If I went with the recommended 2"x10" without center beam, would the supported ends need to be double up, or could they be like this?

Quote from: NathanS on 3/16/2023, 8:40:17 AMThey make marine boat woodstoves that would be perfect for a little space like that.

I remember seeing someone with one of those on here a couple years ago.  It was a very attractive unit.
I was leaning more towards a small direct-vent propane heater.  They sell the 11,000 BTU units at a decent price.  They also take very little room, which helps in such a small structure.  Still haven't decided though.

Something like this:

Version 3.1.5 - 03.17.2023
- Added a fluting number parameter for classical columns.



Really wasn't wanting to dig into this right now but after a quick inspection of my code I realized it would only take me a few minutes to add in this additional parameter so that one could fine tune the look of the fluting of classical columns.

This update per customer request.

I'm not sure about the spray foam. Before I enclosed the eaves on my house, starlings would dig into and nest in the polyiso insulation. It's incredible the damage animals can do. Chipmunks actually chewed through the wood after it was enclosed and I believe they nested in it too.

I believe 18" is the separation needed to use non PT lumber.  

I just had the floor of my cabin spray foamed, we did 2".  Amazing the difference it made, highly recommend.  For a small occasionally used cabin I don't think you need any more than 2".  And I don't see how animals could get into it, but I guess I'll have to report back on that.

Quote from: NathanS on March 16, 2023, 07:40:17 AMI would consider framing the entire floor and subfloor with pressure treated. Insulate on top of the subfloor with 2"XPS. Anything underneath will turn into nest material for animals, I think.

I was contemplating that when the floor would have been much closer to the ground (had I left the beams lay directly on the foundation screws).  Since moving it up, I should have 18-20 inches above ground, and I seem to remember one of the Don's mentioning that was a safe zone for non-treated.   The only insulation I plan on adding is spray foam, I wonder, could that be used as nest material?  I was also concerned having pressure treated on the floor (off-gassing), since insulation will only happen in 1-2 years, and I will be using it in the meantime. 

Blocks are also difficult for me as I have a bad back, after my last surgery my doctor advised against any heavy lifting.  I tend to work like a madman for 16 hours straight, then have to lie on a sofa for 2 weeks to recover.  That was also driving the foundation screw idea.

All the weight (not a whole lot of it) goes to the to eave walls. At 12' your floor doesn't need a center support just some 2x10s or 2x12s, all 3 of the center screws aren't necessary - as long as you're doing joists and rafters.

They make marine boat woodstoves that would be perfect for a little space like that.

Just my opinion, you could lay down some solid CMU blocks and frame right on those. If the building moves its light enough to jack up with a car jack and shim.

I would consider framing the entire floor and subfloor with pressure treated. Insulate on top of the subfloor with 2"XPS. Anything underneath will turn into nest material for animals, I think.

I slept on it, and realized you probably mean just the center beam can changed, keeping all outer beams the same.  That would mean 8 foundation screws instead of 9, and only the center beam can have a larger size.  In reality, the perimeter is where all the weight should be, and the center screw will only really deal with floor bounciness...  I will do some more drawings today, thanks for the suggestion,

Quote from: 1akbig1bear on July 22, 2019, 11:45:09 PMWell we made our 2019 trip and hope you all enjoy the new photos
https://imgur.com/gallery/K3yyF5X word hurdle
Copy and paste and hope you like them

It looks great, I love this photo

Quote from: MountainDon on February 10, 2012, 08:03:32 PMIf you are doing a second story, IMO, the foundation should be located under the side walls, no cantilever. 2x8's would be too small for a 16 foot span on 16" centers. 2x10  #2 SYP or DougFir can span 16 feet,m 16" OC. For 18 ft, 2x12  #2  10" OC DougFir or SYP works.

Handy calculator here

Piers/girder are not prescriptive (code); if there are inspections in your area they may not be permitted. In any event if you use piers see this thread for what is a pretty good bracing system. Scroll down the page slightly from where the page opens.  Note Don_P's comment is Reply #83 further down the page.

Great idea, I'll try it out