I have a question, I have a porch that is eight feet wide and fifty foot long across the front with twenty four feet on each side of the house with 2x6's for rafters and ceiling joist (16" center) and 5/8 plywood for roof sheathing, this is site built with a 35 year shingle, I have 3-2x10's for a porch beam, can anyone tell me the maximum span I can have between porch columns? Also the porch columns I have are aluminum 6x6 square rated at 23000 lbs.
I hope I gave enough info, all replies will be greatly appreciated.
Thanks

Are you considering taking down some posts and then increasing the distance between them?
What kind of wood is the 2x10's? What is the nailing pattern holding them togeather? All this factors into the span.
Do not forget the support holding up the columns. The farther apart they are the more weight they must carry. This translates into larger footings below each column. You cannot place the newly located columns between existing columns locations and expect the porch flooring to support the weight.

Thanks for the reply, this is new construction with only temporary support and the 3-2x10 beam is southern yellow pine with a nailing pattern of 4 nails vertical about 6"-8" apart, the footing around the porch is 8"deep and 24" wide of 3000lbs concrete with 3/8" rebar, the porch has a 5 coarse high 8x8x16 concrete block wall and has brick around the outside of the porch, the columns will sit half on the brick and half on the porch floor. What would you suggest as a span between columns?
Thanks again for the reply.

The span of the beam and the locations of the columns is governed by the lengths of the individual 2x10's. All joints in the 2x10's should occur directly over columns, unless the beam is specifically designed by a qualified professional as something other than a simple beam. If someone just spliced three 2x10's together willy-nilly, you don't have a 3-2x10 beam, and you may not even have the equivalent of a 1-2x10 beam.

Thanks for the information, in one location of the beam two outside 2x10's are spliced together with the middle 2x10 running solid and splicing in a different location, most of the beam is solid and never does all 3-2x10's break in the same location.
thanks again

In that case, you haven't got a 3-2x10 beam. All the joints in all the members must occur at a support, unless the beam is specifically designed (engineered) to be constructed otherwise.

What you have is either a single 2x10 or a double 2x10, depending on the locations of the joints relative to the column locations. It's possible that in some cases you have 0-2x10, and that won't support very much.