With autumn in full swing and winter on the horizon, low temperatures begin to pose a danger to plumbing systems. Every year, frozen pipes and ensuing water damages result in insurance claims ranging from a few thousand dollars in homeowners and personal lines losses to multi-million dollar losses in the case of commercial buildings, high rises and buildings under construction.
Uninsulated pipes routed through unheated areas such as crawl spaces, basements, and attics are at the greatest risk where the ambient temperatures can drop below freezing. Common knowledge of the expansion of water as it solidifies into ice suggests that a pipe would burst where an ice plug forms. Instead, it is usually downstream as a result of the increased pressure of liquid water trapped between the ice plug and the nearest valve, such as a faucet.
Once the temperatures drop below freezing ice begins to form on the inner surface of a pipe, slowly reducing the area for water to flow through. At this point, you may notice reduced water flow from the fixtures within a building such as faucets and showerheads.
When the ice plug grows the entire cross-section of the pipe, the downstream water becomes trapped between the plug and the nearest valve. It is well known that when water turns to ice, it expands by roughly 9%. As the ice continues to form, this expansion causes a pressure rise in the trapped water that can eventually induce stresses in the pipe wall that is greater than the strength of the pipe material resulting in a burst.
At first, only the trapped liquid water escapes through the burst. If the burst is discovered at this stage then there is a good likelihood of repairing it before significant water loss occurs. Unfortunately, if the ice thaws before the burst is found, then the water supply is free to flow out of the pipe and soak everything around it. This is especially dangerous to those leaving their homes unattended for long periods of time in the winter.
Outfits such as House Logic, Family Handyman, Popular Mechanics, and the American Red Cross cover the possible steps to minimize the chances of a burst pipe due to freezing. Common ones are summarized as follows:
- Drain outdoor hose spigots by closing the interior valves and opening the spigot. Leave the spigots open
- Make sure the hoses are disconnected
- Insulate attics, basements, and crawl spaces
- This will help in retaining heat in these spaces
- Insulate exposed pipes with foam insulation
- Alternatively, use electric pipe heaters
- Let the fixtures served by exposed piping drip in freezing conditions
- This leaves an opening for the liquid water to escape from if the pipe freezes thus limiting the likelihood of a burst
- Open cabinet doors such as underneath sinks to circulate the warm indoor air
- Maintain a nighttime thermostat setting the same as daytime
- Do not set the thermostat below 55˚F when leaving a home for extended periods
- It also helps to close the main building supply and drain the entire house plumbing by opening all fixtures
If you suspect a frozen pipe or experience low water pressure, the best course of action is to call a licensed plumber who will address the issue. Remember to check your plumbing system and follow the outlined suggestions to minimize the risk of serious damage due to a frozen pipe. Let this winter pass with nothing more than a few beads of sweat shoveling the snow.
About the Authors
Al Fafara is a highly experienced examiner, adjuster, and supervisors in property, energy, and construction risk claims with over 35 years of handling large, complex losses. Often these involved multiple markets and involved analyzing sophisticated policy wordings, investigations as to cause and damages and the pursuit of subrogation recoveries. Al is presently with RTI Forensics as the Director of Insurance Claims Consulting. He is responsible for business development and growth with the property and casualty claims industry.
Aleksey Galkin is a mechanical engineer practicing in the field of forensics. Throughout his employment at RTI, he has participated in a wide variety of accident investigations. Some notable ones include failures of aviation flight critical components both of mechanical and electrical in nature, failures of electrical power generation and distribution systems, fires, explosions, and water damage to commercial and residential buildings, personal injuries relating to construction equipment and material handling as well as consumer products such as power tools, aerosol cans, and lithium batteries.