Free Standing or...
Attached to the House?

"How am I supposed to know if my porch or deck should be free standing or attached to my house!?"

Actually, it is not too hard to figure out. Porch or deck floors cannot be attached to house walls that have non-structural (that is 'Builder Talk' for thin plywood or wafer board) rim joists along the foundation wall. Back in the day, home builders would cap off the end of their house floor joists with a real structural 2x10 rim joist (back when men were men and women were women), but not so much anymore.

"So what makes a 2x10 'structural' and who cares anyway?"

A 2x10 is structural because it will support weight and sustain lateral forces. If you try to attach your new deck band to an existing house rim joist composed of 1/4" plywood or wafer board (I saw cardboard used in one home), the deck won't stay attached long.

"That is not good. How can I tell if my house has a plywood or wafer board rim joist or a real 2x10? By the way, if I find out he used cardboard, I'm gonna sue him!"

Two ways:

1. If your basement is not finished, simply pull a section of insulation off and see if the rim joist is plywood, wafer board or solid 2x10 (assumes you can tell the difference... some folks can't).
2. If this won't work, here is a good way: Check out your neighbors' decks on houses by the same builder. If their decks were permitted by the county (most are), then the Inspectors will not allow them to attach to the house if non-structural rim joists were used by the builder.

"Don't keep me in suspense. How can I tell from looking at my neighbors' decks?"

You will see a row of 6x6 posts near the house which are supporting a beam and are making the deck free standing.

"Hmm. So then that would mean my porch floor will also have to be free standing?"

Exactly. Your porch (or deck) will also need to be free standing. There are alternative methods (which you and I can discuss), but let’s keep this form simple, ok? Please see my drawing below for all you visual-conceptual learners.