There are several aspects of a deck that make it feel solid. Joist width is just one, and according to the AWC chart you're ok up to 13 feet even with 24" OC spacing.

To make it solid, space the joists closer together, put blocking in at mid-point, put diagonal bracing between the posts and beams/joists if it's high off the ground. I think a 2x12 would be overkill, though it certainly wouldn't hurt.

Here is a link that might be useful: AWC Guide (see page 3 for joist table)

Thanks... and I forgot to mention that I'm planning to space at 16"OC.

We don't use southern yellow pine. We only have douglas fir. For a 12' span, we use 2x12's. I think that your material is a little stronger, so maybe you are OK.

One thing to remember about the tables. They are the minimum allowed size that meets the criteria. That does not mean that they will feel solid, only that they won't fail. I always go up one size.

Mark

Thanks Mark. Your point about the tables is exactly why I posted this question... I want a solid feeling deck in addition to one that meets the minimum code but don't have the practical experience to know if the 2x12 is necessary to accomplish this.

Chris

Chris, I agree with the Weed.

Using biger joists wont take out the bounse on their own its all in the span. With your project runing one or two rows of blocks will help a lot.

John Hyatt www.deckmastersllc.com