Installing a new type of water softener; a home organization app; building a shadow box using wood from an old door.

A young fan learns how to build a tool box; installing smart smoke and carbon monoxide detectors; diagnosing a leaking safety valve and installing an expansion tank to fix it.

How to install a backsplash. Also: a wireless leak detector that prevents floods; and a water feature that collects and reuses rainwater.

Reseeding a dead section of lawn and blending it in with the rest of the yard; the basics of changing a toilet; and an off-grid home tests commercial HVAC equipment.

Replacing a small radiator with one that's the correct size; and repointing brick. Also: the importance of sunscreen on the jobsite.

The differences between water filters; and different ways to locate studs in a wall. Also: removing a tree that's leaning toward a house; and installing a smart garage door opener.

A toy box is built; and the guys exchange gifts. Also: preventing fires from holiday decorations.

Roger teaches how to care for orchids; Tom fixes a window that was not hung properly and his now letting air in; Mark demonstrates how to clean brick with acid; in Future House, Ross finds a solar panel that can generate drinking water.

Roger shows how to repair a damaged walkway, and also how to identify what caused the damage so it can be prevented; Tom patches a chipped wood floor using a Dutchman and hand tools.

Mark tests out different tools that collect silica dust more efficiently; Richard shims a wobbly toilet; Kevin heads to the Catskills to build a wooden slice table with Jimmy Diresta, a maker who's famous online for his how-to videos.

Richard heads to Milwaukee to install an instantaneous water heater; Tom demonstrates some techniques for cutting straight edges with a circular saw; Mark rebuilds a retaining wall that was stacked with the wrong material.

Richard shows Kevin the proper way to ventilate a sink; in Nashville, Tom converts a regular door into a Dutch door; Jenn updates a landscape by moving around, dividing, and pruning the current plants in the yard.

Roger installs a downspout alternative; painter Mauro Henrique explains the differences between various types of paintbrushes; Richard installs a vanity for homeowners who gave up on it 7 years ago; Tom shows closet storage options.

Roger tends to a lawn that was seeded in the summer and is not doing well; Richard goes over low-budget kitchen upgrades; Tom travels to a futuristic workshop in San Francisco to build a stool using computer-based tools.

Richard diagnoses and repairs a water system with air in it; in Open House, Tom analyzes a staircase that is not to code; Mauro makes his first house call to teach a homeowner the basics of painting a room.

In this special episode of AskTOH, the guys head to Texas in the aftermath of Hurricane Harvey to profile nonprofits working to tear down, clean out, and rebuild homes that were destroyed during the storm.

Richard demonstrates a solution for replacing a water main shutoff; Jenn travels to Tennessee to build a planter out of an animal feeding trough; Mark waterproofs brick; Kevin heads back to Jimmy DiResta's shop to build a sign.

Richard discusses the possible causes and solutions for a frozen air conditioner; Tom fixes an end cap on a stair railing that is loose; Ross travels to Napa to tour a house that's testing a variety of interconnected smart home devices.

In Nashville, Richard repairs and replaces a leaking shower valve; Roger explains safety features built into all chainsaws; Kevin makes a bucket stool with Ben Uyeda, a maker best known for his design-based online videos.

Mauro teaches a homeowner how to paint a metal door; Mark explains how to match mortar for repointing jobs; Tom teaches apprentice Austin how to make a variety of different wood joints by building simple utility boxes.

Tom installs an alternative to a gutter when a traditional one does not work; Ross and Richard update Kevin on a Future House technology; Jenn heads to Phoenix to recreate the desert in a homeowner's front yard.

Mauro travels to Sacramento to show a homeowner the safe way to strip paint; Tom explains basic chiseling techniques; Richard helps a special homeowner hook up her refrigerator with an icemaker.

Mark teaches apprentice Krysten how to reface a granite fireplace; Jenn gives some tips on starting an organic garden; Richard helps a homeowner replace her kitchen faucet when she realizes her shutoff valve is broken.

Tom uses multiple techniques to make a drafty door weathertight; Mauro demonstrates the most effective way to clean a paintbrush; Roger and Jenn test out a variety of battery operated lawn tools.

In Austin, Ross visits a community that plans to have all net zero energy housing; Richard demonstrates the uses of less common wrenches; Tom and Kevin build a console table using a maple slab with a live edge on it.