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rockies
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# Posted: 13 Jun 2016 20:23
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You would think that there were drawings somewhere on the internet to show how to do this. I'm trying to figure out how to use SIP floor panels in a Post Frame foundation system.
After reading about Post Frame construction on the forum I saw the advantages of this type of foundation over a basic "pier and beam" foundation. I understand that the stresses and loads from a "post frame" building are transferred straight down to the post's footing since the post is one piece of wood from the footing up to the roof. The problem is how to detail the SIP floor panels as they intersect the posts.
I plan on using 12 1/4 inch thick SIP panels for the floor. With a regular "pier" foundation you would simply attach the beams to the tops of the piers and then lay the panels flat on top of the beams.
With a "post frame" foundation the posts run up to the height of the roof so you could either have to run the beams between the posts, on the outside of the posts or on the inside in order for them to support the panels.
The easiest method would be to attach the floor beams to the inside of the exterior posts and then rest the panel edges on top of those beams (otherwise I would have to notch the panels around each beam and I think that would weaken the panels).
Then there's the question of the stud exterior walls. If the panel edges are butted up against the insides of the posts then I will have to build a wooden "ledge" either between the posts or along the outside of the posts in order to support the walls.
Confusing enough?
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Don_P
Member
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# Posted: 13 Jun 2016 21:01
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Send an email to the SIP manufacturer, this can't be the first one. I'd like to hear the response.
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Don_P
Member
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# Posted: 14 Jun 2016 00:10
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Rockies, I would send that email, but, if you are serious about going this route you should really have the post frame design manual as well. It is over at nfba.org and this edition just came out. It is expensive for you for one house and I would also like to get my hands on it. After you are done with it would be fine. If you keep it in good enough condition for me to pass along to a young engineer when I'm done (that will get that knowledge out around here more  ), I'd be happy to buy it from you for say 75%?
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Jabberwocky
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# Posted: 22 Jun 2016 09:54 - Edited by: Jabberwocky
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Rockies, I understand your dilemma perfectly as I have spent a lot of time designing post frame houses (amateurishly as a hobby mind you).
So it sounds like you aren't pouring a slab despite the post-frame construction... It seems like you were on the right track with the idea of mounting a footer to the inside of the posts at the bottom, essentially making it the same as a doubled (inside & outside) header at the top, and then using that 'shelf' to support the outside edge of your SIP panel. In my mind, you have some flexibility on what to do with the resulting gap between the SIP floor and the exterior siding (the width of the post frame timbers) because the stud walls are not load-bearing.
I think probably what I would do, in order, is mount the inside footer, then mount a 2x?" board across the top of the two footers, thus creating a 3-sided box of the two side footers and top plate. Then I would build the stud walls and lay down the SIPs at the very last. This would make your floor-to-ceiling height a little less, as it adds another 1.5" underneath your SIPs, but for the ease of installation, I wouldn't miss the 1.5."
The end result would be that your wall studs will extend down past your thick SIPs, which would allow for even more wall insulation. It would make installing baseboard trim a little more tedious, as there wouldn't be a footer board and thus you would have to stud-hunt. If I were going this route personally, I would probably opt for a heavier grade of base trim than average so as to protect the sheetrock better in-between the studs.
One more thought though: If you are using laminated dimensional lumber as the post-frame timbers, the dimensions of your footer/header/wall widths will be different from the long side of the building to the short side. This can be problematic even without throwing in the whole fabricating a SIP floor thing. 
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Jabberwocky
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# Posted: 22 Jun 2016 10:10
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.... Another thought: Is it not possible to notch the SIPs to allow for the post-frame timbers? I guess this would depend on how the measurements of the floor area vs. the dimensions of the SIPs come out of course, but it doesn't seem like much more work to notch the SIP panel than my previous idea. They are essentially boxes made of 2x lumber and OSB right? So if a square was cut out of the edge, one could build a new corner for the SIP out of the same materials, could they not? I don't see how this would affect the structural integrity of the SIP, seeing as how they have to do the same thing for windows and doors.
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rockies
Member
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# Posted: 22 Jun 2016 20:14
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Notching the corners of the SIP panels to fit around the posts was my primary concern in case it weakened the panels. I imagine that a lot of the strength in the panel is carried by the continuous wooden edges.
I think the best solution is to put a beam support (probably a 2x12) on both the inside and outside of the posts and then notch the panel corners around the posts and run them to the outside edge of the outer beam. That way the panels will be able to support the walls running outside the posts and the notched corners themselves will still be resting on the inner beam.
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Don_P
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# Posted: 23 Jun 2016 00:24
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or...
Quoting: Don_P Send an email to the SIP manufacturer,
Here's one ESR;
http://www.extremepanel.com/Details/ESR-1882.pdf
Read 4.1
Note, that company makes a SIP PWF for gravel trench or concrete footing.
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Jabberwocky
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# Posted: 23 Jun 2016 09:04 - Edited by: Jabberwocky
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rockies
I don't think that's a bad idea either (running the two footers and spanning both with the SIP), although that's creating less usable area coverage with those expensive SIPs.
Quoting: rockies I imagine that a lot of the strength in the panel is carried by the continuous wooden edges.
I'm just not seeing a tremendous degredation of integrity with what you are proposing. If I were to notch out a 5.5"x 3" corner (approximate dimension necessary for a 3 2x6" laminated post) out of a SIP and reinforce the notch with the same 2x material that I had cut off, I don't see how this severely compromises the integrity of the panel. You are simply creating a six-sided box instead of four, and we are talking about less than 1% of the square area of the panel (assuming 8'x4'). Not to mention the fact that you will be likely toenailing/screwing the notched area to the post in addition to any supporting structure underneath, like the footers for instance.
Don_P
I read the section you speak of, and found this: "The tabulated allowable transverse load values in Table 2 are for Type S panels installed as roof and floor panels with a minimum 1 1/2-inch-wide (38mm) continuous support in contact with the
panel face at each end of panels."
But scanning down to the table, I don't understand what I'm looking at as I am not an engineer.
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Don_P
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# Posted: 23 Jun 2016 21:33
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Quoting: Jabberwocky a minimum 1 1/2-inch-wide (38mm) continuous support in contact with the panel face at each end of panels."
I'm reading that as don't notch the bearing ends of those particular panels....a 1-1/2" CONTINUOUS support at each end of the panel.
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Jabberwocky
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# Posted: 24 Jun 2016 08:30
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Don_P
Gotcha... I was interpreting that as 'making sure there was continuous support at each end, regardless of what the end is shaped like.'
But is what I'm trying to convey being understood? I'm not talking about hacking out a chuck of the SIP and thus leaving shorter boards not connecting and exposed foam insulation.. I'm talking about boxing in the notched section and creating a continuous frame for the SIP with the 2x boards. In that regard, I don't see how this would be different structurally than, say, floor joists for a second story or attic in which there is an opening for a stairwell requiring no support from underneath due to the bracing employed.
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Don_P
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# Posted: 24 Jun 2016 22:32 - Edited by: Don_P
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I'm not following but that's ok... the manufacturer provides the detail and makes the panel to suit the application. That is what all these engineered products are, they engineer them. I spend more time checking on whether they are a listed engineered product and then trying to vet the product
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Jabberwocky
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# Posted: 27 Jun 2016 11:04
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Don_P
I understand. Pictures are worth thousands of words, so here you go..
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Don_P
Member
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# Posted: 27 Jun 2016 21:14 - Edited by: Don_P
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Not really.
I had to scroll up to make sure this was the same thread...
The offer is open if you really want to try to dig to the bottom of this yourself. The easy way to answer the question is to ask the folks who engineer those products... they do it for free and they stand behind it... get the design sealed.
From here there are 3 companies I can think of within 45 minutes that will sit down with you, provide engineered plans, manufacture trusses and metal roof, source and incorporate into design pretty much anything you want and build it or let you build it. Can sips be incorporated into post frame, I can't think of why not.
These are both engineered building systems. Hang the pretty pictures on the fridge, head down to their shop and help them design one for you.
...Rockies, searches for the holy grail online... this time there is a drawing
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Jabberwocky
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# Posted: 28 Jun 2016 09:17
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Quoting: Don_P Not really. I had to scroll up to make sure this was the same thread... ...Rockies, searches for the holy grail online... this time there is a drawing
...Don_P, searches user-to-user forum for someone to put down...
I provided drawings to communicate my idea, not to say it is the best way of doing it. You really need to find a better hobby than trolling around amateur user-to-user forums looking for opportunities to insult people for seeking knowledge or trying to be helpful. If your intent is to be witty or informative, I can assure you that you're doing it wrong.
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Jabberwocky
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# Posted: 29 Jun 2016 09:49
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rockies
I apologize for responding to your thread despite not being adequately qualified (i.e. in possession of an engineering degree) to present ideas on your query.
I also apologize for placing your life and the lives of others in mortal danger should you have decided to act upon my ill-advised suggestion. No doubt the floor and the entire load-bearing structure would have buckled and collapsed under the sheer weight of my stupidity and cavalier approach.
For anyone else who intends to build a post-frame building with a SIP floor and by chance stumbles upon this thread, please note that I make no claims as to the validity of the advice or drawings presented, and one should always consult with a qualified expert before attempting any home building project. I cannot be held responsible for loss or damage to any persons or things resulting from applying the suggestions found here. 
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creeky
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# Posted: 29 Jun 2016 12:39
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Of course contacting the mfcter might be a good idea.
I have done something similar. I used joists. Put the "made by me SIPS" over the joists. Voila. Insulated floor.
But then I'm building small cabins. Not Taj Mahals. You may address me as D'Artagnan.
(cavalier: a gallant or courtly gentleman, esp. armed and on horseback)
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rockies
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# Posted: 30 Jun 2016 18:38
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Um.......I am waiting for information from the manufacturer. One of the reasons I post threads on this forum is to mention products that I have discovered that I think are interesting. Usually the product has a "twist" on something that already exists but someone took a look at it and thought "this could be better". I merely present them as "options".
The second reason I post threads is to gather information on new building techniques. Every day there are hundreds of new products and methods coming onto the market and it is up to architects, engineers, building officials and the public to figure out how they all go together.
As to post frame buildings (or "pole barns" as they were once known) I didn't really know anything about them until I saw them mentioned on this site. It seems like a simple, strong method of constructing a pier foundation. I'm now trying to figure out how to integrate it into my already designed SIP cabin plans, hence the question about laying the floor panels on top of the perimeter beams and how to "cut" the panels around the posts.
All discussion is valuable since it allows the knowledge of a great many people (who may already have experience with this topic) to be presented to people who may never have considered a post frame building or SIP panels for their construction.
That said (as I have discovered with another member of this forum), a question about your idea or method is not an attack on you. Please keep the information and opinions coming but don't make the comments personal.
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