“Insulating water lines does not stop them from freezing,” warns plumber Bob Beall.
The logic of insulating water lines is based on the hope that you can out wait the cold long enough for warmer temperatures to prevail–for example, says Beall, “when temperatures fall below freezing at night but rise above freezing during the day when the sun comes out.”
There are two materials that can be used to insulate water lines. Wrap them with fiberglass insulation (which rarely works very well) or snap on split-foam insulation. Those serious about insulating water lines, the snap-on foam, the thicker the better, should be used. According to the most referred plumber, “some varieties come with a peel-off backing that exposes a self-adhesive strip on the edges, sticking the edges together.” Absent the self-adhesive, duct tape must be used on the edges at intervals along its entire length.
Read the following tips and learn how to insulate your water lines:
• To start, cut the foam insulation to length and slip it onto the pipe.
• Close the seam by peeling off the protective adhesive strip and pressing the edges together or by taping the seam.
• To hand an insulated water line, use pipe hanger strapping or plastic J-hooks.
• To insulate an elbow, either cut a slit out of the pipe and slide it onto the corner or cut a diamond pattern out of the foam and slide the cutout over the elbow.
• Bonus Tip: Turning A Corner
To insulate an elbow, either cut out a triangular section of the insulation and slide the cutout to fit around the elbow, or, cut a rectangle out of a section and slide it on the elbow. Use whatever method makes it easiest to push the insulation around the elbow.
Source: Mr. Rooter