Some pipes are more prone to freezing than others because of their location in the home.  Pipes most at risk for freezing include:

  • Exposed pipes in unheated areas of the home
  • Pipes located in exterior walls
  • Any plumbing on the exterior of the home

Perhaps you just purchased a home that has undergone a bathroom renovation and the last owner installed a brand new rain shower head by running new plumbing through the ceiling (which actually is the attic of your home).  What if the attic is not properly insulated?  Is there a risk that your new shower plumbing might freeze?

Exposed Interior Plumbing

Exposed pipes in the basement are rarely in danger of freezing because they are in a heated portion of the home.  But plumbing pipes in an unheated area, such as an attic, crawl space and garage, are at risk of freezing.

Often, inexpensive foam pipe insulation is enough for moderately cold climates.  Determine the diameter of the pipes and but the correct size foam insulation.  Foam pipe insulation is sold at your local hardware store.

For severe climates, opt for wrapping problem pipes with thermostatically controlled heat tape ($50-$200 depending on length) which will turn on at certain minimum temperatures.

Under-Insulated Walls

If pipes travelling in exterior walls have frozen in the past (tell-tale signs include water damage, mould and moisture build-up), it’s probably because of inadequate or improperly installed insulation.  It might well be worth the couple hundred dollars it costs to open up the wall and beef up the insulation.  Make sure you keep the fiberglass batt insulation on the cold side and no insulation on the warm side.  This keeps the pipes toward the warmest side.  You may want to consider running that pipe in PEX as it tends to be very forgiving if it freezes and not split like other pipes.  The PEX tubing has some stretch built into it.

Wrap-on pipe heating cables prevent frozen water pipes to -40f and are engineered for use on metal and rigid plastic pipes.  Most of these types of cables have a built in thermostat that turns the cable on at 38f with a power sensor light that glows when it’s on.

When nothing else works, for example a northern wall in a really cold climate, the last resort is to reroute the pipe.  Depending on how far the pipe needs to be moved, and how much damage is caused in the process, this preventative measure costs $700 or more.  Putting the room back together is extra.

In summary, keep in mind that when your plumbing is in an unheated space, it really comes down to proper insulation of the exterior wall/ceiling/attic, etc. or the pipe itself.

For more information on how to safely thaw a frozen pipe, click here.