Help understanding max span of pier and beam foundation?

[TylerGA]

Hey y'all!

First post for me! I am posting this from north east Georgia, also known as the piedmont region of the state. I have gone through several iterations of a 2 bedroom 1 bath cabin. I believe I have settled on one that will be set on a pier and beam foundation. Cabin measurements 24 foot wide by 36 to 40 foot long. Rafter system with vaulted ceilings. Two bedrooms far end divided roughly 12x12 each hall way along 36-40 outside walls in a mirror fashion with a shared bathroom accessible through individual walk-in closets and closet area have a lavatory sink and vanity cabinet again each side. Toilet and shower shared. So the closets/Bathroom share wall with separate mirrored bedrooms then opposite wall in the closet and bathroom share wall with a small kitchenette with cabinets and a narrow island. That would be opening to a 24 x 18/22 , again not exactly set on length, center of the 24 wall would ideally have a large opening doorway to a deck covered by continuous vaulted ceiling to outdoor living space. Well again ideally! 

Ok my family owns a portable storage building business here that is actually only 2 miles from my cabin proposed future location. We order lumber by the transfer truck loads. Based on market prices, We get white wood #2 choice 2x4s 14 and 16 ft long, 2x6x14 and 16ft, yellow pine # 3 2x6x12, yellow pine pressure treated #3 2x6x12 and 2x4x10. We get 4x8 3/4 TG engineered strain board, 4x8 1/2 osb, and I believe that's all our "normal" lumber we have readily available. We build our building 8,10,12,14 wide using a similar beam system we call skids. 8,10,12 all have skids 6ft apart from each other centered running length wise. Or 3ft from center of the width of each. 14 ft has 4 skids. Skids are all laminated by us and then notched 1 1/2 inch depths 24,16, and requested 12" on center

Ok so my main question is on a single story structure I explained earlier. How far should I lay beams how far should their joists be spanned and set apart? I am trying to use our lumber in house for multiple reasons. Mainly it will be cheap as heck for me to do so. Last I checked Yellow pine boards were $4.50 a board!! I am ole with buying larger nominal sized boards for outside bands and beams but want to use 2x6 up for joists. What are my pier spacing what are my beam spacing? 

Anything that someone or all of you could shed light on for me would be helpful. I hope I can make it look very nice and get it built quickly! I want to get a price worked up and advertise it to public for purchase as on site built and possibly a double wide shop made structures later on if able to sell. 

Thanks! 
Tyler

[MountainDon]

Question. Does the location you intend to construct this cabin require a building permit? That usually means following a building code. Pier and beam foundations normally will not meet code. The IRC is used in GA and does not recognize pier and beam.

Comment. In the last paragraph you mention possibly building a shop made double wide. Commercially available single and double wides are built on welded steel beam frames, not wooden beams for very good reason.

[leonarht]

Hey y'all!
First post for me! I am posting this from north east Georgia, also known as the piedmont region of the state. I have gone through several iterations of a 2 bedroom 1 bath cabin. I believe I have settled on one that will be set on a pier and beam foundation. Cabin measurements 24 foot wide by 36 to 40 foot long. Rafter system with vaulted ceilings. Two bedrooms far end divided roughly 12x12 each hall way along 36-40 outside walls in a mirror fashion with a shared bathroom accessible through individual walk-in closets and closet area have a lavatory sink and vanity cabinet again each side. Toilet and shower shared. So the closets/Bathroom share wall with separate mirrored bedrooms then opposite wall in the closet and bathroom share wall with a small kitchenette with cabinets and a narrow island. That would be opening to a 24 x 18/22 , again not exactly set on length, center of the 24 wall would ideally have a large opening doorway to a deck covered by continuous vaulted ceiling to outdoor living space. Well again ideally!
Ok my family owns a portable storage building business here that is actually only 2 miles from my cabin proposed future location. We order lumber by the transfer truck loads. Based on market prices, We get white wood #2 choice 2x4s 14 and 16 ft long, 2x6x14 and 16ft, yellow pine # 3 2x6x12, yellow pine pressure treated #3 2x6x12 and 2x4x10. We get 4x8 3/4 TG engineered strain board, 4x8 1/2 osb, and I believe that's all our "normal" lumber we have readily available. We build our building 8,10,12,14 wide using a similar beam system we call skids. 8,10,12 all have skids 6ft apart from each other centered running length wise. Or 3ft from center of the width of each. 14 ft has 4 skids. Skids are all laminated by us and then notched 1 1/2 inch depths 24,16, and requested 12" on center
Ok so my main question is on a single story structure I explained earlier. How far should I lay beams how far should their joists be spanned and set apart? I am trying to use our lumber in house for multiple reasons. Mainly it will be cheap as heck for me to do so. Last I checked Yellow pine boards were $4.50 a board!! I am ole with buying larger nominal sized boards for outside bands and beams but want to use 2x6 up for joists. What are my pier spacing what are my beam spacing?
Anything that someone or all of you could shed light on for me would be helpful. I hope I can make it look very nice and get it built quickly! I want to get a price worked up and advertise it to public for purchase as on site built and possibly a double wide shop made structures later on if able to sell.
Thanks!
Tyler

It sounds like you have a well-thought-out plan for your cabin. For a 24-foot wide cabin, you can use 2x6 beams spaced 16 inches on center. This will provide adequate support for the roof and floor loads. For 2x6 joists, you can use a maximum span of 8 feet. If you want to use a longer span, you will need to use larger joists or engineer the floor system to handle the additional load. The pier spacing will depend on the soil conditions and the weight of the cabin. However, a good rule of thumb is to space the piers no more than 8 feet apart.

[billy boy]

Considering you've got access to a bunch of lumber, you could save a ton. For the pier and beam setup, I'd say go with beams at least every 8 feet. That's pretty standard, and for the joists, 2x6s should work fine if you're keeping them around 16 inches apart. Keeps things sturdy without overkill.