Averting Winter Water Pipe Bursts
Arvada, Colorado (December 05, 2012) – Tyler Schwein, B.S. E.I.T., Pie Consulting & Engineering (Pie), Forensic Specialist, was recently published in the November 28, 2012 online edition of PLRB – Test Your Claims Knowledge with an article titled Winter Pipe Ruptures: Was Adequate Heat Provided? Lending his mechanical analysis expertise, Tyler offers preventative steps for homeowners to keep water pipes from freezing in the cold winter months ahead.
The Principles of Frozen Pipes
The occurrence of frozen pipesis a multi-dimensional heat transfer problem. More specifically, frozen pipes are a function of temperature and time; including the exterior temperature, interior temperature, pipe location, and insulation.
The cycle “looks” like this:
- Heat within a system naturally dissipates until the system reaches the temperature of its surroundings.
- Water freezes within piping as heat from the water is transferred to the colder air.
- Water expands as it freezes and eventually forms a blockage within the pipe as it solidifies.
- Continued expansion of ice buildup increases the water pressure in the system.
- Pipes rupture ultimately causing leakage or flooding in the home. Depending on the size of the fracture, a ruptured supply pipe can leak as much as 10,000 gallons of water per day.
- Insulate, insulate, insulate! Apply adequate insulation or heat tape to exposed pipes (crawlspaces, attics, garages).
- During prolonged periods of extremely cold temperatures, open vanity cabinet doors along the exterior walls – this allows warmer interior air to reach the piping.
- Allow water to trickle from the faucets for two reasons: 1), to relieve pressure buildup in the event water begins to freeze within a pipe and 2), to prevent freezing by drawing in relatively warmer water to replenish the system (depending on the volume of the trickle).
“Diagnosing freeze damage in piping assemblies is relatively straightforward because the failure occurs at the weakest location. When assembled correctly, soldered copper joints are stronger than the pipe; therefore, the pipe will tend to fail along the length of the pipe. A hairline fracture extending along the axis of the pipe indicates an over-pressurization which occurs as a result of freezing. Ice buildup and expansion creates a pressure buildup of the remaining water. The resultant pressure buildup of the water will eventually exceed the pressure limits of the pipe and effectively rupture it. Additionally, inadequate joints and certain valves may be weaker than the length of the pipe, thus failures may occur at these locations as well.” – Tyler Schwein, B.S. E.I.T, Pie Consulting & Engineering.
Winterization of Vacant Homes
- Reconsider lowering your heat setting when planning to be away for extended periods of time during the winter. Note: most homeowner’s insurance policies contain coverage exemptions relating to a failure to provide “adequate heat.” This provision does not indicate a specific temperature threshold, although a minimum of 55°F is a commonly used general reference.
- Although many experts recommend a 55-degree minimum, this recommendation does not have academic origin. Every structure is unique in terms of the placement of pipes, insulation, thermostat location, and many additional factors. It is better to be safe than sorry as turning the heat down in search of the lowest possible heat setting can result in pipe freeze breaks which lead to costly repairs.
- If the heating system is going to be shut off at a vacant residence, it is imperative that the home is properly winterized. Winterization includes closing the main water supply valve to the building and purging the water from all of the water supply piping and plumbing appliances.
- Drains with P-traps should be cleared of water and filled with nontoxic antifreeze to prevent sewer gases from entering the residence.
Pie is frequently retained to evaluate pipe freeze losses and determine whether or not “adequate” heat was provided within the residence.
”The thermostat setting can easily be observed while inspecting a residence that has endured a freeze-ruptured water pipe. If the thermostat is switched “off,” then it is oftentimes a straightforward case; however, the homeowner might adjust the thermostat setting after the rupture in order to give the appearance that heat had been provided. It is also important to realize that some mercury switch thermostats can easily be adjusted out of level to lower the minimum temperature point. If the position of the thermostat is altered by rotating the wall assembly, the minimum allowable setting can be drastically reduced to a less-than-safe temperature. The most dependable method to determine whether or not heat was provided to a residence requires energy consumption calculations.” – Tyler Schwein, B.S. E.I.T, Pie Consulting & Engineering.
Claims and Potential Liability
Water leaks from frozen water pipes result in significant losses each year, second only to hurricanes in terms of both the cost of the claims and the number of damaged homes. Although some insurance companies do not officially recognize frozen water pipes as a “catastrophe”, insurers across the nation share the burden of these incredible monetary losses.
Property owners and managers may be responsible for damages that result from a pipe rupture and the subsequent leakage in an unheated (or inadequately heated) building. The resulting water damage can be extremely costly to repair when, in most cases, pipe freezing is completely preventable with winterization techniques.
About Tyler Schwein: Tyler possesses a Bachelor’s of Science degree in Engineering with a Mechanical specialty from the Colorado School of Mines. He is professionally recognized as an Engineer in Training according to the National Council of Examiners for Engineers and Surveyors. He has been extensively involved with failure analysis and laboratory testing as they pertain to mechanical engineering and claims investigation.