Advice on post sizing

[jfruge]

Hello everyone,

I am in the planning phases of building a timber frame shop. Location is on the gulf coast in Louisiana. About 40 miles inland. No snow down here. I plan on doing a 24x40 gable style. Bents spaced 8 ft. 16 feet of the shop will be a man cave portion. Will have a cathedral ceiling exposing the beams. Stairs will be there to access a loft which will be over the shop portion. The shop portion will be the the remaining 24 feet of the shop. In the future I plan on putting a lean to car port on the side using cypress for the post and beams. My roof will be standard asphalt shingles. I live in a subdivision so we can't have a metal roof. My siding will be a wainscoting stone veneer with hardie plank all the way to the top.

My question is what size post should I use. Would 6 x 6 be enough? For my tie beams I would go with a 6 x 10. Or do I need to step it up to 8 x 8? As far as the bent goes I would have a center post at 12 ft. The truss style for the loft would be queen post. I plan on setting this structure on a finished slab with connectors. I am also stumped on rafter sizing and spacing. I've thought about 12 and 10 foot bent spacing but 8 ft. spacing is what best suits my floor plan. I will be using yellow southern pine because it is local and easy to get down here. I figure the shorter spacing of bents would add more support.

Thanks for any advice,

James

[Don P]

It might work, you'd need to run the loads and see if there is enough wood for joinery. In that style of loft it usually has either clearspan below with a truss or runs 2 rows of posts. This is a sketch for a local barn repair a friend is working on, it is about 25x40 and is pretty typical around here;

[jfruge]

Than you. I've used your calculations in the tool box. Very helpful. I plan on putting my top plate about 3 feet over my tie beam to give me a little more room for storage in the loft. I've seen a lot of diagrams for joints using larger post. Is their any diagrams on this forum for joints with 6x6 post? I know the tenon has to be an 1 1/2 inch wide.

[canopy]

It's good to use 8" posts minimum for comfortable joinery. Consider for instance 2 knee brace mortises across from each other. Of course joints could be staggered or stubbed, but I also don't find the appearance of posts less than 7" aesthetically pleasing as they appear undersized even though structurally sound.