I currently live in a 3,000 sf SIP built home in Kentucky. Next year I shall relocate to Oregon where I plan to build a smaller 1,800 sf SIP home. On home #1, after the prep work on the foundation and installation of the radient heat system was finished the SIP panels were erected in 6.5 days, which included installing all exterior doors, windows, skylights, house wrap, and 30# felt on the roof. There was zero waste; however there was, I guestimate, around 10-20% waste from the 2x4 interior framing. On the next house I have been considering ordering SIP panels for my interior walls, and extending them high enough to act as the support walls for the structural roof beams. This was done for the exterior walls on my existing house and everything was exactly as needed. Since the framing was not bid seperately I cannot estimate how much labor was involved, how much nails cost, how much lumber was needed (I ordered a lot of lumber for various things) To my mind it seems like it would be about equal with the interior wall panels, but a SIP manufacturer in Nevada said the panels would be more expensive, but I still cannot accept it. A big factor was throwing all that good wood away, plus the structural lumber was not "true". I really did not like to throw it away. Plus the panels will have the electrical races installed, the door openings will be in place, the insulation will add to sound dampening, and the rooms will aid in creating dead air spaces (when the doors are closed) reducing future energy costs. Am I missing something? Are there other expenses I am overlooking? I welcome any and all comments and suggestions. Thanks

There is a lot of waste in SIPS (window and door openings removed, any panel that isn't square such as gable ends, any panel that isn't the standard panel width, etc.) - you're paying for it, just not seeing it on your end.

All of those panels are manufactured as big rectangles and then pieces are either cut out at the factory or on the job site. Who needs a leftover 38" x 82" (exterior door cut out) SIP panel? I assume the foam in those pieces gets recycled or scraped, but their isn't much you can do with a piece of OSB that size.

I think there is less waste with metal skin polyurethane SIPs that are manufactured to length than OSB SIPs.  I agree that most OSB SIP factories will charge for the large blank and then charge again for cutting out the openings.

Thank you for mentioning using a metal skined sip for the roof. I was planning to put a metal roof over the wood OSB roof. I just did not think about the metal SIP. Your sugestion helps alot. Thanks!

I guess I knew there was a charge for the unused portion of the blank SIP's, still the cost of labor, hauling, container rental, and waste removal will help offset the cost of a blank panel; and I hope the factory is set up to recycle the waste. Thanks.

DAND; the manufacturer is correct SIPs are not cost effective for interior walls

Hi Dand.
SIPS building system extremely strong, energy efficient and cost effective. Building with SIPs will save you time, money and labor. Moreover, it is the most environmentally responsible building systems available.

I throw this out for consideration only. I have no numbers to back up this contention and I am prepared to be shot down...
I have spent the majority of my life correcting the mistakes that subs have made in construction. I have learned that any time I can farm out a job to some computer somewhere, it will save me money in the long run. Labor currently represents between half and two thirds the cost of most residential construction. All this being said I would suggest that a sips panel that could be directly stuccoed, plastered or painted may be a financially viable option for interior walls. I would specify that any cutting and shaping be done by a machine rather thasome underpaid hungover factory worker. Does anyone have any numbers or experience that suggests I am a moron?

Griz

Posted By Grizwald on 25 Jan 2013 09:03 PM
I throw this out for consideration only. I have no numbers to back up this contention and I am prepared to be shot down...
I have spent the majority of my life correcting the mistakes that subs have made in construction. I have learned that any time I can farm out a job to some computer somewhere, it will save me money in the long run. Labor currently represents between half and two thirds the cost of most residential construction. All this being said I would suggest that a sips panel that could be directly stuccoed, plastered or painted may be a financially viable option for interior walls. I would specify that any cutting and shaping be done by a machine rather thasome underpaid hungover factory worker. Does anyone have any numbers or experience that suggests I am a moron?

Griz

Griz,
I have not seen any studies on machines vs underpaid / hungover factory workers, I have seen BASF studies showing 55% reduction in labor using SIPs, however the initial cost of the SIPs will be higher than stick framing.
what I can tell you from my own personal experience is that SIPs are NOT cost effective for interior walls, because sheathing and insulation are not needed on interior partitions.
If you are using metal clad SIPs in a third world country residence or a commercial cold storage building,where drywall is not required then the wall is already finished and is cost effective

Chris,
Thanks for that information. It is more or less in line with what I am contending. If MgO, or fiber cement, or metal could be prepared in a manner that would directly accept plaster than I would think that Sips interior walls would be sneaking up on competitive. In this end of the world people have been conditioned to believe that "imperfect smooth" is an acceptable wall finish. This allows atrocious drywall jobs to be covered long enough for the perpetrators to make their get-away.
It seems that stucco wire stapled to any of the aforementioned panels would allow for that kind of finish. Just a thought.
Griz

Chris,
Thanks for that information. It is more or less in line with what I am contending. If MgO, or fiber cement, or metal could be prepared in a manner that would directly accept plaster than I would think that Sips interior walls would be sneaking up on competitive. In this end of the world people have been conditioned to believe that "imperfect smooth" is an acceptable wall finish. This allows atrocious drywall jobs to be covered long enough for the perpetrators to make their get-away.
It seems that stucco wire stapled to any of the aforementioned panels would allow for that kind of finish. Just a thought.
Griz

Griz,
Having used both Mgo and fibercement SIPs, I still contend it is a bad idea for interior partitions, because: the edges are all butt joints the paster would need to be thick and just not a skim coat.
You would not have anyway to attach wall cabinets, screws will not hold in Mgo or FC, solid walls do not allow for waterlines, sewer vent stacks, It just gets complicated for interior application.
Part of the problem with bad drywall jobs is bowed/twisted wood studs. If I was going to plaster anyway I would use steel studs lath and plaster , a lot less expensive, less complicated than sips. Using studs would also alow for future wiring access.

Chris,
Sadly I must agree you are probably correct. Perhaps some day the problems you have pointed out will be solved. Thanks for the info.
Griz

When I posted this question, I did not consider the need for vents, but the water subject should be eliminated because the water lines should not be in a SIP wall. It is recommended the water be brought up inside the wall so the strand board and insulation is not broken (it reduces stength), and that is how we did it in my first SIP house. What are your thoughts on a partial SIP interior wall system using SIPs for all the necessary structural walls ie. SIPs where the support beams are needed. When this first house went up I was happy to see all the notched out SIPs ready for the beams. I agree with Griz a computer and a lazer cutout is way better than manual labor.

We manufactured over 150 SIPS homes last year and all of them had SIPs interior walls. We recommend SIPS interior walls for many reasons including healthy house recoomendations. SIPS panels have little to no interior voids, leaving no place for insects, rodants, mold and other unwanted guest to live and multiply. We use Magnesium Oxide Board skins for our interior SIPS wall panels which has superior fire ratings to standard wall board, is waterproof and does not mold or off gass any toxins. Our interior wall panels are structural and we attach the roof panels to all of the interior walls for added structural support and bracing stability of the building. Homes with interior SIPS panels are also more efficient with heating and air conditioning and work well with split systems, eliminating unhealthy ductwork and reducing tempreture control to a room by room basis.

Innova,
Where did you build these houses?
How big were they?
Were they custom designs or production?

Thanks. Griz

Innova,
Are you based in Florida and ship mostly to other countries?

Posted By Alton on 25 Feb 2013 10:03 PM
Innova,
Are you based in Florida and ship mostly to other countries?

Alton,

Just a heads up, MgO SIPs are NOT code approved here in the USA. They have not been tested and don't have any US approvals. Nobody has brought forward a MgO SIP to have it tested here in the USA.

Hence the reason you mostly see them being installed in other countries.

Posted By Lbear on 26 Feb 2013 04:36 PM

Posted By Alton on 25 Feb 2013 10:03 PM
Innova,
Are you based in Florida and ship mostly to other countries?

Alton,

Just a heads up, MgO SIPs are NOT code approved here in the USA. They have not been tested and don't have any US approvals. Nobody has brought forward a MgO SIP to have it tested here in the USA.

Hence the reason you mostly see them being installed in other countries.

Innova is based in Miami and they ship mainly to foreign countries, and mainly low cost repetitive housing. If you are thinking of buying SIPS from this company, read the contract very very carefully. If you don't catch problems at the factory before the SIPS are shipped, you are basically stuck with them as your only recourse at that point is to put them back on the boat and send them back to Miami. If you are thinking of anything but a simple structure (ie low cost housing) think twice about working with Innova. They have a hard time visualizing anything but the simplest drawing and translating that into panels that actually fit together in the field. And when they don't fit, it will be YOUR fault for not physically checking the panels at the factory. Regarding interior walls ... SIPs are not practical for any wall with plumbing runs. And they are not cost effective for interior walls, at least not at the prices I paid for MGO Sips and certainly not if you have to pay duty on them.