Season 23 - Ask This Old House

Ross Trethewey investigates a homeowner's excessive winter dry air issue and solves it by installing a whole house humidifier system; Mauro Henrique often has to paint up to 80 shutters at a time on a job, so he shares his technique for quickly painting shutters in bulk; In Build It, Tom Silva and Kevin O'Connor create a triangular top outdoor end table out of teak wood.

Kevin O'Connor teams up with wallpaper expert, Carmen Gonzalez, to help a Miami homeowner create a focal point wall with a grass cloth wallpaper; Lee Gilliam demonstrates a variety of common sprinkler heads and explains their different purposes; Richard Trethewey installs a submersible sump pump as a solution to a homeowner's flooded basement problem.

Jenn Nawada demonstrates two different solutions to solve a homeowner's gutter runoff problem by installing a dry well and a popup emitter; Ask This Old House spotlights lead carpenter Lasana Harper, who shares his journey into carpentry and how it has shaped his love for teaching; Heath Eastman helps a homeowner replace her 80's-tastic ceiling fan with a more modern option.

Nathan Gilbert transforms a homeowner's hanging bathroom medicine cabinet into a recessed medicine cabinet; Mark McCullough replaces a chimney crown that is causing water damage to a homeowner's indoor charcoal grill; Mark shows Kevin O'Connor some of the little pieces of history he's found while doing masonry work over the years.

Concrete, brick, and mortar are incredibly durable, but they’re no match for water. While on a house call, mason Mark McCullough realized the root of a homeowner's problems with their front steps was exactly that: water getting behind the stair tread, deteriorating the mortar and heaving the tread forward when it freezes. Luckily, Mark knew just what to do.

Jenn Nawada travels to her home state of Florida to assist a homeowner in choosing tropical trees for his backyard with the help of a fruit tree specialist; Nathan Gilbert demonstrates a tool that makes asphalt roof work easier; Ross Trethewey shares some home smart light products on the market today, demonstrating uses with smart light switches, smart bulbs, and strip lights that react to sound.

Mauro Henrique demonstrates how to repair cracked drywall; the team tries to guess the correct use of Tom Silva's black inflatable square; Mark McCullough walks through the evolution of bricks; Richard Trethewey shows a homeowner two different types of covers to upgrade his radiator baseboards.

Richard Trethewey and Nathan Gilbert assist a homeowner with a couple upgrades to make her bathroom better suited for aging in place; After being denied by gutter companies and local handymen, a homeowner's last hope is to call Tom Silva and Nathan to help replace her rotten wooden gutters.