My 1858 porches seemed to be the same as the inside (5/4 T&G heart pine) and we replaced it with the same thickness T&G, although not in heart pine.

The entire porch floor was *just* replaced on my house! Only one of the local lumberyards carried the 5/4 t&g flooring (fir), so just keep looking until you find it.

It does look beautiful -- very much like the interior oak flooring! They recommended Wolman's Finish to protect it, and said to apply it to all sides (especially the t&g) before installing. That was my job, and I used 'natural'. :) Here it is! I still need to apply the 2nd coat...

@party music 05 ~ your flooring looks beautiful!
We had our front porch remodeled last summer. The floor was replaced with doug fur t & g that is (I'm guessing) about 1/2 inch thikness. It was originally at least 1 inch thick... I wish we could have replaced with something thicker but it was going to cost far too much to aquire... It looks nice, but walking on it you can feel the difference. Good luck and make sure you get something you will be happy with!

Thanks for the information, and the pics are wonderful party!
I suppose that traffic wear is the only reason I need to replace the flooring in front of the door--the rest is fine. :) I plan on painting it grey as it is now, so I'm hoping for an inexpensive grade of wood. What the real problem is will be revealed when I take up the damaged flooring--I am 90% sure the joists need sistering or something, since there is a definite dip in the level.
On a side note re flooring--my interior floors do not have subflooring--my oak is laid directly across the joists--confirmed when I cut a new hole for a register in the living room!
My porch columns are square and fluted, wish I could find matching lumber to remake my mini-columns on my steps!