Appendix A — Explanatory Notes to Part 7

Combined building drains may have proven acceptable on the basis of past performance in some localities and their acceptance under this Code may be warranted.

Building sewers and water service piping serving buildings that are not located within the same property may be interconnected if the owners of the properties and the municipality enter into an agreement that is registered against the title to which it applies.

Sentence 7.1.4.1.(1) aims to help ensure that plumbing systems will remain in place for a sufficient amount of time during an earthquake to allow for the safe evacuation of the building.

One method of ensuring that the floor complies with Sentence 7.2.2.3.(1) is to use a non-ferrous sheet metal or a rubber or plastic membrane and, where the protected floor area adjoins a perimeter wall, the water stop shall be turned up at least 100 mm above the waste opening.

The use of concealed overflows does not preclude the use of a standing waste.

Centre outlet waste fitting means a drain that is equipped with a flat metal strainer at the waste inlet of a tailpiece and it is commonly known as a grid drain. Appendix A • Volume 2 Page 151

(1) Vent to be sized in accordance with Article 7.5.6.3. (2) Length A depends on trap size.

CSA B481.4, “Maintenance of grease interceptors”, is considered to represent good practice regarding procedures for the maintenance of grease interceptors.

Concrete fittings fabricated on the site from lengths of pipe may have proven acceptable on the basis of past performances in some localities and their acceptance as an alternative solution pursuant to Section 2.1. of Division C may be warranted.

Joints within the high-density polyethylene pipe (HDPE) shall be heat-fused according to the manufacturer’s instructions. Joints between HDPE pipes and other materials shall be made with a suitable hubless coupling.

There are some special installation requirements for the use of crosslinked polyethylene pipe and its associated fittings. Reference should, therefore, be made to the installation information in CAN/CSA-B137.5, “Cross-Linked Polyethylene (PEX) Tubing Systems for Pressure Applications”.

CSA B137.6, “Chlorinated polyvinylchloride (CPVC) pipe, tubing, and fittings for hot-and cold-water distribution systems,” CSA B181.1, “Acrylonitrile-butadiene-styrene (ABS) drain, waste, and vent pipe and pipe fittings,” and CSA B181.2, “Polyvinylchloride (PVC) and chlorinated polyvinylchloride (CPVC) drain, waste, and vent pipe and pipe fittings,” reference ASTM D3138, “Standard Specification for Solvent Cements for Transition Joints Between Acrylonitrile-Butadiene-Styrene (ABS) and Poly(Vinyl Chloride) (PVC) Non-Pressure Piping Components,” which specifies the colour of the solvent cement. PVC cement shall be grey, ABS cement shall be yellow, CPVC cement shall be clear and transition cement shall be white. The standard colour allows Code users to readily determine if the correct solvent cement has been used. It should be noted that a transition cement is not an all-purpose cement.

There are some special installation requirements for the use of polyethylene/aluminum/polyethylene composite pipe and fittings. Reference should, therefore, be made to the installation information in CAN/CSA-B137.9, “Polyethylene/ Aluminum/Polyethylene (PE-AL-PE) Composite Pressure Pipe Systems”. Page 152 Appendix A • Volume 2

Composite Pressure Pipe and Fittings. There are some special installation requirements for the use of crosslinked polyethylene/aluminum/crosslinked polyethylene composite pipe and fittings. Reference should, therefore, be made to the installation information in CAN/CSA-B137.10, “Crosslinked Polyethylene/Aluminum/Crosslinked Polyethylene (PEX-AL-PEX) Composite Pressure Pipe Systems”.

There are some special installation requirements for the use of polypropylene pipe and fittings. Reference should, therefore, be made to the installation information in CAN/CSA-B137.11, “Polypropylene (PP-R) Pipe and Fittings for Pressure Applications”.

It should be noted that CSA B137.18, “Polyethylene of raised temperature resistance (PE-RT) tubing systems for pressure applications,” contains special installation requirements, which should be followed.

The use of galvanized steel pipe and fittings in a water distribution system may have proven acceptable on the basis of past performance in some localities and its acceptance as an alternative solution pursuant to Section 2.1. of Division C may be warranted.

Saddle hubs or fittings may have proven acceptable on the basis of past performance in some localities and their acceptance under this Code may be warranted.

Flow restriction devices within supply fittings should not be removed. Due to the low flow rate of public lavatory faucets, design consideration should be given to the wait time for hot water to be delivered to each fixture.

Manually operated valves are also known in the industry as supply line stops.

Hot water delivered at 60°C, a typical thermostat setting for storage-type service water heaters, will severely burn human skin in 1 to 5 s. Consequently, Article 7.2.10.7. sets an upper limit on the temperature of water discharging from shower heads and into bathtubs. The water temperature is maintained at or below this limit through the installation and adjustment of automatic compensating valves or temperature-limiting devices. Compliance with the Article reduces the risk of scalding in showers and bathtubs, which could result in severe burns, and the risk of thermal shock in showers, which could lead to falls. Children, older adults and people with disabilities are particularly at risk of scalding because they are not always able to remove themselves quickly from a shower or bathtub if the water becomes too hot. At a water temperature of 49°C, the time for a scald burn to occur on is nearly10 min, whereas the time for a scald burn to occur on an older adult is only 2 min because their skin is thinner and less vascularized. At a water temperature of 43°C, scald burns occur only after several hours of exposure. Therefore, setting 43°C as the maximum temperature for water discharging from shower heads and into bathtubs provides suitable protection from scald burns in healthcare facilities and seniors' residences. Although the temperature of water discharging into other fixtures, such as lavatories, sinks, laundry trays and bidets, is not addressed by Article 7.2.10.7., a risk of scalding may nonetheless exist at such fixtures. It should be noted that pressure-balanced valves are sensitive to seasonal changes in the temperature of the cold water supply and may require adjustments throughout the year to avoid exceeding the maximum water temperature prescribed in Article 7.2.10.7. Appendix A • Volume 2 Page 153

An air admittance valve is a device that is closed by gravity and seals the vent terminal at zero differential pressure (no flow conditions) and under positive internal pressures. The valve allows air to enter the drainage system without the use of a vent extended to outside air and prevents trap siphonage. The material of the diaphragm can be damaged by exposure to acids or corrosive fumes in the ambient atmosphere; therefore, air admittance valves should not be installed in locations where there is a potential for exposure to such fumes.

Storm sewer blockage can cause mechanical joints at the base of leaders to fail, which can result in flooding. The failure occurs because the cleanout joints at the base of the rainwater leaders are not able to withstand the water column pressure. To avoid such failures, it is necessary to ensure that storm water systems installed using mechanical joints be braced and/or restrained at the ends of branches, changes in direction and elevation, at dead ends and at other locations as required by the manufacturer to prevent the separation of joints due to internal pressure, mechanical stress or seismic events. Care should be taken to replace cleanouts properly after maintenance or testing.

Expansion and contraction in piping systems may be accommodated in a number of ways including, but not limited to, piping design and layout, material selection, and the inclusion of expansion joints. Example: To determine the expansion of 20 m of ABS pipe for a temperature change from 10°C to 60°C. Temperature change is 60 – 10 = 50°C Enter the chart at 50°C, read up to the ABS line (#4), and then across to the mm scale. 47 mm/10 m of pipe therefore the change in length over 20 m is 20/10 X 47 = 94 mm Page 154 Appendix A • Volume 2

Code compliant drain, waste and vent piping of polymeric plastic having schedule 40 dimensions must be installed with select piping bedding where the fill over the pipe will be subject to vehicular traffic or where the burial depth exceeds eight feet. Sewer pipe of polymeric plastic conforming to a standard that requires a minimum pipe stiffness of 320 kPa shall be installed with select pipe bedding where the fill over the pipe will be subject to vehicular traffic or where the burial depth measured from the top of the pipe exceeds 750 mm. Select pipe bedding consists of a non-cohesive ballast material of which at least 50% will pass a ¼ inch sieve and 100% will pass a ½ inch sieve, and that completely surrounds the pipe by a radial depth of at least four inches and that is sufficiently consolidated so that the intended earth loading will not produce further compaction.

Concrete thrust blocks may be used to provide restraint for underground water service piping. They are readily utilized in combination with tie rods, structural restraining, thrust collars and restrained joints. Thrust blocks are generally categorized as gravity blocks or bearing blocks. Important factors which may affect gravity block design are pipe sizes, water pressure, density of block material and allowable soil bearing pressure that will determine the minimum size of the block base. Publications of pipe and fitting manufacturers show methods for installing thrust blocks at different fittings. In each case, the trench is cut to provide a bearing surface on undisturbed soil, and concrete is placed to fit snugly against as much of the fitting as possible without interfering with access to fitting joints. Sometimes anchor rods may be used to hold the fitting against the blocks.

Stronger pipes may be required in deep fill or under driveways, parking lots, etc., and compaction for the full depth of the trench may be necessary. Bedding is required primarily to provide uniform and adequate longitudinal support under the pipe. All drainage pipe shall be supported in such a manner as to maintain its alignment, and prevent sagging. Blocking alone shall not be used to maintain pipe grading. Bell holes at each joint shall be provided to permit the joint to be assembled properly while maintaining uniform pipe support. A compacted depth of 100 mm to 150 mm is generally sufficient bedding thickness. Ledge or sharp rocks and clods which could damage the pipe cannot be used. In general, select pipe bedding shall consist of a non-cohesive ballast material of which at least 50% will pass a ¼ inch sieve and 100% will pass a ½ inch sieve, and that completely surrounds the pipe by a radial depth of at least 100 mm and that is sufficiently consolidated so that the intended earth loading will not produce further compaction.

Piping Exposed to Freezing No water, soil, or waste pipes shall be installed on the exterior of a building or in the uninsulated side of an exterior wall, or in any place where they may be subjected to freezing temperatures, unless adequate provision is made to protect such pipes from freezing (such as applying trace wires or insulation). The Thermal Insulation Association of Canada (TIAC) “Mechanical Insulation Best Practices Guide” 2013 edition is a comprehensive source of information on the selection, installation and proper use of thermal insulation materials. (Note that Section 4 of this Guide is not included in the scope of this Appendix Note as it contains information on proprietary products, which are not within the mandate of the Code.) Insulation of Buried Piping Failures in buried pipe are caused by improper installation, corrosion, poor design, soil movement caused by freeze-thaw situations, to name some of the causes. Designing for frost protection is a consideration in Ontario because all regions experience winter conditions, where temperatures drop below freezing, and it is impractical to bury piping below the depth of frost penetration, insulation may be used to protect the pipe from freezing temperatures. Appendix A • Volume 2 Page 155 There are two methods available: (1) insulation is formed to fit around and encapsulate the pipe, or (2) a sheet of insulation at some level above the buried pipe. The type of backfill that is used to bury pipe is most important because this determines how the frost will pass through the backfill and penetrate the buried pipe. Typical Water Pipe Protection by Horizontal Insulation The width of a sheet of insulation may be calculated using the following formula: Width of Insulation: W = D + 2 (F-X) - 0.3 where: W= Width of Insulation (m) D = Outside Diameter of Pipe (m) X = Insulation Depth (m) F = Estimated Frost Depth (m) Having calculated the width of the insulation, the thickness can be found on a chart, similar to the one shown below. Thickness of Foam Insulation, mm Design Freezing Index (°C-Days) 850 1 125 1 400 1 675 1 950 2 225 2 500 0.6 50 65 75 90 100 115 125 Amount of Backfill over the 0.9 40 50 65 75 90 100 115 Insulation, m 1.2 25 40 50 65 75 90 100 1.5 25 25 40 50 65 75 90 1.8 25 25 25 40 50 65 75 2.1 25 25 40 50 65 2.4 25 25 40 50 2.7 25 25 40 3.0 25 25 Column 1 2 3 4 5 6 7 8 9 Page 156 Appendix A • Volume 2

The provisions of this Article are intended to limit the probability that failure of an in-ground building drain or building sewer would lead to the contamination of potable water in a water service pipe. Sentence (1) requires that a minimum 2 440 mm horizontal clearance be provided between a water service pipe and a building drain or a building sewer. Sentence (2) describes certain exceptions which would permit the water service pipe to be closer than 2 440 mm to the building drain or building sewer. Sentence (3) recognizes that in certain instances, the water service pipe and a building drain or building sewer may have to cross each other. In this case, the greatest risk of contamination to the potable water is through joints in the water service pipe under backflow conditions. In order to avoid this, the Code requires that there be no joints in the water service pipe within 2 440 mm horizontally of the intersection with the building drain or building sewer. The illustration below appears to meet this requirement, however it is intended that no joints in the water service line be located within 2 440 mm of the closest point on the building drain/sewer.

The addition of a non-toxic indicating substance, such as an aerosol, fluorescent dye, smoke or an odorant, to an air pressure test may help in identifying the location of a leak. However, the additive must be compatible with the piping material being tested: the intent is to identify the leak without affecting the outcome of the test or the integrity of the plumbing system. Appendix A • Volume 2 Page 157

High sudsing detergents used in clothes washers produce suds that tend to disrupt the venting action of the venting systems and can also spread through the lower portions of a multi-storey drainage system. The more turbulence, the greater the suds. One solution that avoids the creation of suds pressure zones involves connecting the suds-producing stack downstream of all other stacks and increasing the size of the horizontal building drain to achieve a greater flow of air and water. Using streamlined fittings, such as wyes, tends to reduce suds formation. Check valves or backwater valves in fixture outlet pipes have also been used to correct problem installations.

Equipment such as garbage grinders and potato peelers produce waste with organic solids. These devices reduce most waste into small particles that will flow easily through the drainage system. However, if they are located upstream of the interceptor, the particles could block the interceptor. Page 158 Appendix A • Volume 2

When the temperature of the heated discharge exceeds 75°C, the material being used shall be used in accordance with the manufacturer’s approval and done in accordance with the manufacturer’s instructions. Where the material being used is a thermoplastic, care should be taken with discharges above 55°C.

For large volume engineered interceptors, the drain down time may vary. Grease interceptors may be required when it is considered that the discharge of fats, oil or grease may impair the drainage system. Further information on the design and sizing of grease interceptors can be found in the ASPE 2012, “Plumbing Engineering Design Handbook, Volume 4, Chapter 8, Grease Interceptors”.

Chemically loaded and bio-hazardous wastes can be dangerous to private and public sewer systems and hazardous to people. The treatment of corrosive and acid waste is mandated by this Code. The treatment of chemically loaded effluents is usually regulated by sewage collecting and treatment authorities. The treatment of bio-hazardous waste should follow good engineering practice, such as that described in the Laboratory Biosafety Guidelines published by Health Canada. Bio-hazardous waste disposal systems require specific engineering expertise and remain outside the scope of this Code.

An interceptor that replaces a trap must be vented in the same way as the trap it replaces. (See Note A-7.4.2.1.(1)(a)(ii) and (e)(vi)) Where an interceptor other than an oil interceptor serves a group of fixtures requiring more than one trap, each fixture must be properly trapped and vented. (See Article 7.5.5.2. for venting of oil interceptors.)

When an untrapped leader drains to a combined building sewer, clearance requirements are the same as for vent terminals. (See also Note A-7.5.6.5.(4))

In most installations, controls will be installed in conjunction with a float to automatically empty the sump. If such controls are not provided, the capacity of the sump should equal the maximum inflow to the sump that is expected to occur during any 24 h period.

These requirements are intended to apply when, in the opinion of the local authority having jurisdiction, there is danger of backup from a public sewer.

A trap cleanout plug is not acceptable as a cleanout for the fixture drain; hence, either a separate cleanout or a trap with a removable trap dip must be installed.

To accommodate the limitations of sewer cleaning equipment, the cleanout should be located as close as possible to the exterior wall of the building, either inside or outside, and be accessible for sewer cleaning equipment.

Although slopes below 1 in 100 are permitted for pipes over NPS 4, they should be used only where necessary. Steeper slopes and higher velocities will help to keep pipes clean by moving heavier solids that might tend to clog the pipes. Appendix A • Volume 2 Page 159 A-Table 7.4.9.3. Hydraulic Loads. Bathroom Group A bathroom group is considered to consist of 1 water closet, 1 lavatory, and 1 bathtub (with or without shower head) or a shower stall. Hydraulic Loads for Laundry Traps When determining the hydraulic load on a pipe, no allowance need be made for a load from a domestic clothes washer when discharged into a laundry tray, since the hydraulic load from the laundry tray is sufficient. Hydraulic Loads for Floor Drains No hydraulic load is required from a floor drain in a washroom since it is for emergency use only.

Fixture outlet pipes that are common to 2 or 3 compartments or fixtures are sometimes referred to as continuous wastes and are not considered to be branches. (See also Note A-7.4.5.1.(2).)

Climate information on rainfall intensities for various localities is found in MMAH Supplementary Standard SB-1, “Climatic and Seismic Data”. When calculating the hydraulic load from a roof or paved surface, it should be noted that a 1 mm depth of water on 1 m2 of surface is equivalent to 1 L. A-Table 7.4.10.5. Conversion of Fixture Units. The following table expands Table 7.4.10.5.: Page 160 Appendix A • Volume 2 Maximum Probable Drainage Rate, gal/min Fixture Units Fixture Units Fixture Units Fixture Units Fixture Units Fixture Units Fixture Units Fixture Units Fixture Units Fixture Units Fixture Units Fixture Units in Service Col. 1 Col. 1 x 10 Col. 1 x 100 in Service Col. 1 Col. 1 x 10 Col. 1 x 100 in Service Col. 1 Col. 1 x 10 Col. 1 x 100 10 21 53 174 40 38 102 435 70 47 140 680 11 23 55 183 41 38 103 444 71 47 141 687 12 24 57 192 42 39 104 453 72 47 143 694 13 24 59 201 43 39 106 462 73 48 144 701 14 25 61 210 44 39 107 471 74 48 145 708 15 25 63 219 45 40 108 480 75 48 147 715 16 26 65 228 46 40 110 488 76 48 148 722 17 26 67 237 47 40 111 496 77 49 149 729 18 27 69 246 48 41 112 504 78 49 151 736 19 27 71 254 49 41 114 512 79 49 152 743 20 27 72 262 50 41 115 520 80 49 153 750 21 28 74 271 51 42 116 528 81 50 154 759 22 29 75 280 52 42 118 536 82 50 155 768 23 29 77 289 53 42 119 544 83 50 156 777 24 30 78 298 54 43 120 552 84 50 157 786 25 30 80 307 55 43 122 560 85 50 159 795 26 31 82 316 56 43 123 568 86 51 160 803 27 31 83 325 57 44 124 576 87 51 161 811 28 32 85 334 58 44 126 584 88 51 162 819 29 32 86 342 59 44 127 592 89 51 163 827 30 33 88 350 60 44 128 600 90 51 164 835 31 33 90 359 61 45 129 608 91 52 165 842 32 34 91 368 62 45 130 616 92 52 166 849 33 34 92 377 63 45 131 624 93 52 167 856 34 35 94 386 64 45 133 632 94 52 168 863 35 35 95 395 65 46 134 640 95 52 169 870 36 36 96 403 66 46 135 648 96 53 170 876 37 36 98 411 67 46 136 656 97 53 171 882 38 37 99 419 68 46 138 664 98 53 172 888 39 37 100 427 69 47 139 672 99 53 173 894 Column 1 2 3 4 Column 1 2 3 4 100 53 174 900 Column 1 2 3 4

When one or more fixture drains are connected to a vent pipe, the vent pipe becomes a wet vent. It must then conform to all the requirements that can apply to it as a drainage pipe and a vent pipe.

Except for wet venting, fittings used to connect vent pipes to nominally horizontal soil-or-waste pipes are specified in Subsection 7.2.4.

Where multiple risers convey the water supply to dwelling units, each dwelling unit's water distribution system shall be provided with a shut-off valve located immediately where the water piping enters the suite so as to isolate the fixtures as well as the water distribution piping serving the dwelling unit's fixtures. Fixture stopcocks or shut-off valves located immediately adjacent to a fixture may not be adequate to protect the water distribution piping. Where a dwelling unit is served by a single shut-off valve on the water supply, additional shut-off valves may be required to achieve compliance with Sentences 7.6.1.3.(4) and (7). Appendix A • Volume 2 Page 161

Metallic piping may be used to extend underground non-metallic water supply piping above the floor. In these cases, the metallic pipe extension should not be used for electrical grounding purposes. Therefore, it is advisable to post a permanent sign indicating “plastic piping underground - do not use for electrical grounding purposes” in a conspicuous location.

When a check valve is required by Sentence 7.6.1.5.(1), or a backflow preventer by Articles 7.6.2.2., 7.6.2.3. or 7.6.2.6. or a pressure reducing valve by Article 7.6.3.3., protection against thermal expansion may be required.

Heritage buildings including homes, may contain sanitary drainage piping that is sized in accordance with the flush cycle of period plumbing fixtures. Operational difficulties maybe encountered when these fixtures are replaced with one having a lower flush cycle.

Flush-tank-type urinals that are not in use for an extended period of time, such as those in seasonal buildings, are permitted to be set up to flush automatically at predetermined intervals. Automatic flushing prevents the depletion of the water seal due to evaporation or backflow conditions. The trap seal restricts the infiltration of gases, which can pose health and safety concerns.

A relief valve shall not be routed through or discharge to an area where freezing temperatures may occur. If the discharge piping is longer than 2 m or more than two 90° elbows are used, the valve manufacturer’s installation instructions should be followed to ensure that the piping does not affect the relief valve’s discharge capacity.

If the discharge piping is longer than 2 m or more than two 90° elbows are used, the valve manufacturer's installation instructions should be followed to ensure that the piping does not affect the relief valves' discharge capacity.

Water hammer is a build-up of pressure in a length of horizontal or vertical pipe which occurs when a valve or faucet is closed suddenly. The longer the pipe and the greater the water velocity, the greater the pressure exerted on the pipe, which can be many times the normal static water pressure and be sufficient to burst the pipe. Ordinary kitchen and bathroom faucets can be closed quickly enough to cause water hammer even with relatively low water pressure in the pipe. Means of preventing water hammer should be installed wherever there are valves or faucets, particularly where they are at the end of long lengths of pipes. This may be done by installing either water hammer arresters which are manufactured for the purpose or air chambers installed vertically that are fabricated from pieces of piping with a closed upper end and connected to the end of the horizontal or vertical run of pipe. The air chamber should be 300 to 450 mm long if made from the same size pipe as the water pipe it serves. If the chamber is made from a pipe with larger diameter than the water pipe, its length can be reduced accordingly. Air chambers should be accessible if they are the manufactured type with top air valve and a stop-and-waste valve or are of the diaphragm type.

To accommodate the increase in pressure caused by thermal expansion within a closed water system, one of the following should be installed: (1) a suitably sized diaphragm expansion tank designed for use within a potable water system, (2) an auxiliary thermal expansion relief valve (T.E.R. valve) conforming to CAN/CSA-B125.3, “Plumbing Fittings”, set to a pressure of 550 kPa or less and designed for repeated use, or (3) other means acceptable to the authority having jurisdiction. Page 162 Appendix A • Volume 2

The Building Code regulates where a backflow preventer is required. Articles 7.6.2.1.and 7.6.2.2. require protection of potable water systems against contamination due to reversal of the normal direction of flow between a potable water system and any other system containing non-potable water or substances, where there is a direct connection between the two systems. Consequently, a backflow prevention device is required in a solar domestic hot water (SDHW) system only where there is a direct connection between the building’s potable water make-up supply and the solar heat transfer loop containing non- potable fluids. Where a non-potable heat transfer loop is charged with potable water through a charging port that is not permanently connected to a potable water system, the temporary connection to the potable water system shall include a backflow preventer or an air gap. Equipment forming part of a packaged system for solar heating of potable water must conform to CAN/CSA-F379.1, “Packaged Solar Domestic Hot Water Systems (Liquid-to-Liquid Heat Transfer)”. The installation of packaged systems for solar heating of potable water in residential occupancies must be in conformance with CSA F383, “Installation of Packaged Solar Domestic Hot Water Systems”. All other systems must be installed in accordance with good engineering practice and are expected to comply, where applicable, with the same practices required for package systems. According to Clause 7.4.3.1. of CAN/CSA-F379.1, a SDHW system that utilizes a single-wall heat exchanger is required to contain a relatively harmless heat transfer fluid (which may present minor to moderate hazard) and be properly labelled. In this case, a permanent backflow prevention device would be required on the charging line between the potable water system and the heat transfer loop only if there is a permanent direct connection between the heat transfer loop and the potable water system. Otherwise, the Building Code does not require backflow prevention devices on the domestic hot or cold potable water lines. In case of a conflict between the provisions of the Building Code and the standard, the provisions of the Building Code govern. Similarly, where a SDHW system has a double-wall heat exchanger and there is a permanent direct connection between the heat transfer loop and the potable water system, the selection of the required backflow preventer would be determined in accordance with Sentence 7.6.2.3.(1), based on the type of heat transfer fluid used and other risks. The requirement for premise isolation would be determined based on the use and the occupancy of the entire building. In most cases, the installation of a domestic solar hot water system that has a direct connection to a potable water system, alone, would not require the premise isolation referenced in Sentence 7.6.2.6.(1). “Relatively harmless” as defined in CAN/CSA-F379.1, “Packaged Solar Domestic Hot Water Systems (Liquid-to-Liquid Heat Transfer)” as a fluid having an oral LD50 of 15 000 mg/kg or greater, in accordance with Toxicity Class 6 (relatively harmless) of the Hodge and Sterner scale. The Hodge and Sterner scale is a toxicity scale recognized by the Canadian Centre for Occupational Health and Safety that provides ratings from 1 (extremely toxic) to 6 (relatively harmless) based on the LD50 approach for oral administration. LD stands for “Lethal Dose”. LD50 is the amount of a material, given all at once, which causes the death of 50% (one half) of a group of test animals. The LD50 is one way to measure the short-term poisoning potential (acute toxicity) of a material. Information is published in the material safety data sheets supplied with all heat-transfer fluid shipments, as required by Canadian law.

The following list is a guide to locations where premise isolation may be considered a moderate hazard: • shopping malls • multi-unit residential • office buildings • pleasure boat marinas • schools and colleges Appendix A • Volume 2 Page 163 The following list is a guide to locations where premise isolation may be considered a severe hazard: • hospital buildings with operating, mortuary or laboratory facilities • radioactive material processing plants • petrochemical processing facilities • premises where inspection is restricted • sewage treatment plants • commercial laundries (excluding laundromats) • plating or chemical plants • docks and dockside facilities • food and beverage processing plants • steam plants • trackside facilities for trains An assessment of the hazard must be carried out to determine the need, if any, for a backflow prevention device.

Water service pipes of 100 mm in size or larger shall be flushed and disinfected. Flushed sections shall be protected from contamination. After flushing is completed, water from the existing distribution system shall be allowed to flow at a controlled rate into the new piping. Liquid chlorine solution shall be introduced so that the chlorine is distributed throughout the section being disinfected. The chlorine shall be applied so that the chlorine concentration is 50 mg/L minimum throughout the section. Then the system shall be left charged with 50 mg/L chlorine solution for 24 hours. Test the chlorine residual piping after 24 hours. If tests indicate a chlorine residual of at least 25 mg/L, the section shall be flushed completely and recharged with water normal to the operation of the system. If the test does not meet the requirements, the chlorination procedure shall be repeated until satisfactory results are obtained. After the system has been recharged, take samples for bacteriological tests. If there is indication of contamination, the disinfection procedure shall be repeated. The system shall not be put into operation until clearance has been given by the inspector appointed by the chief building official.

Subsection 7.6.3. contains performance requirements for water systems. Two widely used references for the design of water systems are: • NIST Building Materials and Structures Report BMS 79, “Water-Distributing Systems for Buildings,” United States Department of Commerce, National Bureau of Standards, Washington, D.C., and • McGraw-Hill 2009, “International Plumbing Codes Handbook,” edited by V.T. Manas, McGraw-Hill Book Company, New York, U.S.A.

Water destined for use as potable water can originate from a variety of sources that are generally classified as surface waters or well waters, such as lakes, rivers, streams and aquifers. In some localities, there may be seasonal variations in the water supply, and surface and well waters may be blended at times. Water composition is the primary consideration in determining the cause of corrosion in potable water systems. If the water has corrosive characteristics, water treatment may be necessary to control its corrosiveness: this may be as straightforward as adjusting the pH of the water at the treatment plant, or it may involve more extensive corrosion-control treatment methods. Water purveyors normally consult treatment specialists to develop methods suitable for specific conditions. The treatment of water from private wells may also require expert consultation. Page 164 Appendix A • Volume 2 The past performance of plumbing materials and products in different localities often provides insight into what can be expected with new installations. In areas where water-related corrosion is known to occur, adjustment of water chemistry may be sufficient, or it may be necessary to select alternative piping and fitting materials or more robust products. It is important to note that not all corrosion can be attributed to water conditions: the improper design and installation of potable water systems may result in erosion corrosion, galvanic corrosion, fatigue cracking, and so forth.

The design procedures contained in the following documents are considered good engineering practice in the field of potable water systems: (a) 2011 ASHRAE Handbook of HVAC Applications, Chapter 50, “Service Water Heating”, (b) 2009 ASHRAE Handbook of Fundamentals, Chapter 22, “Pipe Sizing”, (c) 2005 ASPE Data Book - Volume 2, Chapter, 5, “Cold Water Systems”, and (d) 2005 ASPE Data Book - Volume 2, Chapter, 6, “Domestic Water Heating Systems Fundamentals”. Alternative procedures shown below are also acceptable. Table A-7.6.3.1. Pipe Size Based on the Number of Fixtures Units Served(1) Water Maximum Allowable Length, m Water Distribution Service, System, 12 18 24 30 46 61 76 91 122 152 183 213 244 274 305 inches inches Pressure Range Number of Fixture Units Served 200 to 310 kPa (30 to 45 psi) ¾” ½” 6 5 4 3 2 1 1 1 0 0 0 0 0 0 0 ¾” ¾” 18 16 14 12 9 6 5 5 4 4 3 2 2 2 1 ¾” 1" 29 25 23 21 17 15 13 12 10 9 7 6 6 6 6 1" 1" 36 31 27 25 20 17 15 13 12 10 8 6 6 6 6 1½" 1¼” 90 68 57 48 38 32 28 25 21 18 15 12 12 11 11 1½" 1½" 151 124 105 91 70 57 49 45 36 31 26 23 21 20 20 2" 1½" 151 151 132 110 80 64 53 46 38 32 27 23 21 20 20 2" 2" 359 329 292 265 217 185 164 147 124 96 70 61 57 54 51 2½" 2½” 445 418 390 370 330 300 280 265 240 220 198 175 158 143 133 311 to 413 kPa (46 to 60 psi) ¾” ½” 8 7 6 5 4 3 2 2 1 1 1 0 0 0 0 ¾” ¾” 21 21 19 17 14 11 9 8 6 5 4 4 3 3 3 1" 1" 42 42 41 36 30 25 23 20 18 15 12 10 9 8 8 1½" 1¼” 83 83 83 83 66 52 44 39 33 29 24 20 19 17 16 1½" 1½" 151 151 151 151 128 105 90 78 62 52 42 38 35 32 30 2" 1½" 151 151 151 151 150 117 98 84 67 55 42 38 35 32 30 2" 2" 359 359 359 359 359 318 280 250 205 165 142 123 110 102 94 2½" 2½” 611 611 610 580 535 500 470 440 400 365 335 315 285 267 250 Appendix A • Volume 2 Page 165 Water Maximum Allowable Length, m Water Distribution Service, System, 12 18 24 30 46 61 76 91 122 152 183 213 244 274 305 inches inches Pressure Range Number of Fixture Units Served Over 413 kPa (60 psi) ¾” ½” 8 8 7 6 5 4 3 3 2 1 1 1 1 1 0 ¾” ¾” 21 21 21 21 17 13 11 10 8 7 6 6 5 4 4 1" 1" 42 42 42 42 38 32 29 26 22 18 14 13 12 12 11 1½" 1¼” 83 83 83 83 83 74 62 54 43 34 26 25 23 22 21 1½" 1½" 151 151 151 151 151 151 130 113 88 73 51 51 46 43 40 2" 1½" 151 151 151 151 151 151 142 122 98 82 64 51 46 43 40 2" 2" 359 359 359 359 359 359 359 340 288 245 204 172 153 141 129 2½” 2½” 611 611 611 611 611 611 610 570 510 460 430 404 380 356 329 Column 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Notes to Table A-7.6.3.1.: (1) Where total fixture unit values exceed those given in this Table, the system must be designed according to a detailed engineering design method.

Distribution piping and water mains serving flush valves may be sized using the values assigned in Tables 7.6.3.2.-B and 7.6.3.2.-C, beginning with the most remote flush valve on each section of distribution piping served by the water main.

Where separate water service piping connects into private water supply piping, the private water supply piping will be governed by Article 7.1.5.5.

Examples of water shut-off devices include occupant sensors and self-closing valves.

When replacing a shower head, the appropriate shower valve with a suitable compensating feature matching the flow rate should be chosen to decrease the possibility that users will suffer thermal shock. The water flow rate of automatic compensating mixing valves can be found in ASSE 1016 / ASME 112.1016 / CSA B125.16, “Performance Requirements for Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations”.

There is a growing interest in Canada in using available non-potable water supplies in the place of potable ones for selected purposes such as flushing water closets and irrigating lawns and gardens. Article 7.7.1.1. applies to non-potable water systems, regardless of the origin of the water. The non-potable water must meet applicable water quality standards as determined by an authority having jurisdiction.

Examples of good engineering practice in the design, fabrication and installation of non-potable water systems can be found in • the ASHRAE Handbooks, • the ASPE Handbooks, and • CAN/CSA-B128.1, “Design and Installation of Non-Potable Water Systems.” Page 166 Appendix A • Volume 2

While it is possible to harvest rainwater from surfaces other than above-ground roofs, such as patios, lawns, gardens, driveways, roadways, parking garages and parking lots, these surfaces are not suitable catchments for rainwater harvesting systems because of water quality concerns. Water collected from such surfaces may be contaminated with fertilizer, herbicides, fecal matter, garbage, oil or chemicals. The outdoor environment in the local area of the building site, including its immediate surroundings, should be investigated to identify contaminants that could adversely affect the quality of the non-potable water delivered by the rainwater harvesting system. Contaminants of concern include industrial and urban traffic emissions, and pesticides and other agricultural chemicals. Other factors that can influence the levels of contaminants in the delivered non-potable water include the building's geometry, and prevailing winds and seasonal activity in the local area. Design features should be incorporated in the rainwater harvesting system to mitigate the risks associated with any identified contaminants of concern.

Harvested rainwater used in any permitted application must be treated appropriately for its intended end use.

The prohibition of pedestrian traffic on roof surfaces stated in Sentence 7.7.2.3.(1) is not intended to include access to roof surfaces by service personnel, such as window washers or HVAC mechanics.

Water is considered to be the “universal solvent.” Accordingly, roofing components and conveyance systems that supply rainwater to a rainwater harvesting system should be constructed of materials that resist dissolution in water. NSF Pro 151-8- 1, “Health Effects from Rainwater Catchment System Components,” although directed at potable water systems, is a useful source of information on roofing materials to consider.

Examples of good engineering practice in the design, fabrication and installation of rainwater harvesting systems can be found in • the ASHRAE Handbooks, • the ASPE Handbooks, • ARCSA/ASPE/ANSI 63, “Rainwater Catchment Systems,” and • CSA B805/ICC 805, “Rainwater harvesting systems.”