Structural Insulated Panels (SIPS) ?

[UNCLEBUCK]

anybody out there ever build there own and have some pictures to share or able to show different ways of closing up the exterior of post and beam buildings?  frames spaced at 8 ft. and posts of 8x8 green white oak is my concern for placing sheetrock against, which is what I will be placing on the interior side of the insulated panels so the interior finishing will be a breeze later on. If I sandwich sheets of blueboard insulation between 3/4 inch chipboard and then fasten sheetrock to the interior side then fasten the panel to a wet green oak post how do I keep the sheetrock from absorbing the moisture from the post /purlin etc... and still keep it looking nice on the interior view , thank you

[etat]

Uncle Buck, If I understand you correctly you are talking about a moisture barrier.  Materials typically used for moisture barrier are either kraft paper, or visqueen. Typical vapor barriers are tar paper and house wrap.  A moisture barrier does not allow either moisture or air to penetrate.  A vapor barrier resists moisture but allows the walls to breath and are usually used on the outside of the osb or plywood.I understand different areas of the country require different placement of this moisture barrier.  I studied this some when framing my house and while I can't give you a usable answer, I can tell you a little of what I learned.  If its accurate or applies to your situation I'll leave to others that are more knowledgeable, especially about your area.  Around here the recommended moisture barrier, we have a hot and humid climate and usually fairly mild winters, regular insulation with craft paper directly behind the Sheetrock. Of course some people use wet cellulose or foam, but I'll stick to the paper part. The exterior would be covered with tarpaper, or house wrap, and all windows and doors would be flashed before installing siding if properly done. Many builders not only around here but everywhere else do not do flashing properly instead rely on caulking or the siding itself to deter water.   I did understand that in very cold windy climates codes called for heavy plastic insulation on the 'outside of the osb or plywood, and that in some very dry climates with little seasonal change in the weather 'no' vapor barrier is recommended.  Have you determined what R value is recommended for you climate, and if these panels will be sufficient,  is there any codes you have to meet, and how you will handle the wiring, switches, and plug ins.  What about headers and windows. How would it be glued together.  Would it be prone to flex or warp. While I do understand sip panels are very strong and very well insulated that's about all I know about them.  It might be that you could buy them cheaper than you could fabricate them, but again I really don't know.  

[Furby]

CK,
I know this changes with location, but you don't EVER want to use plastic on the outside of osb. You should use a vapor barrier (plastic) on the inside of the house, even over the kraft paper. On the outside you want to use house wrap or some other material that will breath.
Hawaii is one place that don't really use any vapor barriers as some houses tend to be "one board walls". ;D
I agree with your statement on the caulking, it's not the best way to go, and you'll get better results by doing it the other way.

[etat]

Hey Furby, I'll just bet that you're 100 percent right.  Thanks for clearing that up for me and everyone else on the plastic.  Think maybe I must have remembered it wrong as the plastic is definately not recommended around here.  I did find a site that had some information about sip's but not how to make them..  http://www.pbspanels.com/pansys.cfm?subtopic=FAQs§ion=panelsystem

[Jim_Rogers]

I heard a story at the last timber framing conference about some government housing constructed incorrectly out west some where, maybe on an Indian reservation, where they put the vapor barrier on both the inside and the outside and trapped all the moisture in the walls. This created a condition where mold could grow. This mold was the worse kind of mold that grows in houses. It started killing people and they only re-course was to burn these houses down, and rebuild new ones.
Be very careful with vapor barriers, do your homework and find out where and how they should be installed.
As to assembling your own sip, it is very difficult to recreate the correct environment to get the proper glue to work. This environment is necessary to make not only the glue work but to have the right amount of pressure on the panels, for the right amount of time for it to work. The wood, glue, and insulation have to be the right temperature and have dry surfaces to bond.
Without these the panels are not as strong as they should be and could cause problems once hung on the building.
As mentioned, headers or framing for windows and other such problems.

Jim Rogers

[Jim_Rogers]

UncleBuck:
If you want to assemble your own panels you could do that but you'll have to plan them correctly. Such as headers and/or framing around windows and splines at the seams from panel to panel. As well as chases for the wiring.
You need to put the walls up and the roof on and make the roof water tight. Then install the sheet rock. The way it's done is to place a 5/8" shim behind the post or on the outside of the post and attach a panel threw this shim to the timber frame. Then after the roof is done and it's water tight, have the sheet rock installed by sliding it in between the post and panel up to the shim. The posts are wrapped with plastic with the joint on the inside. Just fold the plastic over the front side or inside of the post and tape it to itself. After the sheet rock is installed, and all the mud work and painting is done, trim the plastic off at the point where the post meets the sheet rock. This will keep the posts clean and if done properly the plastic will not show.
Another method to insulating a timber frame is to build a regular 2x wall outside the frame and put the insulation in that.
But you'll also have to slide the sheet rock behind the posts using this method. So you're back to wrapping the posts with plastic and cutting it off later, again.
Another key to doing this is timing. It has been said to erect your timber frame in the fall. Enclose by what ever method you have chosen over the winter. Do the interior during the spring and summer and by the time the next winter comes around you should be done. Then put the heat on, in the house. This should give the timbers time to dry out some, especially the outer inch and will help prevent or reduce checking.
Jim Rogers

[UNCLEBUCK]

hey thanks for the feedback everyone, I guess I will staple 8 inch strips of tarpaper to the outside of all posts and anything else the sheetrock will touch, I be making homemade S.I.P"s with 3/4 chipboard inside and out then sandwiched sheets of blueboard insulation between the chipboard then I just screw on the sheetrock to the S.I.P's , not sure if I should cut rough openings before or after though . I guess it dont matter with a big sawzall . I see so many ways to close in the structure that I dont think there is a right or wrong way , thought about nailing t&g to the outside first but then it would look like overkill from the inside , I like the sheetrock look because it seems to make the timberframing really stand out and look beautiful , running the electrical might be a b*&^%$  but all I know is what I see in books and thats why I asked the forum members for actual experiences at this so would be great if ya"ll show me ways that you have closed in your structures, and many thanks again !  :P

[Furby]

No problem CK. I just didn't want anything like Jim mentioned to happen.

When I think about sips I think about the kind that are made with two sheets of osb and the foam is injected between the two sheets under pressure. The foam acts as its own glue, to a point. I have seen them with sheetrock already on them from the factory. It seems to me that if you were to make your own sips, you would really be making just insulated panels not "structual" insulated panels. That's just my two cents as I really don't know that much about them.

Also if you buy them, you can have them made in very large pieces. They will cost a little bit more to have put on with a crane(not a diy project), but you can have the whole roof done in a day. You won't need any trusses or rafters, sometimes a big plus.   :

[Jim_Rogers]

UncleBuck:

All mine have been barns and sheds, no sheet rock.

If you have Jack Sobon's book, the one with the red cover, on page 157 and 158 he shows joints in panels and how to do some wiring.
(If you don't have it, I can post the photos for you).

Jim Rogers

[UNCLEBUCK]

Thanks Jim !   I missed your post somehow and just checked and all I can say is thanks !  I like that way alot so I will do it that way , I knew I could get results by asking the forum , It makes sense now when you tell it !  Maybe its time you wrote a book ,  " Jim Rogers Backyard TimberFrame WorkShop"  yeah , yeah it has a nice ring to it !   You saved me a big disaster waiting to happen !   ;D  oh I have the book so no need to show pics for me unless someone else feels like they need your help ok,

[UNCLEBUCK]

maybe this is why the amish have outhouses and lanterns and a outdoor well , to make it easy to finish the home !  Sure wouldnt mind lookin at any photos you have Jim of how you finish and fastened exterior stuff to sheds and barns and outbuildings , siding a shop,barn , it all helps me to see other peoples ways they did things !

[BrianSimmons]

I am in the planning stages of a timber frame home. I have read about the various methods of enclosure, frame between columns, frame ouside columns and sips/stress skin panels. For prices of sips and stress skin per sqare foot, check out the 2000 numbers from : http://www.foamlaminates.com/sprice.htm#Structural%20Panel%20Pricing
and the 2003 numbers from http://www.sipsproducts.com/price/

The curtain wall panel is what is being discussed with gyp board on one side (see: http://www.winterpanel.com/panels.html ).

an article on enclosing at http://www.timberframingmagazine.com/enclosing.html

By the way, stress skin panels are basically the same design as sips except they are not certified to support weight, crushing, or 12' spans, etc.

There is an article in the Feb, 2004 issue of Timber Homes illustrated on sips. A problem I see that might exist with the panel system is heat transfer from the fasteners. There is a 3/16 diameter steel nail or screw every 6" along the perimeter of the panel. A 4x12 panel will have 64 fasteners totalling 1.77 square inches of steel. Granted these are 'hidden' by the timber but if there is an airgap between the room surface covering and the timber columns, there will be condensation on these little shafts. They are hidden and this moisture could lead to dangerous mold. I may be missing something here but that looks like a possible problem area.

Seems to me, put up a skin with exterior nailers, wire from the outside, foam insulation over the top of the nailers, exterior skin nailed through foam to nailers. This should provide a wooden thermal bridge to prevent the through conductivity of the metal fasteners. Also, there are no cranes needed and no glue to gas off.

Does this make sense?

[UNCLEBUCK]

thanks BrianSimmons, I have added these to my favorites and will study them all for a few days , looks like what I was trying to explain , good luck getting your timber frame project going !  :P