Hi Guys,
I've been reading here for a while, but this will be my first post.  My wife and I are designing the "dream home".  The project concept started over 5 years ago but got crushed by financial losses.  We've recently re-started and are updating our plans and hope to build this year and next.

4 years ago the plan was to do the basement and first floor using concrete, and stick built with blown in foam above for the second floor and attic/dormers.... 

Our architect initially thought block or poured would be much more cost effective than ICF, but in mid 2011, I'm not sure that's the case.  In fact, because we want to act as our own contractor, albeit with a consulting contractor, to save money, ICF's may be a much more attractive option for the basement and first floor walls.  We won't have to deal with furring stips and other issues.  For the second floor, I'm wondering if it's worth doing SIPS.  My wife likes to keep windows open summer and winter, so it's hard to justify from an insulation point of view, but structurally they still make sense. 

So given the open window/screen doors factor, does using ICFs for the basement and first floor, and SIPs on the second floor/attic/roof, make sense?  We'd also be using a metal roof.  I've spoken to a lot of people who have a vested interest in our decision, and they're all very nice.  I'll get estimates on the ICF part.  Also, now that I'm looking into SIPs, I'm wondering if we should be doing everything above ground in SIPs.  Would that be a large cost savings? 

The person I spoke to from Insulspan said they could provide an estimate for the entire project with all the cut outs, electrical runs, headers, and sheathing.  If they're cost competitive, that might be a nice way to KISS principle it given we want to be our own contractor.

Lastly, our architect had also thought that stucco would be cost effective on a concrete home, but I've read a lot about failures of stucco when not done with an air gap, and it seems like it's expensive.  Since it's not my wife's favorite look, would cement board type siding be a big cost bump over stucco on an ICF/SIPs/Stick built mix home?  Most of what I've read seems to indicate siding would cost less than stucco.

Thanks,
Todd
 

twerner;

As most know I am a proponent of SIPs construction, I could never figure out why most  ICF builders would build the walls well and then put an inferior wood frame roof system on top?
It always seemed to me that ICFs with a SIP roof were a great combination.

But I hate switching wall systems at floor levels, it is a week point structurally and thermally. I my opinion the wall from top of foundation to the underside of the roof should be either all iCFs or all SIPs..

Siding costs are going to vary regionally so its hard to make a blanket statement about cost, there is little difference in our area.

When Stucco is directly applied to block there are no issues, when applied over SIPs flelt or wrap as required by code and wire lath. We have installed this way successfully for decades in Florida (no air gap required)

First of all, where are you located?
I ask because if you are in a moderate climate, I can't justify the additional cost of ICFs above grade.
In my area, I find the best combo is ICF basements, and switch to SIPS for everything above grade.
Unless you are in an area where stucco is predominate, I would avoid using it. Generally, whatever is the most common in your area will be the easiest to get quality installation on, and most likely will be cost competitive.

We're in the RDU area of North Carolina, so there's quite a bit of stucco in some areas but cementboard siding is clearly the most common finish in my area. I'd read a lot here and online about moisture issues with Stucco and if we don't use block for the concrete portion, I thought it would be more expensive since we'll have to build in an air gap. Which finish is lower maintanence? Cementboard siding or stucco? Chris, Where would you make the transition from concrete to SIPs or Stud built? I don't want a SIPs basement, so would you have made the change at gound level, or a few feet above ground level? I thought that doing the change a few feet above the ground would cause a problem due to the ICF wall being a different thickness than SIPS. Thanks, Todd

twerner;  I don't like SIPs below grade either.   I would make the transition from concrete to SIPs at the foundation plate (basement ceiling line) that may be several inched to several feet depending on the terrain of your lot, I also prefer balloon framed SIPs.

Thanks Chris,

I understand now. Would there be a cost savings to changing to SIPs at the foundation or a few feet above the ground?

Also, Balloon framing means the SIPS are two stories high, right? Then you put in the interior framing with joist hangers and such? Doesn't that cause you to lose a lot of the increased structural strength you get by using SIPs since you have eliminated the top plates between the floors. With a 9' first floor and 8 or 8.5' second floor, that's a tall SIP.

Thanks,
Todd

Posted By twerner on 28 May 2011 12:22 PM
Thanks Chris,

I understand now. Would there be a cost savings to changing to SIPs at the foundation or a few feet above the ground?

Also, Balloon framing means the SIPS are two stories high, right? Then you put in the interior framing with joist hangers and such? Doesn't that cause you to lose a lot of the increased structural strength you get by using SIPs since you have eliminated the top plates between the floors. With a 9' first floor and 8 or 8.5' second floor, that's a tall SIP.

Thanks,
Todd

Todd;
 
Balloon can be 2-3 stories like this 2 story with walkout basement in Taylors, SC.  panels are 0ne piece and as high as 35ft.

Hi Chris,

I was reading this: http://www.chaleffandrogers.com/templates/sip2-ballon_wall.html, and a lot of other engineering sites.

Doesn't that link say the axial load bearing capacity of my first floor wall would be over 4000 plf with traditional SIPs construction, and that it will drop to 1850 plf with balloon construction because that would only load the outer skin? So when I go to balloon construction with 4.5" SIPs on a two story structure, how much greater is the strength than 2x6 with hurriquake nails and blown in foam? 2x6 construction would give load capacities nearly 300% greater than 2x4. That seems to put 4.5" SIPs Balloon and 2x6 16" oc on equal footing structurally. If I add in Hurriquake nails and blown in foam, the SIPs look comparable, but not necessarily better, and they'll be a lot more $, won't they?

Did I miss something?

Thanks,
Todd

Todd ;

I interpreted a little different , I beleive he is saying the one skin capacity is 1850.  All mfg.s will slightly vary, our 4" x 20ft. panels axial load tested much better than the 12 ft. high panel.

Challeff's reasons to balloon frame are some of the same reasons we like to: set walls, set roof (now job is "dried-in"), then frame 2nd floor system, then 1 st. floor system. Now cut out windows. This process allows to quickly get the "box" up and work on the other items that can be done during inclement weather

When it comes to hanging joists our preference is steel rim joist attachment to interior skin and thru screw attacment to exterior skin ( although we have relied solely on the interior skin )

If we were to use wood:   a wood rim joist/ledger board (to spread load) then joist hangers plus thru screw from outside skin to ledger board

Todd,

I don't know that the IRC, specifically we use 2009, allows for SIPs to be used in a balloon configuration. I know when we step outside the IRC we are required to use a Structural guy to stamp our plans. We certainly have a protocal for attaching a SIP home atop a ICF platform/basement, but as a contractor/builder you may have to overcome the less the willing to help building folks in your county who may not have alot of ICF or SIPs experience.

I think a tight envelope can be constructed using platform building. It also complies with the IRC. Lastly, and I hate to get yelled at by the purists, the issues of thermal bridging is grossly over rated. With the introduction of good sealants and the use of SIPs as designed you can get a great envelope using a platform design as opposed to the unrecognized balloon design.

We use stucco extensively in W. Tex. It is a wonderful product We use Tyvek and find it ample for the purposes you asked. Of course the folks in the SE have far greater water issues than we, but enough SIP homes have been built in the south, with Stucco, to have a reached a point of critical mass....

Hi Greg,

Thanks for the response. What is IRC? Google gave me institute for research in construction, but that doesn't seem like a local building code that would be in North Carolina.

We have stucco homes in NC too. I don't have a preference between siding and stucco aesthetically, so I'm hoping to figure out which will be more cost effective and lower maintanence.

Thanks,
Todd

IRC stands for International Residential Code. You should check with your building department to see which code they use. You area could, like ours, not use all provisions in the IRC and/or make some up of thier own. For instance, we don't use the fire sprinkler section and they changed the egress window size requirements.

Thanks. I'll try to contact them today.
Very helpful to know that!
Todd

Available at my library 10 minutes away.  They're NC codes, but the person I spoke to at inspections thought they were based on the IRC, so I'll try to find out if there's anything on SIPs in there.