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Discussion Starter #1
Would 9 6x6 treated posts be enough to support a 22x24 cabin with loft and a 12/12 pitch roof. I plan on buying pre made footings and then setting the 6x6 on top of the footing and back filling with concrete and rest dirt or should I go a different route.
 

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Civil Engineer
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You need to compute the total load on the posts. Typically the building code will give you pounds per square foot for each level of the structure, but you did not indicate where you are, or what building code you are working to (if there even is a building code), so I can't help you determine the load. But once you do know what code you are working to, you add up the total load on the posts, based on the load of each floor plus the roof load, divide by the number of posts, and that will give you the vertical load per post.

The allowable load on a post is usually governed by buckling, but may be governed by direct compression if the post is short. You did not indicate how tall the posts are, so there is no way to determine if compression or buckling will govern the minimum post size. In any case, you determine if the post is safe (need appropriate safety factor) against buckling and direct compression, then you will know if post is OK. The footing also needs to be strong enough to support the post. This requires analysis of the strength of the footing itself, and the strength of the soil supporting the footing.
 

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Master General ReEngineer
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Would 9 6x6 treated posts be enough to support a 22x24 cabin with loft and a 12/12 pitch roof. I plan on buying pre made footings and then setting the 6x6 on top of the footing and back filling with concrete and rest dirt or should I go a different route.
Ayuh,.... As a general rule of thumb, figure a support post every 8', in every direction, in a grid pattern,....
 

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Draw up a set of plans indicating structural members and spans. Get your plans approved by your building department, and then you'll know what size, how many, and where to place your footings and posts.
 

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Discussion Starter #5
Thanks for the replies. I am not pulling permits for this project as of now. I would like to stay on course for code but don't know exactly what code is. The soil type would be sandy in northern michigan. I am running the 2x10 joist the length of 22. I am going to try to get by with running post at 11 ft to break my joist on the middle beam. Room I. Attic truss for half of the cabin and rafter the other. If I do go a post every 8 ft in a grid pattern, that seems like it should safice.
 

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your question seems simple and straightforward "Will this work?" Unfortunately for someone to answer this question they would need the following:

1. Complete set of construction drawings so all loads (point loads) could be determined and members sizes determined if they are compliant or not.
2. Soil evaluation to determine the bearing capacity of the soil
3. Knowledge and experience in structural design
4. Grade and species of lumber to be used. some grades and species of wood support more weight/loads than others
5. Building Code applicable to your area, if none a copy of ASCE-7 or Wood Frame Construction Manual would certainly aid.

of course it can be difficult to determine someone's knowledge and experience, especially on an internet forum ...... if things go badly who's to blame?

or you could simply hire a local professional engineer to perform the design and get it right to begin with. May have to spend some money but it should be designed properly and if not you certainly have someone to blame other than yourself.

Good luck!
 
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