Q: Last week, the pipes under my house froze at the kitchen sink. The kitchen is on the south side of the home, so we did not take any precautions and were caught unaware. I have always heard that you have to concentrate on the pipes on the north side of the home because that's where the cold air comes from. My husband took a hair dryer under the home to warm the pipes, but it took a long, long time. What can we do to prevent this from happening again? D.L., Evansville, Ind.
A: Fortunately, no one attempted to use a torch to thaw the pipes. Pay a plumber to make the repairs if all you have is a torch that could burn the house down. Your husband is also lucky that he was not injured or shocked in the crawl space. The hair dryer has a built-in ground fault circuit interrupter (GFCI) plug to protect the user from an accidental electrical shock. However, I'm sure your husband had to use an extension cord that was plugged into a wall outlet.
There is no GFCI protection for the extension cord. Any time you are in a damp or wet area, you must use a GFCI outlet or a GFCI-protected circuit for all electrical equipment.
As you have discovered, the cold air came out of the south and west during the recent cold spell. The cold air came through either the foundation vents or through the uninsulated floor or wall system.
There are several simple remedies to keep water pipes from freezing, plus a few that can be costly. Pick one or more that works for you:
- Leave the cabinet doors under the kitchen sink open so that the room air can warm the pipes.
- Place a lamp with a 60-watt bulb under the sink to warm the walls and pipes. Make sure there are no combustible materials near the bulb.
- Open the cold water tap and let the water run at a trickle to keep the water in the pipes moving.
- Close and seal, with rigid foam insulation, all foundation vents that are near water pipes.
- Insulate the foundation walls and the ends of the floor joists with rigid foam insulation.
- If the crawl access is inside the home, set a fan in the opening to blow warm air from the home to the foundation. Do not use a fan when the access is in an unheated garage or outside the home.
- If the water pipes are freezing inside the exterior wall, cut an opening in the wall to expose the pipes to the home's warm air. Place fiberglass insulation behind the pipes, between the pipes and the home's exterior wall. The hole in the wall can be covered later with a hinged door or a panel that can be removed during cold spells.
- Have the home's exterior walls insulated. Caulk and seal around doors, windows, house faucets and outside outlets.
The idea is to prevent cold air from entering or to warm the area where cold air cannot be stopped from entering. After the pipes are thawed, check for pinhole leaks or cracked pipes that can cause serious water damage to the home.
Dwight Barnett is a certified master inspector with the American Society of Home Inspectors. Write to him with home-improvement questions at C. Dwight Barnett, or write to PO Box 268, Evansville, IN 47702 or send him e-mail at d.barnett@insightbb.com.
