Avoiding a Laundry Room Flood in an Upstairs Laundry Room

Prevent damage from washing machine overflows and supply hose leaks with a proper installation.

Second floor laundry rooms can create a lot of damage if the wash machine leaks. We'll show you four DIY steps to prevent a water catastrophe. You won't have to spend a lot of time or money, and you'll safeguard against an upstairs flood.

By the DIY experts of The Family Handyman Magazine

Avoid a flood in your upstairs laundry room

Washers and floods go hand in hand and can cause huge damage to the laundry room floor and the rooms below. Take these four steps to prevent a disaster if an overflow or leak occurs.

1. Install a recessed washer box (available at home centers) in the wall directly behind the washing machine. This recessed box provides connections with shutoff valves for the water supply hoses and a drain for the washer’s discharge hose. For easy access and servicing, mount the bottom of the box so it’s about level with the top of the washing machine’s control panel. Be sure to choose a box with the shutoff valves included.

2. Install a washer tray under your washing machine. Set the tray tight against the back wall framing and run the drywall down to it. Our tray’s drain does not connect directly to the house’s waste line. It’s an indirect line that dumps into a laundry tub, floor drain or even outside through the wall. If the machine leaks, the water will be caught in the tray and safely drained away. Washer trays are available at home centers.

3. Make sure the supply hoses are in good shape. Check older hoses for cracks and replace if necessary. If you’re buying new hoses, consider the no-burst ones; these rubber hoses are sheathed with braided stainless steel. Be sure to use new hose washers. Connect and hand-tighten the hoses to the supply valves and the washing machine inlet. Turn the water on and check for leaks. If necessary, tighten further either by hand or with pliers.

4. Turn off the water to the supply hoses when the washing machine is not in use for additional peace of mind. This is easy to do with a single-lever shut off such as the one shown here.

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Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

  • Hacksaw
  • Drywall saw
  • Hammer
  • Soldering torch
  • Tape measure
  • Corded drill

You'll also need a circular saw or reciprocating saw to cut into the floor. And you'll need a 1-3/4 in. or 2-1/4 in. spade bit to drill through studs to run the PVC pipe.

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

  • PVC solvent cement
  • Solder
  • Washer box
  • Water line shutoffs
  • 1-1/2 or 2 in. PVC pipe
  • Copper pipe
  • Drain assembly

You may also need new supply hoses and a new discharge hose.