ian_upton
Registered Users
Posts:12
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| 03/02/2008 10:13 AM |
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First off, I'm new to this forum. We are in the early process of planning a 2000 sf or so timberframe that will be enclosed with SIPs.
I know SIPs far outperform stick built structures. I have also noticed that the cost premium vs. 4" or 6" SIPs is not significant in the long run.
So how thick is too thick? Would 8" wall and 12" roof be too extreme?
Location is central Michigan.
Thanks,
Ian. |
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Gsfrey
Registered Users
Posts:60
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| 03/02/2008 1:37 PM |
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Talk a little bit about the other systems in the home:
1. Heating system or systems
2. Capability to employ passive
3. Temperature extremes
Stuff like this will drive your decision. Although there are those sho think that all SIP's walls should be 72" thick. I think you have got to do a little more on the systems design side before you can get a truly valuable answer.
Greg Freyermuth
915-256-7563, Cell
GregFreyermuth@elp.rr.com |
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Greg Freyermuth
915-256-7563, Phone
GregFreyermuth@elp.rr.com, E-Mail |
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cmkavala
Registered Users
Posts:804
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| 03/02/2008 1:44 PM |
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Posted By ian_upton on 03/02/2008 10:13 AM
First off, I'm new to this forum. We are in the early process of planning a 2000 sf or so timberframe that will be enclosed with SIPs.
I know SIPs far outperform stick built structures. I have also noticed that the cost premium vs. 4" or 6" SIPs is not significant in the long run.
So how thick is too thick? Would 8" wall and 12" roof be too extreme?
Location is central Michigan.
Thanks,
Ian.
Ian;
If it was my house I would use 6" walls and 12" roof
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Chris Kavala
chris@southernsips.com
1-877-321-SIPS |
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ian_upton
Registered Users
Posts:12
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| 03/02/2008 1:46 PM |
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Greg,
Thanks for the reply.
ICF foundation.
Radiant floor heat. Source undetermined, I always thought I would go geotherm, however a few posts that I read questioned the payback with a tight SIP enclosure. Depending on the final site, I have toyed with the idea of solar domestic hot water to assist / heat with as well.
There will beome type of woodburning device (stove, firebox, etc.)
I do not have a final site, so I can't say if passive solar will be feasible.
Ultimately, I want a home that will be exceptionally easy to heat / cool and save on the carbon footprint.
Ian.
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cmkavala
Registered Users
Posts:804
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| 03/02/2008 1:50 PM |
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Posted By ian_upton on 03/02/2008 1:46 PM
Greg,
ICF foundation.
There will beome type of woodburning device (stove, firebox, etc.)
Ian.
Ian;
If the basement is to be used as living area - then ICF, if not theres no reason for the additional cost
Make sure your fireplace/stove is EPA rated with an outside combustion air source
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Chris Kavala
chris@southernsips.com
1-877-321-SIPS |
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ian_upton
Registered Users
Posts:12
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| 03/02/2008 2:19 PM |
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Chris,
Thanks! The basement will eventually be living space. Out of curiosity when you say ICF is not needed, do you suggest spray foam under the first floor for insulation?
Cheers,
Ian. |
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cmkavala
Registered Users
Posts:804
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| 03/02/2008 2:22 PM |
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Posted By ian_upton on 03/02/2008 2:19 PM
Chris,
Thanks! The basement will eventually be living space. Out of curiosity when you say ICF is not needed, do you suggest spray foam under the first floor for insulation?
Cheers,
Ian.
Ian;
If it will be used for living space then I would just use the ICF foundation
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Chris Kavala
chris@southernsips.com
1-877-321-SIPS |
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Gsfrey
Registered Users
Posts:60
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| 03/02/2008 2:33 PM |
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Ian,
Few points:
1. I concur with Chris' 6 1/2" walls & 12 1/2" roofs.
2. Unless you are locked into ICF for the basement there are some SIP basement panels. I do not make them, but I know they are out there and some folks posting ont his site have used them and have had success with them.
3. Use radiant in the basement as well. It is not only price point effective but in terms of green, it rocks.
Take a look at a couple of systems:
1. Tankless hot water for the house and the radiant. Definitely check out the radiant blog on this site. It is excellent.
2. If you can implement solar, and I do not know the area so I don't know the sun exposure times, but that is also an option for both solar hot water and radiant heating.
We do not get a lot of opportunities to go to the green extreme given the relatively mild desert climate, except for when we go to the mountains of N. Mexico. But it seems to me that it would better to engineer and build all these systems into the intial work to avoid costier add-ons later.
Greg
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Greg Freyermuth
915-256-7563, Phone
GregFreyermuth@elp.rr.com, E-Mail |
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PanelCrafters
Registered Users
Posts:1323
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| 03/02/2008 4:07 PM |
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Posted By ian_upton on 03/02/2008 10:13 AM
First off, I'm new to this forum. We are in the early process of planning a 2000 sf or so timberframe that will be enclosed with SIPs.
I know SIPs far outperform stick built structures. I have also noticed that the cost premium vs. 4" or 6" SIPs is not significant in the long run.
So how thick is too thick? Would 8" wall and 12" roof be too extreme?
In your location, absolutely not. We did 2 projects last year in locations in Colorado that get very cold. The owners decided on 10.25" R-40 SIP walls. And, you are correct, the up front cost, is not that much. So, for instance for a 40' x 40' structure, 8' high walls, you are talking about 1,280 sqft of panel. The upgrade from a 6.5" R-24 panel to a 10.25" R-40 panel is probably around $1.25 per sqft, or about $1,600. With an 80° Delta T, you've slashed your Heat Loss on those walls from about 4,267 BTU/Hr to about 2,560 BTU/Hr or about 60%.
Of course, I'm a proponent of Super Insulating. And, I believe that energy prices will continue to escalate. So, a few more bucks now, will save you money in the future. And, some people prefer deep window wells. %^) |
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....jc
If you're not building with OSB SIPS(or ICF's), why are you building? |
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azbuilder
Registered Users
Posts:6
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| 03/04/2008 8:26 PM |
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Posted By PanelCrafters on 03/02/2008 4:07 PM
The owners decided on 10.25" R-40 SIP walls.
Not to hijack this thread, but isn't that a low value for a 10¼" wall thickness?
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PanelCrafters
Registered Users
Posts:1323
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| 03/05/2008 7:20 AM |
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Posted By azbuilder on 03/04/2008 8:26 PM
Not to hijack this thread, but isn't that a low value for a 10¼" wall thickness?
EPS runs about R-4 per inch. 9.25"(foam) = R-37 + the OSB. R-40 is right in the neighborhood. |
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....jc
If you're not building with OSB SIPS(or ICF's), why are you building? |
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azbuilder
Registered Users
Posts:6
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| 03/05/2008 11:22 PM |
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Posted By PanelCrafters on 03/05/2008 7:20 AM Posted By azbuilder on 03/04/2008 8:26 PM
Not to hijack this thread, but isn't that a low value for a 10¼" wall thickness?
EPS runs about R-4 per inch. 9.25"(foam) = R-37 + the OSB. R-40 is right in the neighborhood.
I asked because I have been using a 6½" panel that is R-41.
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Dick Mills
Registered Users
Posts:124
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| 03/05/2008 11:31 PM |
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Azbuilder,
Who is the manufacturer of your panel? Is it Polystyrene? The highest values I have seen for XPS (which are much higher than EPS) are in the range of 5 per inch. Polyurethane panels are much higher which could give you 41 in 6.5 inches.
Dick Mills
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azbuilder
Registered Users
Posts:6
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| 03/05/2008 11:51 PM |
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| Yes, polyurethane by KC Panels (NM). |
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lambabbey
Registered Users
Posts:71
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| 03/17/2008 1:12 AM |
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Does anyone make 8-1/2" polyurethane SIPs? I've checked many SIPs websites (including KC Panels) and the thickest polyurethane SIPs I can find is 6-1/2". I've been considering going with 10-1/2" Insulspan SIPs for the roof of a house I'm building, but I'd rather drop to 8-1/2" polyurethane if it'll give me the same R-value.
Any ideas if anyone makes these?
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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Dick Mills
Registered Users
Posts:124
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| 03/17/2008 1:17 AM |
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John,
Do you need 8.5" so that your splines will be able to span the distance? Because a 6.5" PU will otherwise provide you with the same R-Value.
Dick Mills |
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lambabbey
Registered Users
Posts:71
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| 03/17/2008 1:31 AM |
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Posted By Dick Mills on 03/17/2008 1:17 AM
John,
Do you need 8.5" so that your splines will be able to span the distance? Because a 6.5" PU will otherwise provide you with the same R-Value.
Dick Mills
Dick:
I'm just trying to super-insulate this attic loft space. I assumed, and maybe erroneously so, that all things being equal, a thicker SIP with a higher R-value would give me a little better insulation. Is this a bad assumption? This stuff is all new to me. . .
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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Dick Mills
Registered Users
Posts:124
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| 03/17/2008 1:46 AM |
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John,
Your assumption is correct. PU has a higher R-Value than EPS, so a 6.5" PU panel has an R-Value that is roughly equivalent to a 10.5" EPS panel. The PU is more expensive for the same R-Value though. Also if you are spanning a longer distance, the splines in your roof might need to be larger to support the roof load, so you might need to use the thicker panels to fit in the supporting splines.
Dick Mills |
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lambabbey
Registered Users
Posts:71
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| 03/17/2008 1:59 AM |
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Dick:
The roof going onto this new house will be as straightforward as they come: 12/12 roof over an 18' x 42' rectangle. Gable ends. 18" overhang on all four sides.
Do 8-1/4" polyurethane SIPs exist? If so, who makes them and what is their R-value?
I appreciate the feedback!
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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Dick Mills
Registered Users
Posts:124
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| 03/17/2008 2:10 AM |
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John,
So with a ridge beam in the center, you are only spanning about 12 feet, so you might be able to find 6.5" PU panels that can support the load.
And, I don't know if anyone produces an 8.25". I would think that there isn't much call for that thickness, due to the expense, but you might be able to get them made. The manufacturer might need custom tooling to produce that profile, and since there isn't much demand for the profile, they might want you to pay their tooling cost which could be a significant addition as well.
But someone else may know more about it than I do.
Dick Mills |
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