Why the garage matters

Attached garages are unheated in most Denver homes, and their walls are often less insulated than the rest of the house. Plumbing on a garage wall depends on heat leaking through from the house and on the garage door staying shut. A door left open even a little, or a gap at the bottom seal, can let in enough cold to freeze those lines during a hard cold snap.

Owners who move laundry to a garage during a remodel may not realize they have created a winter risk. The same goes for a water softener or a utility sink placed there.

The situation

Illustrative example. Not a real job or customer.

In a hypothetical 1950s ranch in southwest Denver, the washer hookups and a utility sink sit on the wall between the attached garage and the kitchen. The owners leave for a week during the holidays. A family member who has been visiting leaves the garage door open a few inches to let air in after a project.

  1. A cold front arrives the next day and holds for several nights. The washer's supply lines and the utility sink pipe freeze.
  2. The cold water line to the washer splits at a fitting inside the wall.
  3. The weather warms. Water flows into the wall, across the garage floor, and under the door into the kitchen, soaking the base of the cabinets and the vinyl floor.
  4. A neighbor notices water running out under the garage door and calls the owners, who talk the neighbor through finding the main shutoff.
  5. The owners return early. A plumber repairs the line and suggests insulating that wall and adding heat or relocating the hookups.
  6. The drying contractor lifts the vinyl flooring near the garage door, removes cabinet toe kicks to dry beneath, and opens the drywall on the garage side of the shared wall.

The garage floor dries quickly, but the kitchen cabinets and subfloor take longer. A lower cabinet with a swollen particleboard base is replaced. The owners later move the washer hookups inside and keep the garage door closed in winter.

What to decide for a garage with plumbing

  • IfLaundry or a sink is on an exterior or garage wallThenAsk a plumber about insulation, heat or relocating lines.
  • IfYou will be away in winterThenShut off water to the washer or the whole house and make sure the garage door is closed and sealed.
  • IfThe garage door seal is wornThenReplace it before winter; drafts at the floor freeze low pipes first.
  • IfA water heater sits in the garageThenAsk whether its supply lines and any recirculation lines need protection.

Lessons from this scenario

General information for Denver, not a quote or professional advice. In an emergency, call 911.