ship lapping two 6x6 beams

[hemlock man]

Hi Everyone, I'm in the beginning stages of building a 16'x20' sugar house. My plans call for (3) 20' skids to use as the foundation. Floor joists will go on top of the skids.  I am having a difficult time tracking down 20' 6x6 skids for the foundation. I was considering sistering up two 10 ft 6x6 with a half lapped joint. I was told the lap should be 4' in length and oriented so the seam is facing up. This building is going on 9 piers so I would have three of these skids with the lapped portion centered up on the middle piers.I was going to use (3) 1/2 inch carriage bolts to hold the joints together.
I'm new to this so I wanted some advice from others. what do you guys think?

thank you
Dave

[Roger Nair]

Even though I don't know the loads, 6 x 6 seems too light.  I would guess that you would need at least 6 x 8 as perimeter beams and 6 x 10 for center beam.  A simple bolster could be a better solution than a half lap scarf.

[hemlock man]

Thanks Roger. Not sure on the loads either, but I want something that's going to last. Jeez, I figured if I bought a set of I wouldn't have to worry about this stuff... 
Would ganging up 2x6's, four deep using 12' and 8' pieces be a better option?

[Roger Nair]

Sure can gang up two by lumber but 6 inch beams seem to light.  What is the weight of the evaporator plus sap and firewood?  A central beam will pick up most of the weight, even with a short 10 foot span, a ten inch beam seems more up to the task.  You need to develop the relevant facts.

[Roger Nair]

Better yet, why not put the evaporator floor on earth, crushed stone or a slab of concrete.

[hemlock man]

Its a small evaporator, I'd say 250 pounds. Firewood will be outside. The building site has a pitch to and getting acess with a concrete truck is not possible, so I went with piers. I'd like to store things like a gator and quad during off season. That's it for heavy stuff

[hemlock man]

TheRe are 9 piers all together. Pier square is 154 inches by 208 inches. floor joists will be 2x6 on end and will overhang the piers to get a 16x20 floor plan.
All rough cut full dimension