A skirt typically consists of a lattice panel set into a wood frame. In older homes, it's often built of untreated pine or fir, neither of which is very resistant to decay and bugs. In time, the parts closest to the ground begin to rot and the decay spreads to the lattice. In regions that receive a lot of precipitation, wood rot can begin to appear in less than two years.
Occasionally a skirt doesn't have a framework and simply consists of a lattice screen attached directly to cleats nailed to the understructure framing. (The porch we worked on had this type of skirt.) While a frameless skirt is easy to install, it's also susceptible to warping and damage because the lattice has very little support. Here we built a durable new skirt using pressure-treated lumber and TuffBilt plastic lattice. We also opted for an unconventional installation method. Rather than permanently attach the frames, we hung them on hinges so the homeowners could use the space below the porch for storage. The swing-up frames also make it easy to crawl underneath the porch to repair the framing if needed. The techniques used here can also be adapted for replacing lattice on a deck, fence, gate, privacy screen, or trellis.