Skunks Under Sheds, Porches, & Decks
The best defense against getting skunks underneath parts of your property is to do exclusion work around your proeprty before it is a problem, or as you are completely home improvement and renovation tasks. Not all of us think this far ahead, and don't plan for disaster though, so in order to get rid of skunks and keep them away from your sheds, porches, and decks, you will probably need to trap them.
Don't Try to Scare Skunks Away
We all know what skunks do when they are scared. It's not pretty and it's not pleasant to the nose, so don't try to scare a skunk away. You can trap or lure it away from your property, or if it is only passing through periodically and not making a home on your homestead, you can exclude it, but whatever you do, don't try to shoo it away.
Excluding Skunks That Don't Live On Your Property
If the skunk isn't living on your property, but goes underneath your shed, deck, or porch, it now lives there. Always assume the skunk is living on your property. If it wasn't before, it probably just found some tasty food and is setting up shop immediately. You'll have to trap this skunk now in order to relocate or exterminate it, depending upopn what local laws allow you to do to skunks.
Skunk Exclusion Methods
Excluding skunks is very similar to excluding other wildlife species that invade your yard. You can do so with steel mesh and some lumber, placed around the edges of raised structures, like sheds, porches, and decks. You can cover pre-contructed crawl space and skirting entrances with the mesh as well, but be careful not to trap a skunk inside, or it will likely die and cause an awful smell to rise from your outdoor structure.