Water is a unique substance. As with most materials, when water cools, its density increases and it settles to the bottom of a container. However, at 32º F, it expands and, therefore, its density decreases! This is why ice floats. This expansion increases the volume of water by about 11% and creates tremendous pressure on its container (between 50,000 and 114,000 psi). Such containers include metal and plastic pipes. No matter the strength of a material, expanding water will cause it to break.
Pipes are especially vulnerable to damage caused by expanding water. Water lines that freeze are usually those directly exposed to severe cold, such as outdoor hose bibs, swimming pool supply lines, or water sprinkler lines. In addition, pipes in unheated interior areas such as basements, crawl spaces, attics, garages, and kitchen cabinets, and those that run against exterior walls with little or no insulation are also susceptible to freezing.
A number of variables contribute to freeze damage: the type of building construction; the quality and quantity of insulation; the decline in temperature; the direction and force of wind; and other weather-related conditions are all contributing factors.
Buildings that are poorly designed and do not withstand severe weather sufficiently can contribute to their own damage. The type and age of the plumbing system is also a factor. Rust or corrosion weakens pipes, making leaks more likely to occur. When freeze-expansion occurs, corroded pipes will often split open. When thawing begins or when the water is turned back on, damage can occur.
During renovation of older homes, blown-in or foam insulation is sometimes added to wall cavities between interior and exterior wall surfaces and between studs. This process may actually insulate heat away from pipes adjacent to the exterior wall surfaces, making them more susceptible to freezing.
Surprisingly, pipe freezing can be a particular problem in the warmer climates of southern states. In these areas, buildings may not be adequately constructed for cold weather conditions. Pipes often run through non-insulated or under-insulated attics, crawl spaces, or walls. If the temperature drops below freezing for even a day, these pipes may freeze and break.
In northern climates, many people go south for the winter. They “winterize” their homes by draining the plumbing system and adding antifreeze to plumbing fixtures. This is an excellent prevention procedure and greatly reduces the possibility of frozen pipes.
Draining of a plumbing system should be thorough and complete. If water lines sag or bow, there may be low spots that are difficult to drain completely. To be most effective, compressed air should be used to blow out the lines. If not properly done, some amount of water will remain in the low points of the lines that can freeze.
Damage generally occurs when the water supply is turned back on. Since most modern plumbing lines are inside walls hidden from sight, a freeze-caused leak is usually discovered only after water has damaged floors, carpet, walls, or ceilings. Occasionally, an occupant hears the sound of spraying water, but by then it may be too late. The leak has already caused some degree of damage.
Winter wind, snow, and ice storms frequently damage electric power lines and equipment, resulting in interruptions of electric power. Most heating systems depend on electricity, and when the power goes off, so does the heat. In severe cold weather, this can result in extensive freeze damage before power is restored.
Following are some tips to help prevent damage from frozen pipes when away from your home for more than a day or two:
1. Shut off the water supply and drain pipes or appliances.
2. Have someone you trust check your home about once per week if you are away.
3. Have emergency numbers handy such as a plumber, electrician, roofer, and PuroClean in case something does go wrong.
4. Protect pipes, fittings, and appliances against freezing with insulation or heat strips.
5. Have your HVAC system serviced before leaving if you will be away for an extended period of time.
6. Set your thermostat no lower than 55 degrees.
7. Before leaving turn off your water heater. (See owner’s manual for procedures.)
8. Install storm windows and/or close shutters to keep in heat.
9. Clean gutters and downspouts to ensure proper water drainage.
10. Service sump pump to ensure proper operation. Adding a backup power source is prudent.
11. Unplug all nonessential electric appliances.
12. Inform local police if you will be out of town.
Regardless of the circumstances — frozen or leaking pipes or any water damage, fire/smoke damage, biohazard remediation or mold remediation — call your local PuroClean office, the Paramedics of Property Damage™. For all property damage situations, these professionals are standing by. They will mitigate the loss to prevent further damage and will then provide damage restoration services to return the property to a pre-loss condition as quickly as possible. All PuroClean offices have well-trained water damage restoration professionals who provide the latest state-of-the-science services to all property damaged from water, fire, smoke, mold, and other disasters.