Frozen Water Pipes and How to Prevent Them
- October 5, 2015 /
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The addition of requisite sprinkler pipes to MD residences has been debated on its pro’s and con’s. One thing for certain is the fact that a broken pipe in the attic, or anywhere else for that matter, can be catastrophic to the home. One reason it is a good idea to perform a comprehensive audit is that the auditor is able to identify if sprinkler pipes exist and how to properly treat them.
Water freezes at 32ºF and when it freezes it expands as anyone who has frozen a water bottle knows because the bottle puffs out on the bottom. When this freezeing occurs in your water pipes, the pipe expands which can crack the pipe or break the seal at a connection point. Typically, the water pipe still has a lot of pressure behind it and some unfronzen water somewhere in the line; so once the crack forms, water pours out of the hole until someone shuts off the water main. It only takes a minute or two for a tremedous amount of water to come out of the cracked hole and depending on where in the house the pipe burst significant property damage can occur.
So the key is to keep the water pipes above 32ºF at all times. Most water service whether from a well or from a municipality comes from the source around ground temperature of about 50ºF even in the winter which is well above the freezing point. In most homes, the bulk of the water pipes are located in interior floor joists or wall cavities that stay close to the indoor air temperature which is about 70ºF which again, is well above the freezing point. But unfortunately, many times one or two sections of water pipe can be located in an unheated basement/crawlspace, in an exterior wall or cantilever, or in the attic where they can be exposed to outside air temperatures that drop well below 32ºF in the winter. These are the pipes most susceptible to freezing.
How do you keep the cold outside air away from the water pipes? Simple, through a mixture of air sealing, insulation, and heat. There are many products available to acheive this goal, but most of the time the wrong method is chosen or installed wrong and can often make the matter worse. Identifying the right way for your home can be tricky to determine, and that is when it is best to have a trained home energy auditor evaluate your problem, but here are the basic methods.
- Insulate on the Cold side of the Water Pipe but not on the Warm Side of the Pipe – When available this is the best method because it will work forever as long as the heat is on in the house in the winter time.
- Insulate the Water Pipe Directly – In some situations this method works great, but in other situations doing this can actually cause the pipe the freeze when it otherwise would not have.
- Install a Heat Trace Wire the Length of the Pipe – This is the least preferred method because it requires constant energy usage in the winter and can potentially fail either by negligence or electrical failure.
The most important detail is to make the Sprinkler and its pipe a part of the conditioned space which will keep the water above freezing temperature at all times!