The Barnwood Builders float down the Ohio River and land in Paducah, Kentucky, where they try to save a little cabin in a big quarry. The cabin is in rough shape, but these guys don't give up on it. Their time in Paducah is filled with pioneer ingenuity. Alex Makes a chair, Johnny drives a dump truck, Sherman makes a quilt and Mark helps build a barnwood table.

Mark Bowe and the Barnwood Builders take the logs from the Bird's-Eye Barn across the New River and put them back together on a West Virginia island. They have to reconfigure the barn to turn it into a modern fishing cabin with a complicated design. While the crew finishes up, the boss goes to visit the completed Wildrock Pavilion from also from season 3.

Mark Bowe's client wants to use the barnwood from an enormous Pennsylvania bank barn to outfit his Arizona restaurant. It's a beast of a job in the middle of a heat wave, but the Barnwood Builders just won't quit. They save 5,000 board feet of prized barnwood from the cattle stalls, granary floors and 40-foot walls. Mark also pays a visit to another restaurant decked out in barnwood for inspiration.

Tammy Harrah and her late husband dreamed of running a craft store in a log cabin on their West Virginia family homestead. Mark and the guys are helping Tammy and her son see that dream come true by building that cabin for them, making some homemade crafts for the store and visiting a pioneer landmark along the way.

Mark and the guys return to Schuylkill County, Pennsylvania, where they stripped a massive bank barn earlier this year. This time, they are back for the incredible chestnut beams. The roof gives them some trouble, but Johnny's up for the task. They save the central bents, carve up the outer bents and lift out the sleeper logs. Mark visits an incredible bank barn wedding venue and he learns to cut soap stone with a water jet.

The Barnwood Builders head to Cashiers, North Carolina, to build an antique log cabin in the middle of a huge, framed-out modern home. Old wood meets new on this complicated job, and getting it right will take a lot of collaboration. Mark also visits the client's decked-out timber frame barn, and Sherman shows off his horse-wrangling skills.

Mark buys a massive tobacco barn with an incredible log structure hidden inside. He wants to turn the logs into a cabin, so the guys must unwrap the barn layer by layer. It's a tricky job because the barn is filled with hundreds of old poles that fight the guys at every turn. Mark also salvages some barnwood and gets it milled into flooring, and Johnny and Sherman take a trip down memory lane.

Mark's clients want bigger and bigger antique log homes, but the pioneers didn't build big log cabins. They did build big barns, though, so the guys try to build a 1200 square foot cabin using barn beams from their Boneyard inventory. And Mark's friend shows up to make a one-of-a-kind whiskey tap out of an unused beam end.

Not far from the Boneyard, the town of White Sulphur Springs was devastated by a recent flood. Mark and the guys step up to help their neighbor rebuild, Barnwood-style. They repair a garage by wrapping it in barnwood and use log skins to transform a prefab shed into a log cabin playroom. Mark also visits a modern Montana home covered in log skins.

Mark Bowe and his crew get a strong dose of family history in Leivasy, West Virginia, where they work on saving the O'Dell family's hand-hewn log home. Mark also spends some time with his own father and visits a log cabin built by his great-grandfather.

Mark challenges his crew to build a log fort on the Boneyard. They use spare logs and some serious hillbilly know-how to construct a pioneer cantilevered fort, but when the temperature takes an unexpected plunge, the job becomes more difficult.

The Barnwood Builders find themselves in unfamiliar territory as they transform a nearby office space into a showroom for their business. They use vertical barnwood, horizontal barnwood and a timber frame facade. Then they finish off the room with barn doors, hand-crafted items and reclaimed roofing tin.