Have you been following the lively plumbing design discussions on ASPE Connect? In this new regular feature on ASPE Pipeline, we will highlight current discussion threads that are generating a lot of interest in the community. Also, at the end you will find some questions that need advice. Can you help?
Due to the recent extreme weather in the South, Andrew Hamilton, Project Manager with Romine Romine & Burgess Inc. in Fort Worth, Texas asked:
As you know, Texas was hit with a major winter storm that caused fire protection and domestic water pipes to burst in homes and commercial businesses. What are some ways to prevent this from happening in the future? How do my colleagues who design buildings in the northern portion of the United States design their systems to withstand the bitter cold weather?
Advice on Preventing Pipes from Freezing
According to our experts, the basic rules of thumb to prevent pipes from freezing are:
- Do not run water piping in the attic.
- Always insulate your pipes.
- Do not run piping in exterior walls.
- Add extra frost depth for parking lots, roads, and paved areas, and verify that the piping has proper cover.
If you cannot avoid running water piping in areas subject to freezing, such as attics and crawlspaces, install thermostatically controlled heat tracing wrapped in insulation on the piping.
You should consult with the architects and builders to ensure that the building openings are sealed properly and that the insulation is adequate and installed correctly. If possible, do not install insulated piping in areas where it could be easily damaged (garage stackers, mechanical areas that require frequent maintenance, etc.).
The water service must have sufficient burial depth to be below the frost line. The water service should come up on the interior of the building, not exposed on the exterior of the building.
If it is not possible to install water pipes below the frost line, such as with some storm drains from catch basins, put 6 inches of styrofoam 3 feet wide over the top of the pipe before backfilling and tamping.
Regarding fire protection pipes, NFPA requires all fire protection systems to be protected from temperatures below 40°F. Draining wet systems and placing a fire watch, while cumbersome and costly, is preferable to a frozen system or a system that won’t function properly. Dry-pipe and preaction systems with tank-mounted air or nitrogen pneumatic supplies located in a mechanical room that has either emergency heat or temporary heat can withstand low temperatures for long periods.
Finally, where power loss might result in freezing, your designs should require all water systems to be drainable. Provide the owner with instructions on how to shut down their system should they ever face an extended power loss and potential freeze-up. Also, simply opening drain valves and outlets, even if the system is not fully drained, will help minimize the number of burst pipes.
Do you want to learn more expert advice or chime in on this issue? Visit ASPE Connect now!
Can You Help?
Click on the following if you can offer some expert advice.
- Are you aware of published studies with regard to the hygiene effectiveness of 0.35 gpm faucets versus 0.5 gpm?
- What are your thoughts on conserving water by compressing air bubbles in water supply pipes?
- Is it acceptable to have an exterior drainage system routed under a building foundation?
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