Please Help Me With Joist Beams For Cabin

For the love of all that is good, this part is breaking me and I need help. For context: I am building a 12 x 14 foot shed/cabin in the woods with a small loft in a inverse facing lean-to style roof and I am wholly lost on what I should do for the lumber I should use which will be what I'll be dropping my joists on to. The problem I'm facing is that what I am being told is "more than enough" extremely adamantly by someone feels like I am being set up for disaster either immediately or down the road through wearing. Here's an artistic rendering of what I'm hoping to build. The nitty gritty: I'll be using Pylex 50" helical screws for the foundation since this will help break the frost line and easier to do than sonotubes due to the remote location in the woods. This will be a drop-in joist where the joists themselves will be resting on the bottom cross beams. The loft-space will exist on top of the only walled-off room in the building and won't span across the length (unless it structurally needs to) The two blue x marks on the poor beam drawing are two concrete deck blocks built on a bed of gravel to help support that space which is otherwise empty for the middle beam. Four support piles in the front and back to support the roof-bearing walls. Okay, so, I hope this gives an idea as to what I am working on. Going back to the problem, I am being told by this person that I can build the foundation cross beams with 2x6 PT lumber which feels VERY thin even without live weight. I explained that I don't want a floor that'll bounce the fridge when I walk by it and he's so sure it won't meanwhile I feel like I should, at the very least, sister the 2x6 cross beams for load bearing but would more comfortably go with 2x8s. It's mine but he kind of has a way to really make me feel stupid even if 2x8s is over building; i'd rather spend the extra $100 on materials and make it rock solid than get caught with a bouncy castle. Any particular advice on whether I am overreacting and 2x6 is fine or should I move up to 2x8? Bonus: Would 2x6 16" OC be fine for the joists or should those move up as well? submitted by /u/Todesfaelle [link] [comments]

Mar 31, 2025 - 15:39

For the love of all that is good, this part is breaking me and I need help.

For context: I am building a 12 x 14 foot shed/cabin in the woods with a small loft in a inverse facing lean-to style roof and I am wholly lost on what I should do for the lumber I should use which will be what I'll be dropping my joists on to.

The problem I'm facing is that what I am being told is "more than enough" extremely adamantly by someone feels like I am being set up for disaster either immediately or down the road through wearing.

Here's an artistic rendering of what I'm hoping to build.

The nitty gritty:

I'll be using Pylex 50" helical screws for the foundation since this will help break the frost line and easier to do than sonotubes due to the remote location in the woods.
This will be a drop-in joist where the joists themselves will be resting on the bottom cross beams.
The loft-space will exist on top of the only walled-off room in the building and won't span across the length (unless it structurally needs to)
The two blue x marks on the poor beam drawing are two concrete deck blocks built on a bed of gravel to help support that space which is otherwise empty for the middle beam.
Four support piles in the front and back to support the roof-bearing walls.

Okay, so, I hope this gives an idea as to what I am working on.

Going back to the problem, I am being told by this person that I can build the foundation cross beams with 2x6 PT lumber which feels VERY thin even without live weight. I explained that I don't want a floor that'll bounce the fridge when I walk by it and he's so sure it won't meanwhile I feel like I should, at the very least, sister the 2x6 cross beams for load bearing but would more comfortably go with 2x8s.

It's mine but he kind of has a way to really make me feel stupid even if 2x8s is over building; i'd rather spend the extra $100 on materials and make it rock solid than get caught with a bouncy castle.

Any particular advice on whether I am overreacting and 2x6 is fine or should I move up to 2x8?

Bonus: Would 2x6 16" OC be fine for the joists or should those move up as well?

submitted by /u/Todesfaelle
[link] [comments]