Transforming stock shelving into a custom built-in; installing a new washing machine valve.

Installing a bluestone patio; hanging bikes in a small garage.

Building a custom fireplace mantle; garden edging; repairing a leaking kitchen faucet.

Laying sod in the backyard; finding measurements without doing math; wireless thermostat controls the heating system.

Planting several varieties of palm trees in a front yard; light bulbs; Replacing an old heating system and hot water heater with a more efficient single appliance.

The crew visits New York City, where plumbing and heating expert Richard Trethewey tours a scale model of the city. Host Kevin O'Connor and a local electrician add task lighting to a Brooklyn kitchen. The guys play "What Is It" in Times Square with Jimmy Fallon. Landscape contractor Roger visits the Highline. General contractor Tom installs cable deck railing in Greenwich Village.

Plumbing and heating expert Richard Trethewey heads to Colorado Spings to install a brand new kitchen sink and faucet. General contractor Tom Silva installs insulated sidelights on a front door.

Landscape contractor Roger Cook works with a fencing contractor to install a vinyl privacy fence. Then, Roger, along with host Kevin O'Connor, plumbing and heating expert Richard Trethewey, and general contractor Tom Silva ask "What Is It?" Afterward, Richard replaces a clogged shower valve.

General contractor Tom Silva installs interior window trim. Richard heats a swimming pool using an air conditioner.

Landscape contractor Roger Cook shows a homeowner how to properly mulch his garden beds. Then Roger, along with host Kevin O'Connor, plumbing and heating expert Richard Trethewey, and general contractor Tom Silva ask "What Is It?" Afterward, Richard installs a natural gas line for a barbeque grill.

In the workshop, general contractor Tom Silva demonstrates the proper way to use hand planes. Then, Tom, along with host Kevin O'Connor, plumbing and heating expert Richard Trethewey, and landscape contractor Roger Cook ask "What Is It?" Afterward, Roger helps a homeowner repair a cracked stone walkway.

Host Kevin O'Connor and electrician Scott Caron head to Denver to install a ceiling fan on a cathedral ceiling. Then, Kevin, along with general contractor Tom Silva, plumbing and heating expert Richard Trethewey, and landscape contractor Roger Cook ask "What Is It?" Afterward, Richard visits New Jersey to install a water softener.

Host Kevin O'Connor heads to Del Ray Beach, Florida to restore Terrazzo floors. Then, Kevin, along with landscape contractor Roger Cook, plumbing and heating expert Richard Trethewey, and general contractor Tom Silva ask "What Is It?" Afterward, Tom helps a homeowner repair a cracked floor joist.

Plumbing and heating expert Richard Trethewey heads to Cheyenne, Wyoming, to help a homeowner install a toilet. Then, Richard, along with landscape contractor Roger Cook, host Kevin O'Connor, and general contractor Tom Silva ask "What Is It?" Roger and Kevin patch a lawn with grass seed.

Master electrician Scott Caron helps a homeowner hang a flat-panel television on the wall and conceal all the wiring. Back in the workshop, Scott shows Kevin examples of many different types of electrical outlets. Roger heads to Miami to help a homeowner control the insect pests in her yard without the use of pesticides.

Host Kevin O'Connor meets appliance repairman Richie Isaacson to learn how to maintain kitchen appliances. Then, Kevin, along with landscape contractor Roger Cook, plumbing and heating expert Richard Trethewey, and general contractor Tom Silva ask "What Is It?" Afterward, Tom helps a homeowner install a rain gutter, downspout, and rain barrel.

In the workshop, general contractor Tom Silva and host Kevin O'Connor build a storage bench for an entryway. Then, plumbing and heating expert Richard Trethewey demonstrates how to solder copper pipes properly. Afterward, landscape contractor Roger Cook helps a homeowner maintain an overgrown perennial garden.

Landscape contractor Roger Cook visits a tropical botanic garden to learn how to care for orchids as houseplants. Then, Roger, along with host Kevin O'Connor, plumbing and heating expert Richard Trethewey, and general contractor Tom Silva ask "What Is It?" Afterward, Tom helps a homeowner purchase and install a kitchen wall cabinet.

Plumbing and heating expert Richard Trethewey visits Cortland, Illinois, to learn how corn is harvested and then to help a homeowner insulate ductwork. Landscape contractor Roger Cook demonstrates proper pruning technique. Roger, Richard, host Kevin O'Connor, and general contractor Tom Silva ask "What Is It?" Kevin learns how to maintain washers and dryers.

Plumbing and heating expert Richard Trethewey and host Kevin O'Connor install a ductless heat pump to heat and cool a room. Richard, Kevin, landscape contractor Roger Cook, and general contractor Tom Silva ask "What Is It?" Master electrician Scott Caron demonstrates new technologies and applications for LED lighting. Roger learns how to select houseplants for different situations.

General contractor Tom Silva helps a homeowner solve the mystery of her melted vinyl siding.

General contractor Tom Silva and host Kevin O'Connor demonstrate how to use all types of ladders safely. Then plumbing and heating expert Richard Trethewey replaces a three-handle shower valve with a single-handle antiscald valve.

Master electrician Scott Caron installs several types of surge protection. Then, general contractor Tom Silva, host Kevin O'Connor, landscape contractor Roger Cook, and plumbing and heating expert Richard Trethewey ask "What Is It?" Afterward, Roger demonstrates how to cut and shape stones for hardscaping projects.

How to make and install custom concrete countertops. Can you install watertight connections without soldering? Cordless landscape tools.

The final episode of the 2012/13 season investigates how subway trains are serviced. The crew shows how to paint kitchen cabinets; estimate landscape material by the cubic yard; and how to install a smart thermostat.