambabbey
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| 04/13/2008 1:44 PM |
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Larry,
Pay no attention Barney Lowe. It's some oddball also known as GeorgiaTom on here who's been following me around these forums like a scorned woman with a vendetta. Picture a redneck version of Fatal Attraction, exchange the boiling bunny for a 'possum and add a banjo soundtrack. You'll get the general idea.
Thanks for the kind words about that little house. You're correct, it's not mine. It's a cottage that was designed by an architect in Washington State named Ross Chapin. I liked many aspect of the design, but the original structure was WAY too small (992 sq ft!) for my needs. I simply used it as an inspiration in designing a place of my own (which is now around 1750 sq ft with an attached greenhouse).
If you want to know more about the original house, you'll find additional photos of it (and plans) by going HERE. Chapin does good stuff, especially if you're interested in going with a smaller yet very well designed home. His homes seem to be all about a very efficient use of space. You can also buy the plans for his homes online.
By the way, if the wife is pushing for the extra 1,000 sq ft, just tell her SHE'LL be the one climbing the 22 stairs to the attic when her bones are brittle, not you.
John |
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John A Gasbarre
Lamb Abbey Orchards
PO Box 623
Union, ME 04863
E-mail: orchard@lambabbey.com |
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ReadyToRetire
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| 04/14/2008 5:00 AM |
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John,
Thanks for the cite; I'd not recognized Chapin's name before, but I think that several of his homes might be in the "Not so Big" series, which I have read. He has some really nice plans available, and one looks like it's close to both my wife's and my desires -- I've bookmarked his page.
Very respectfully,
Larry
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lambabbey
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| 04/14/2008 1:18 PM |
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Posted By ReadyToRetire on 04/14/2008 5:00 AM
John,
Thanks for the cite; I'd not recognized Chapin's name before, but I think that several of his homes might be in the "Not so Big" series, which I have read. He has some really nice plans available, and one looks like it's close to both my wife's and my desires -- I've bookmarked his page.
Very respectfully,
Larry
Larry,
That's terrific news. He's really got some well thought out designs. I'm glad it looks like there's one that would make both you and your wife happy. And the cost for the plans is very reasonable.
Out of curiosity, which plan is it?
John
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John A Gasbarre
Lamb Abbey Orchards
PO Box 623
Union, ME 04863
E-mail: orchard@lambabbey.com |
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ReadyToRetire
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| 04/14/2008 7:22 PM |
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John,
It's the Dines Point house. Not perfect, but it could be easily tweaked. The other one that we've both liked is one of Susanka's show homes:
http://www.healthyhomeplans.com/home_plans/floorplan_detail.php?plan_id=110
Lovely, but, at 3000sf, it's a tad big. The main floor is 2155sf, so I could use the upper floor for storage and a guest room. Between the two, they bracket what would be a mutually acceptable choice. As much as I like Chapin's cottages, my wife won't consider something that small as the 1st downsizing. But we've still got several years to discuss it, maybe I'll get lucky . . .
Very respectfully,
Larry
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