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| Build It to Code to Minimize Damage from Frozen Water Pipes The 2012 International Residential Code is a guide for the design of piping for freeze protection and is coordinated with the International Plumbing Code. The winter of 2013–2014 will be well remembered for extreme record-setting cold, above normal snowfall, ice storms and water pipe damage. With temperatures plunging to single digits across the South, freezing temperatures in the Northwest and way below zero in other areas that are used to cold winters, frozen pipes and the problems they cause have kept many contractors busy. Given these challenging weather conditions, this article provides International Code Council (ICC) Members—especially code officials, building inspectors and contractors—a brief refresher on 2012 International Residential Code (IRC) requirements related to pipe freezing so steps can be taken to minimize the chances of cold weather taking its toll on pipes. When water freezes within piping, it not only prevents the flow of water, it can damage pipes, fittings and fixtures. According to the Insurance Institute for Business and Home Safety (IBHS), repair costs resulting from piping damaged by freezing costs more than $5,000, on average, for a home. Total costs are often much more when considering loss of use, repairs to water-damage to the home and the replacement of damaged contents. Therefore, providing protection for water piping and sanitary drainage piping against freezing temperature conditions, in accordance with the Section P2603.5 of the code, is of critical importance. The IRC takes a realistic approach to the need for protecting water, soil or waste piping from damage due to freezing. Piping conveying water or wastewater in uninsulated spaces like attics, crawl spaces and outside walls may be vulnerable to freezing, especially if there are cracks or openings that allow cold, outside air to flow across the pipes. Ideally, in geographic areas where there is a high probability that freezing outdoor temperatures will occur, piping should not be installed within exterior walls or in unconditioned spaces. However, the IRC recognizes that such piping arrangements are not always possible and allows for piping to be protected from freezing by insulation, heat or both. So how do building inspectors know if there is a high probability that outdoor freezing temperatures will occur? Section P2603.6 directs the reader to Table R301.2 (1), a table that is filled in by the jurisdiction upon adoption of the IRC. The column for Winter Design Temperature is a good indicator to determine whether the outside of the home will have a high probability to be exposed to freezing temperatures. Note that Winter Design Temperature is based on Appendix D of the International Plumbing Code, which lists minimum winter temperatures that have a 97.5 percent probability of occurring for the city indicated. This doesn't mean that colder temperatures will not occur. In fact, there is a 2.5 percent probability that a colder temperature will occur. And, even though the Winter Design Temperature is listed for a chosen city, outlying areas, especially in regions with significant variations in elevations, the 97.5 percent Winter Design Temperature can be much less than indicated in R301.2(1). Ultimately, the building official makes the determination on the extent of freeze protection necessary based on his/her experiences, the experiences of others familiar with the area, the type of construction and the consistency of recent low temperatures in specific localities. In areas where freezing conditions are common, inspectors and contractors have long been accustomed to the necessary measures for protecting pipes from freezing. However, in other areas that rarely experience freezing conditions piping is less likely to be adequately protected from freezing. Unusually cold temperatures can and do cause failures in these unprotected or under-protected pipes. Generally, freezing of unprotected pipes begins to occur when outdoor temperatures drop to 20 degrees Fahrenheit (-7 degrees Celsius), according to IBHS. The actual temperatures in an unconditioned space and the amount of insulation or heat required to protect piping will vary with the location of the pipe, the type of piping and the type of construction, according IBHS's Guide on Freezing and Bursting Pipes. IBHS notes that ice forming in a pipe does not typically cause a break where the ice blockage occurs. The radial expansion of ice against the wall of the pipe usually does not cause the pipe to fail. Instead, after a complete ice blockage forms in the pipe, continued freezing and length expansion of the frozen slug inside the pipe causes the water pressure to increase between the ice blockage and a closed faucet or another ice blockage. It is this increase in water pressure that leads to pipe failure. Because of this, the pipe often bursts where little or no ice has formed. Where there are not any check valves or backflow prevention devices, pressure increases upstream from an ice blockage are absorbed by the source of the water supply to the system. Sometimes piping in outside walls or in unconditioned spaces can be protected adequately by placement within the building's thermal envelope insulation. In colder climates, insulation on the pipe itself and/or a heat source such as a piping-compatible electric heating tape may be needed. The IPC Commentary states, "there must always be a heat source along with an appropriate insulation thickness in order to protect pipes from freezing conditions. Insulation itself (without a heat source) cannot protect a pipe from freezing; insulation only slows the rate of heat loss." Air sealing of is also an important measure to prevent cold outdoor air from coming in direct contact with piping.  In accordance with IRC Section P2603.5, water piping that is located outdoors and underground, must be buried not less than 12 inches (305 mm) deep and not less than 6 inches (152 mm) below the frost line depth which is also indicated by the jurisdiction in Table R301.2(1). However, local conditions might require a deeper burial depth because of soil types and locality-specific frost line depth. Such requirements are usually written in amendments made to the code by local jurisdictions. Section P2903.10 covers freeze protection for hose bibbs (including the "frost-proof" types) subject to freezing temperatures. The water supply to these hose bibbs must be equipped with an accessible stop-and-waste type valve inside the building so that the water supply can be shut off and water drained from the hose bibb during cold periods. This section includes an exception for frost-proof hose bibbs installed such that the stem extends through the building insulation into heated or semi-conditioned space, as shown below in Figure P2903.10 from the 2012 IRC.The location of backflow devices that are subject to freezing is also of concern. In accordance with Section P2902.6 of the IRC, such devices must not be located in areas subject to freezing except where the devices can be removed by means of unions (and stored in a heated area), or are protected by heat, insulation or both. If outdoor enclosures for backflow devices are used to protect backflow devices that must remain in service, those enclosures must comply with ASSE 1060, Performance Requirements for Outdoor Enclosures for Fluid Conveying Components. Dry-Type Pendent Sprinkler  Freeze protection must also be considered for buildings fire sprinkler systems, especially where piping is installed in unconditioned spaces such as unheated attics. Where sprinklers are required in areas that are subject to freezing, IRC Section P2904.2.3 requires dry-side wall or dry pendent sprinklers extending from an area not subject to freezing to the area be protected by the sprinkler. NFPA 13D also contains detailed requirements for insulation methods for protecting sprinkler system piping for outdoor temperatures as low as minus 40 degrees Fahrenheit.IRC Section P2904.1 does not allow residential fire sprinkler systems that contain an antifreeze solution, preventing that method of freeze protection. While NFPA 13D does allow the use of anti-freeze solutions, it also requires those solutions to be listed. Some types and concentrations of anti-freeze solutions are flammable and can accelerate a fire instead of extinguishing it. At the time of writing, there are not any listed anti-freeze products available, thus preventing the use of antifreeze in sprinkler systems under NFPA 13D. Finally, a word about thawing frozen piping, which is not addressed by code. Where ice blockages form, it is important to immediately shut off the water supply to the piping and follow the pipe manufacturers' guidance for corrective action for the type of pipe and fittings used. Consider resources such as the Plastic Pipe and Fitting Association's User Bulletin 10–12, Thawing Thermoplastic Pipes or the Design Guide—Residential PEX Water Supply Plumbing Systems, produced by PPI, PPFA, ICC-ES and the Home Innovations Laboratory. Open flames should never be used to thaw piping. After thawing and inspecting piping for any damage that may have resulted, the installation should be inspected to determine the cause of the failure. Repairs should comply with both applicable codes and manufacturers installation instructions. With careful adherence to the code, a solid knowledge of local conditions, and quality installation, homes built to the latest residential codes should be adequately protected against most outdoor freezing temperatures. And as technology changes so will the International Codes. Want to learn more? Check out the resources listed for even more information on pipe freezing: • 2012 International Plumbing Code and Commentary • Guide on Freezing and Bursting Pipes (IBHS) • User Bulletin 10–12 Thawing Thermoplastic Pipes (PPFA) • Design Guide—Residential PEX Water Supply Plumbing Systems (ICC, PPFA, PPI, Home Innovations Laboratory) |
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Committee Meetings Scheduled Leading Up to Group C Hearings Three ICC Technical Committees will hold meetings leading up to the Group C Committee Action Hearings in Memphis, Tenn. The purpose of the meetings is for committee members to review proposed changes to the International Green Construction Code and to identify possible changes for the 2015 Group A code cycle. |
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ICC Seeking Volunteers to Serve On Committees for the 2015–2017 Code Cycle ICC is seeking volunteers to serve on Code Committees, the Code Correlation Committee and Code Interpretation Committees for the 2015–2017 Code Development Cycle. Both new and veteran committee members must complete an application. Applications for committee service are due by June 2. Click here to apply. |
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NAHB Issues Call for Committee, Accepts Proposed Changes to ICC 700 The International Code Council is encouraging Members and stakeholders to participate in the update process for the 2015 National Green Building Standard ICC 700 by serving on the Committee & Task Group and/or submitting proposed changes. The Code Council reimburses travel expenses for Governmental Members chosen to represent the association on this committee. All other Members are responsible for their travel expenses. March 6 is the deadline for Consensus Committee and Task Group applications. March 24 is the deadline for proposed changes to the existing standard. Click here to volunteer for the committee, access proposed change forms and for more information. |
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Public Comments Requested on ICC 600 and ASABE/ICC 802-201 Standards The ICC Consensus Committee on Residential Construction in High-Wind Regions (IS-RHW) has held one public meeting to develop the third public comments draft of the ICC 600-2013 Standard for Residential Construction in High-Wind Regions. Public comments are requested on this third draft. The deadline is March 9. |
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