I have been looking at SIPs and thinking up plans for them and have come up with the following thoughts. Let me know if I am wasting my time working off of these assumptions.

1. Sips can be used without exterior siding(CFB) as well as without additional roofing(metal sips, also great for spanning ability). It seems to me that for the cheapest/fastest/easiest build you would used both of these aspects to your advantage. I havent seen many projects using two types of SIPs but it makes sense to me.

1. The space under the insulated SIP roof will be conditioned space. This is very valuable space that you are paying a premium for this over trusses. To be cost effective this space needs to be utilized. The solution I have been thinking of is a flat roof/very low pitch on the second story so all of the space can be utilized.

The problem with both of these is choosing a design that is pleasent to the eye as well as a good functional layout. Well at least it is for me....

Here is some links to give you an idea of what I am thinking.

homefront-slocum I really like this layout, I would shorten this plan a couple feet and move the laundry to an attached, non-sip, garage.

Roof design The top picture is a good representation of the roof design I was heading in.

sip and flat roof seems im not the only interested in flat roof sips. This design seems rather complicated and probably costly to build.

50$/sqft! Very amazing, Beating this price would be a tough goal. The house appears to be very energy efficient as well.

Is7corvete;

The homefront-slocum would be dificult , not that the sips would leak, but the flashing with no siding or roofing would be suspect.
We have done many "SIMPLE" straight gables and hips (NO VALLEYS)
leaving exposed with great success.

In regard to your 1st assumption (using Sips without exterior siding) a few issues come immediately to mind that would have to be addressed.  Where the Sips connect the connection would have to be carefully detailed to ensure that no moisture can penetrate them.  They would also have to be incorporated in such a way as to be somewhat esthetically appealing.  Possibly this could be done with a bat (a strip of material) over the joint and then decorative bats incorporated to create a pattern.  If the panels are going to be the final finish also the question comes up how are the windows and doors going to be flashed and trimmed out.  Where the panels are resting on the sill or the foundation how will that be detailed to shed water?  At the wall to roof connection the detailing would have to dealt with also although off the top of my head this detail might be one of the easier ones to deal with (wide eaves and lots of caulking........).  I do think it's a good idea from an economy point of view if the issues could be worked out and be practical to do either in a factory or in the field.

pace on the sides not to say that flat roofs aren't a

RIO;

how many have you done like this?

I haven't done any like this but it sounded like an interesting idea.  After rereading you post it sounds like you have.  Maybe you could explain how you deal with some of the details.  I'd love to know more about this technique.  BTW, on my first post I was addressing what the original poster had written and really wasn't thinking about your post.

I am advising against use of the exposed wall and exposed roof in a parapet situation, because the flashing details are problematic.
I would only recommend exposed panels in a straight gable, hip or flat (no side wall flash) situations.
No amount of caulking will make it water tight

Is it just the parapet that you think will cause problems?

I do like the Slocum design but would certainly simplify that to make it more economical. Its not the parapet that I liked about the design, mostly liked it because it was a two story rectangular SIP with a nice layout.

Do you think CFB can be used without siding successfully? Assuming no parapets or other intricate designs.

its trying to waterproof the parapet/roof intersection.

One of the problems I have found with CFB is that it is so fragile in handling, if you snap a corner off then what? With extended exposure to water it becomes soft and pliable

Is7corvete,

One should always protect ones primary structure with a sacrificial weathering layer. Also, metal SIPs mostly come with a white enamel finish. If this is exposed for many years it oxidizes slightly. Once this happens it gets a slight tooth to it. This roughness makes dust and mildew stick to it. The panel then will have a dingy look to it that is quite unattractive. I have yet to see an older attractive exposed metal SIP building.

Good point.

Do you think that some simple coatings are sufficient to protect the SIPs? There are plenty of options for protecting mobile home roofs and the CFB can be finished with synthetic stucco. I dont think that the limitations of synthetic stucco will make a difference.

A coating of paint can protect the metal roof panels but there will be aesthetic and maintenance issues.

all of our galvalme or galvanized panels carry a 20 year Kynar finish, any building needs proper manitenance, a good preasure washing every 2 years will keep lookin like new.
Aestheticly I don't care for the bare panel look only because it looks too industrial, but it is fully funtional
 

Some metal panels are manufactured with just a prime coat to save costs and must be covered with a coating or a cladding.
But ,the panels we supply either galvalume or G90 galv. are both coated with a Kynar 500 finish, USDA approved for food proccessing application,Citrus processing facilities, clean rooms, etc. ---- highly resistive to acidic and salt environments. Formulated to resist fading and is warranted for 20 years even near salt water, providing you wash it down once a year with freshwater.

.

Hi Guys,

Good day! I am Sam Shan from China. I can resolve the surface coating problems of SIPs. We use magnesiun oxide boards as the faces with the gloss side outside. We inject polyurethane foam into the moulds and have the facings and the rigid foam stuck together. Theoretically, the sheathings can have a life span of 40 years or more. MgO board faces have many advantages over steel or OSB sheets as the sheathings. They are fire-resistant and easy to be hand-tooled.

Sam Shan
Sino-Euro Shibo Trading
samshancn@hotmail.com

How have you determined the life expectancy?

Sam,
I have been researching MagWall SIP's, but they seem to only be available to me from Calgary, Alberta - a lot of shipping costs involved to SW Ontario.  Does your company have dealers in Ontario or even Michigan?  Thanks

Hi Tom

The life expectancy is estimated as there has been no statisitics from the test centers either in USA or in China. However, from MgO borad's application history and its production process we can conclude the life expectancy can be over 40 years.

In China, this technology was prime 30 years ago and we can still find the early boards in service now. Moreover, the board is made from magnesium oxide and magenesium chloride, along with fiberglass reinforcement mesh, nonwoven fabric, perlite and sawdust. From the composition you can see they are green products without any harmful chemicals.

The factory mixes the ingredients together into motar and pour it onto a PVC plate (mould). After the chemical interaction of Mag oxide and Mag chloride, the motar tuns into Mag cement and becomes hardened very soon. After a few days of preservation, the boards are ready to be loaded.

There are problems. The biggest one is the brine recurrence caused by Mag chloride. But the problem has been overcome by most manufacturers.

The second one is the fiberglass mesh. Concerns are that the medium alkali fiberglass mesh can not last very long. But this also proves to be unnecessary as the embedded mesh doesn't have contact with air. Even in damp conditions, the mesh doesn't lose its strength.

The last problem is its corrosive effect on steel in close contact. For this, some coatings prove to be very effective. So MgO boards are the most desirable substitute for OSB.

I don't know if my answer is satisfactory. If you have further questions, please write to me.

Dear Sir,

Sorry for the late reply. I believe the cheapest way is to import the SIPs direct from us in China.

Please let me know your dimension requirements, esp. the size, thickness, the core material and the thickness of the MgO board sheathings on both sides. Then I can give you our best offer and work out the cheapest ocean freight possible.

Please rest assured of our SIPs. Thesy are of the best quality available in China.

I look forward to your reply soon.

Best regards,

Sam Shan
Sino-Euro Shibo Trading
102-37 #128 Yongfeng Rd. Langfang City 065000
Hebei, China
Tel: 86-316-5128082
Fax: 86-316-2083499
Mobile: 86-13930676023
Blog: http://samshancn.diytrade.com/sdp/401934/4/main-2143545/0/Home.html
 samshancn@hotmail.com

I have been playing around with roof designs in sketchup.

I have attached examples of a low slope roof with superficial roof surrounding to disguise the true roof. Then another with just a flat roof with no overhangs as well as one with 2' overhangs.

Makes me wonder what the price of a superficial roof vs simply overhanging the SIPs by a couple of feet. I am sure the SIPs are more expensive per/ft but more materials are needed for fake/superficial roof.

I think the models are not bad looking. The more I think about this the more I realize that there is a reason many commercial building are built similarly.

Does the fake roof go all the way around the building?  If so, what provisions have you made to take care of the water runoff from the one way slope.  Does the water have to go between the fake roof and the slope roof to reach the ground or do you have scuppers or sloped gutters?  I am curious because I can not see the back side.  Does the fake roof follow the slope roof or does the fake roof vary in height to stay level?