Plumbing and heating expert Richard Trethewey kicks off the 9th season of Ask This Old House by helping a homeowner in Canada install a new kitchen sink. Then, up in the loft, general contractor Tom Silva shows host Kevin O'Connor some tools that no home workshop should be without. Then, landscaping contractor Roger Cook and arborist Matt Foti rescue a tree from "volcano mulching.

General contractor Tom Silva helps a homeowner install balusters on his new staircase. Then Tom, along with host Kevin O'Connor, plumbing and heating expert Richard Trethewey, and landscaping contractor Roger Cook ask, "What is it?" Then, Roger helps a homeowner install a new stone footpath.

General contractor Tom Silva helps a homeowner find additional storage space by creating a new doorway into an unused attic. Then Tom, along with landscaping contractor Roger Cook, host Kevin O'Connor, and plumbing and heating expert Richard Trethewey ask, "What is it?" Afterward, Richard shares a viewer tip on how to create a faucet wrench from a standard PVC pipe. Then, Kevin and an electrician help a homeowner repair a broken doorbell.

General contractor Tom Silva helps a homeowner repair a rotted windowsill. Then Tom, along with host Kevin O'Connor, landscaping contractor Roger Cook, and plumbing and heating expert Richard Trethewey ask, "What is it?" Then, Roger shows Kevin a few gardening tools designed for people with limited mobility. Afterward, Richard helps a homeowner install an outdoor faucet.

Landscaping contractor Roger Cook builds a raised garden bed that is accessible by wheelchair. Then, general contractor Tom Silva shows a homeowner how to repair a leak in his roof caused by a worn-out plumbing vent gasket.

Landscaping contractor Roger Cook and plant expert Carrie Kelly discuss different types of groundcover. Then, plumbing and heating expert Richard Trethewey helps a homeowner warm up her cold living room by installing new hydronic baseboard heaters. Afterward, back at the workshop, general contractor Tom Silva shows host Kevin O'Connor a new product that makes it easier to mark and cut openings for electrical outlets in wallboard.

Landscaping contractor Roger Cook heads to Fargo, North Dakota, where he and a local crew help a homeowner build a new circular patio and fire pit. Then Roger, along with host Kevin O'Connor, general contractor Tom Silva, and plumbing and heating expert Richard Trethewey ask, "What is it?" Then, Tom and Kevin head outside to repair a set of brick stairs.

General contractor Tom Silva helps a homeowner install a new energy-efficient storm door. Then, up in the loft, plumbing and heating expert Richard Trethewey shows host Kevin O'Connor how to cut and solder copper plumbing pipes and fittings. Then, landscaping contractor Roger Cook helps a homeowner reduce the size of an overgrown privet hedge.

Landscaping contractor Roger Cook helps a homeowner repair an uneven stone patio. Then Roger, along with host Kevin O'Connor, general contractor Tom Silva, and plumbing and heating expert Richard Trethewey ask, "What is it?" Then, Kevin and painting contractor Mauro Henrique help a homeowner repaint a rusty metal bulkhead door.

Plumbing and heating expert Richard Trethewey helps a homeowner heat his newly remodeled kitchen by installing hot water radiant tubing underneath the floor. Then Richard, along with host Kevin O'Connor, landscaping contractor Roger Cook, and general contractor Tom Silva ask, "What is it?" Afterward, Tom shows Kevin how to apply joint compound to drywall corners. Then Roger and Kevin head outside for a few lessons on using a wheelbarrow properly.

General contractor Tom Silva helps an old friend repair the loose carpeting on his staircase. Then, landscaping contractor Roger Cook shows host Kevin O'Connor several different types of shovels and other tools for digging. Afterward, Kevin heads to Pasadena, California where he and a local electrician help a homeowner install recessed lights in a kitchen ceiling.

Plumbing and heating expert Richard Trethewey helps a pair of homeowners reduce their utility bills by installing a new forced-air furnace and air conditioning system. Then, general contractor Tom Silva helps a homeowner repair damage to her oak flooring that was caused by a leaky radiator.

Plumbing and heating expert Richard Trethewey helps a homeowner install a second sink into an existing bathroom vanity. Next, landscaping contractor Roger Cook shares a viewer tip that makes yard clean-up a little easier. Then, general contractor Tom Silva helps a homeowner repair a large crack in his concrete block foundation.

Landscaping contractor Roger Cook shows host Kevin O'Connor a few helpful techniques for mowing a lawn. Then, general contractor Tom Silva helps two homeowners begin building the backyard deck of their dreams.

General contractor Tom Silva helps two homeowners complete the construction of their new backyard deck. Then, back in the workshop, Tom shows host Kevin O'Connor a few other types of hidden deck-fastening systems.

Landscaping contractor Roger Cook shows host Kevin O'Connor a few ways to deal with rainwater from gutters and downspouts. Then, up in the workshop, plumbing and heating expert Richard Trethewey talks "All About" pliers. Then Roger, Kevin, Richard, and general contractor Tom Silva ask, "What is it?" Afterward, Tom and Kevin insulate an attic floor using fiberglass batts and blown-in insulation.

Up in the workshop, expert painter Mark O'Lalor shows host Kevin O'Connor a few tricks and techniques for painting an interior wall. Then Kevin, along with landscaping contractor Roger Cook, general contractor Tom Silva, and plumbing and heating expert Richard Trethewey ask, "What is it?" Afterward, Richard helps a homeowner install a new water heater with an electronic valve that prevents floods due to water leaks.

In the first episode of a two-part road trip through America's heartland, landscaping contractor Roger Cook helps a homeowner in Wichita, Kansas plant a narrow garden bed near her driveway. Then, plumbing and heating expert Richard Trethewey, general contractor Tom Silva, and host Kevin O'Connor conduct home improvement workshops with live audiences in Memphis, Tennessee, Little Rock, Arkansas, and Tulsa, Oklahoma. Afterward, Richard and a local contractor make an old fireplace more energy efficient by installing a wood-burning insert.

The conclusion of the road trip through America's heartland. Included: installing an outdoor electrical outlet; planting flower bulbs; replacing worn-out kitchen-cabinet hardware. Also: a tour of Elvis Presley's Graceland estate in Memphis.

Installing a solar water-heating system; replacing rotting support posts under a backyard deck. Also: devices that make residential electrical systems safer.

Host Kevin O'Connor and general contractor Tom Silva demonstrate how to select and install antique and reproduction door hardware. Then, Kevin and Tom, along with plumbing and heating expert Richard Trethewey and landscaping contractor Roger Cook ask, "What is it?" Afterward, Richard shows a homeowner how a geothermal home heating and cooling system works.

Landscaping contractor Roger Cook and host Kevin O'Connor show some different methods and tools for splitting firewood. Then, back in the workshop, professional painter Jeff Young shows Kevin how to choose, use, and care for paintbrushes. Then Kevin and Roger, along with general contractor Tom Silva and plumbing and heating expert Richard Trethewey ask, "What is it?" Then Richard uses an electric pump to connect a basement bar sink to a sewer drain.

Up in the workshop, general contractor Tom Silva and host Kevin O'Connor build a tool storage cabinet, perfect for any basement or garage. Then, Tom and Kevin, along with landscaping contractor Roger Cook and plumbing and heating expert Richard Trethewey ask, "What is it?" Then Kevin works with a damage prevention specialist to protect a house from catastrophic floods.

General contractor Tom Silva helps a homeowner remove a vinyl kitchen floor. Then host Kevin O'Connor tours a well-stocked architectural salvage yard for vintage house parts. Back in the workshop, Kevin and Tom, along with landscaping contractor Roger Cook and plumbing and heating expert Richard Trethewey ask, "What is it?" Afterward, Richard helps a homeowner eliminate a gurgling sound coming from his bathroom plumbing.

Landscaping contractor Roger Cook and host Kevin O'Connor head outside to do some yard clean-up using rakes, blowers and lawn vacuums. Then, up in the loft, plumbing and heating expert Richard Trethewey shows Kevin how HVAC thermostat technology has evolved over the years. Next, general contractor Tom Silva and Kevin install carpet tiles over a concrete basement floor.