Decks, Patios, Porches and Docks - Rubber tire edging under skirting?

Hi, I just installed skirting around the PT deck I'm building. The skirting is made from vertically aligned 5/4 decking, screwed to the header/rim joists at the top and to a 2x2 that runs along the inside bottom. Both the 2x2 and 5/4's are sitting on the dirt. I'm thinking I could get a few rolls of that rubber edging made of recycled tires, dig out under the skirting and put the edging under the 5/4 exposed end. Would that help cut down rotting over time? Wondering if it'd be worth it.

Since the 2x2 will warp in short order, you will be rebuilding it, so why not just cut the 5/4 boards short allowing natural drying cycle when it rains and get them out of the dirt? And replace the 2x2 with a 2x4 for sturdiness between posts, and keep them all out of the dirt.

Hi Chandler, the plans actually call for a 2x4 along the bottom, with stakes into the ground every 5 ft or so, and then the stakes are screwed to it... but since the skirt height is fairly short (26 inches 3/4 of the way around the deck, and 34 inches the rest), I thought I'd rip the 2x4 and use one piece along the bottom, and the other about half way up. Keep in mind each 5/4 skirt is screwed to the 2x8 header or rim joist. Do you think the 2x2 will warp so much with all the 5/4 boards nailed to it and screwed to stakes? Is yes, then maybe I should replace them (argh, the pain, the pain... :-) The plans just say they should sit on the dirt, but I thought the rubber would help... I really do not want any space between the bottom of the skirt and the ground.... I'll post a pic to the web site (forget the name - bucket or something... I posted my deck stairs there a while back... btw, my stairs are now all done, including the stair lights - I'll post a pic of them too :-) The skirting will be screwed to the 2x2 once I add the 1x4 trim along the bottom - so that should be taken into consideration as well... I could prob leave a small gap between the bottom and the rubber.... I'm just thinking the rubber would help ensure no dirt gets scuffed up under the skirting and ending up with the cut end of the 5/4's sitting in the dirt, like they are now.

Your OP didn't say how tall the skirting was, and I live in the mountains where our decks are sometimes 20' high on one side, so I had a different picture in my mind. You may be ok with the 2x2 on the bottom, as minimal warping will take place on such short 5/4 boards. Longer ones...not so. You could use the rubber material, OR buy a bundle of shingles, split them lengthwise and use them upside down under your pinning. May prove to be a little less expensive with the same result. Worth mentioning.