Originally Posted by jk333
Can you please explain this? im still a little confused. THanks
Span tables show how far you can reach out with a beam to hold up a fixed amount of weight.
You can change the amount of weight a structure can hold in several different ways.
Go with thicker beams like a 2x10 instead of a 2x8 or you can put the beams closer like 16 inches apart rather than having them 24 inches apart.
This is the simple explanation and it is more complex than that but this is the general idea.
It does snow in Tacoma and when it does it has high water content (it's called Cascade Concrete). This means when the snow comes down it has a lot of weight compared to snow with a much lower water content. Or even worse freezing rain that can't get much heavier.
You don't want to have to worry about rushing home and shoveling off the roof every time it snows or worse yet, wake up to see your roof on the floor of your shop.
Tacoma has a snow load code that you should search out and see what they require.
With a shed roof design my guess is that you will have to put in a center support of some sort.