Grooved Post and Tongued Wall

Hello, this is my first post here. I tried searching for this topic so excuse me if this has already been done before. I am creating a shed, the dimensions of which, I am thinking 16x8 or 16x10 feet. I want to build the shed with joinery. I was thinking of making the walls out of 2 by lumber, probably 2x10 or 2x12. I have 4x4 inch 8 ft long posts which i would use for sills and corner/edge posts. I want to be able to slide the walls into the posts, and the best way i thought to do that, is to create a vertical groove on the posts, 1/2 in wide, maybe 1/2 inch deep. The ends of the 2 by lumber would have a corresponding 1/2 inch wide and deep tongue. I was thinking of creating the groove 1/2 inch from the outer edge of the post, so that when i slide the 2 by wall boards in, the outside face of the post and wall are flush. My main concern is the amount of space from the outside edge and the groove on the post is only 1/2 inch. If i were to put a lot od pressure on the walls from the inside, would this possibly cause the post to split along the grain? I could align the groove to be in the middle of the post, but then the 2 by walls would not be flush with the outside. Any advice is appreciated!

Hi C,
Welcome to Permies.

I am not a professional builder, but I have done my fair share of remodels and helping others. A tongue that is only 1/2 inch deep doesn't sound like enough. I love timber framing with joinery, but I think there is a reason they tend to use bigger pieces. You could probably do it with all 4x4 lumber, but I worry that mixing the 2x lumber will complicate things more than needed. Is there a reason you want to use joinery versus a "stick" built shed?

Sometimes I can get enamored with a particular tool or technique and try to force it into my situation. I think sometimes we need to step back and say... what is the best option here, regardless of what I like. And maybe it still is joinery because you want to try it out. That is awesome. I would just get some bigger pieces of wood and look up some videos on the various types of connections. If a stick built frame would work better here, why not give that a try?

Hi C, welcome!  I suspect the 1/2" of wood on the outside of the post groove would be strong enough unless you're really having a party inside that shed.  My concern would be that if anything shifts a little bit on your building, the walls may fall out of that 1/2" deep groove.

Crazy idea...  What if you didn't have corner posts at all?  Just have the wall boards meet in the corner.  Maybe have one go past the other (butt and pass log construction style) and screw them together.  That corner should be fairly strong and able to hold up a roof structure.  Plus then the whole wall will expand and contract with the seasons together.  

(they wouldn't have to go past each other as much as in this picture, just enough to complete the corner)