|
| Author |
Message |
MrDoug
Member
|
# Posted: 22 Oct 2025 04:47pm
Reply
I was advised to start a new thread, so replies to my questions do not get mixed up and lost, so here we are. I am still in the " thinking about it " stage. I have narrowed my site selection to two. I want a 12x16 one room cabin with a 4 ft porch. Total footprint is 16 square. Expected load inside is an air mattress, tent sized wood stove ( about 20 lbs), card table, plastic chairs. MAYBE a bookshelf. Planning on 1/2" plywood floor. I'm almost 60, so cost is much more important than longevity. What do yall recommend as far as floor joists (spacing, size, etc)? Joists will be supported by 4x4 posts set in concrete 6-8" below frost line.
|
|
gcrank1
Member
|
# Posted: 22 Oct 2025 07:13pm - Edited by: gcrank1
Reply
Fwiw, I have a 10x16 prebuilt gambrel roof shed as my toolshed/workshop. It is built in typical prebuilt shed fashion on 2 full length runners beneath.
I have those sitting on prepped/leveled ground with 4 solid cement silo slaves per side; this is what is called a 'floating foundation'. Ime plenty good for that class building and easy to check and shim for level in the future IF needed.
I suggest keeping in mind that what one puts in just keeps getting heavier over time and a bouncy floor isn't good. A little overkill on the bottom of the build wont be regretted later.
|
|
Fanman
Member
|
# Posted: 22 Oct 2025 08:54pm
Reply
Quoting: gcrank1 I suggest keeping in mind that what one outs in just keeps getting heavier over time and a bouncy floor sink good. A little overkill on the bottom of the build wont be regretted later.
^^^ This. ^^^
The span tables say 2x8 joists on 16" centers or 2x10 on 24" centers if they're going the short (12') way. Even if you're not required to follow any code, in this case it makes sense.
Similarly, I'd go with 3/4" plywood for the floor.
|
|
DRP
Member
|
# Posted: 22 Oct 2025 09:38pm - Edited by: DRP
Reply
#2 for ^^^This^^^
Here, code ain't the man, its physics.
We'll get to that foundation  .
|
|
MrDoug
Member
|
# Posted: 22 Oct 2025 10:20pm
Reply
I'm not planning to span 12 or 16 feet. I'm thinking more along the lines of two 8x16 rectangles bolted together, with 2x6s spanning 8 feet. And again, I'm not planning on parking a truck inside. Just an air mattress, card table and plastic chairs. I would actually be the heaviest thing in there.
|
|
DRP
Member
|
# Posted: 23 Oct 2025 06:12am
Reply
A picture is worth a thousand words.
If the porch floor is the cabin floor it is going to be much harder to keep water out.
|
|
Fanman
Member
|
# Posted: 23 Oct 2025 08:20am
Reply
Quoting: MrDoug I'm not planning to span 12 or 16 feet. I'm thinking more along the lines of two 8x16 rectangles bolted together, with 2x6s spanning 8 feet.
In that case your 2x6s can be on 16" centers, but you'll have to look at the strength of the 16' long beams. They'll need to be pretty heavy or supported at multiple points along their length.
Quoting: MrDoug And again, I'm not planning on parking a truck inside. Just an air mattress, card table and plastic chairs. I would actually be the heaviest thing in there.
Understood, it's just a matter of how tolerant you are of walking on a springboard, and whether your needs will change later. Also a structure that's constantly flexing means nails working loose, etc. In the end, the cost difference between doing it right and "just enough" is small enough to be forgotten in a few years, but a bouncy floor will not.
|
|
Brettny
Member
|
# Posted: 23 Oct 2025 10:32am
Reply
They make sheds 12x16..then just add on a porch. I wouldnt bother with putting concrete or posts in the ground on such a small building. Just blocks on the ground is fine.
|
|
|
MrDoug
Member
|
# Posted: 23 Oct 2025 12:12pm - Edited by: MrDoug
Reply
Initial plan for floor joists. Red squares are 4x4 posts, green are 2x6x16, black 2x6x4. Couple of different spacing, but scale was wrong.
|
|
gcrank1
Member
|
# Posted: 23 Oct 2025 05:10pm
Reply
We built our 1st cabin by hand in '83-'84 so I understand the attraction of 'building yer own'.I was inclined to do the same for the toolshed/workshop but time and my health issues didn't let that happen. We went looking at prebuilts and found one 'clearanced out' and for $50 delivered. I initially wanted a 12x16 but settled for the 10x16....it would make a pretty decent small cabin for 1 or 2 in a moderate climate and be ready to moving in and use.
Then you could enjoy it right off and spend your time building a front porch, etc.
|
|
DRP
Member
|
# Posted: 23 Oct 2025 09:10pm
Reply
Doodling...
The posts are 6x6 treated on footings. The walls brace the posts as they continue beneath the floor, there is not a connection there as with a pier and beam, this is rigid.
The floor perimeter is double 2x10's, the connectors are Simpson HUC210-2's. The joists are 2x8.
Without knowing snow load the roof is a WAG, 2x6 rafters, double 2x10 elsewhere.
Wall and wrap that box, drop the deck ledger a couple of inches below floor height inside to keep rain and leaves out, flash behind and then over the deck ledger (flash and counterflash) and that will not be an issue.
9 proper holes vs 25 gopher holes and a whole lot stronger.
I'm not a fan of a tiny porch, that is where it is at .
|
|
MtnDon
Member
|
# Posted: 23 Oct 2025 09:16pm
Reply
tiny porch... a 4-foot-wide porch is too small for a comfy chair and space to walk.
|
|
MrDoug
Member
|
# Posted: 23 Oct 2025 09:39pm
Reply
Strong possibility. Porch is tiny, simply because I am on a mountain, and finding even 20 square feet that is relatively level has been a challenge. I dont have the equipment or strength anymore to level too much ground.
|
|
gcrank1
Member
|
# Posted: 23 Oct 2025 10:50pm
Reply
A porch dosnt need level ground, the deck posts make up the diff to make a level top
|
|
Brettny
Member
|
# Posted: 24 Oct 2025 06:39am
Reply
So your floor joists are going to have a 4' on center spacing with 1/2in subfloor? With 25 vertical 4x4 to hold it up?
|
|
|
