RELATES TO: 318.015, 318.130, 318.150,
NECESSITY, FUNCTION, AND CONFORMITY: KRS 318.130 requires the department to promulgate administrative regulations establishing the Kentucky State Plumbing Code regulating plumbing, including the methods and materials that may be used in Kentucky for soil, waste, and vent systems. This administrative regulation establishes the minimum requirements for and manufacturer's specification number of the material accepted in the installation and design of soil, waste, vent systems, traps, and clean-outs in each type of plumbing system.
Section 1. Materials.(1) Main or branch soil, waste, and vent pipes and fittings within or underneath a building shall be:(a) Hub and spigot extra heavy or service weight cast iron;(b) No-hub service weight cast iron;(d) Galvanized wrought iron;(g) Types K, L, M, and DWV copper;(h) Standard high-frequency welded tubing produced and labeled with the latest ASTM specifications;(i) Types R-K, R-L, R-DWV brass tubing;(j) DWV brass tubing produced and labeled as ASTM B587;(k) Seamless stainless steel tubing;(I) Grade G or H produced and labeled as ASTM A312;(m) PVC schedule 40 or 80 produced and labeled as ASTM D2665, D1784, and F891;(n) Coextruded composite PVC pipe produced and labeled ASTM F1488;(o) ABS schedule 40 or 80 produced and labeled as ASTM D2661, F1488, or F628;(p) CPVC schedule 40 or 80; or(q) Silicon iron or borosilicate.(2) A main or branch soil waste and vent pipe and fittings underground shall either be: (a) Hub and spigot extra heavy or service weight cast iron;(b) No-hub service weight cast iron;(c) Type K or L copper pipe;(d) Type R-K, R-L brass tubing;(f) Silicon iron or borosilicate pipe and fittings or plastics DWV established in this section.(3) Underground waste pipe installed beneath a concrete slab shall:(a) Not be less than two (2) inches in diameter; and(b) Extend no less than twelve (12) inches above the concrete slab.(4) A trap for a bathtub, lavatory, sink, or other similar fixture shall be made of:(b) Tubular ABS or PVC produced and labeled as ASTM F409;(h) Grade G or H produced and labeled as ASTM A312; or(i) CPVC schedule 40 or 80.(5) A tubular or schedule 40 PVC, or a tubular or schedule 40 ABS p-trap shall be either the union-joint or solvent welded type.(6) A tubular brass trap shall be seventeen (17) gauge.(7) A tubular brass trap, tubular PVC trap, or tubular ABS trap shall not be installed below the finished floor serving a fixture.(8) The threads in a cast brass or cast iron trap shall be tapped out of solid metal.(9) A lead trap shall be extra heavy.Section 2. Trap Requirements.(1) Trap placement. A fixture shall be separately trapped by a water-seal trap placed as near as possible to the fixture, but not to exceed ten (10) inches from the bottom of the fixture to the dip of the seal.(2) Water seal. A fixture trap shall have a water seal not less than two (2) inches nor more than four (4) inches.(3) Waste discharge. Waste from a bathtub or other fixture shall not discharge into a water closet bend.(4) Double trap prohibition. A fixture shall not be double trapped.(5) A trap shall have a full-bore, smooth interior waterway.(6) Self-cleaning. A trap shall be self-cleaning.(7) Trap clean-outs. A trap clean-out shall be optional.(8) Trap levels and protection. A trap shall be:(a) Set true with respect to its water seal; and(b) Protected from frost and evaporation(9) Trap primers. Trap primers shall be required on:(a) Floor drains only in mechanical rooms or boiler rooms; and(b) All open receptacles that receive the discharge from a temperature and pressure relief device discharge only.(10) Protected Traps and Vents.(a) A fixture trap shall be protected against siphonage and backpressure.(b) Air circulation shall be assured by means of an individual vent.(c) A crown vent shall not be permitted.(d) An open drain, such as a hub drain or open receptacle, shall not be installed within a plenum space.(11) Distance of Trap from Vent. (a)1. The distance between the vent and the fixture trap shall be measured along the center line of the waste or soil pipe from the vertical inlet of the trap to the vent opening.2. The fixture trap vent, except for a water closet or a similar fixture, shall not be below the dip of the trap, and each ninety (90) degree turn in the waste line of the main waste, soil, or vent pipe shall be washed.3. A fixture trap shall have a vent located with a developed length not greater than that in the following table: Size of Fixture Drain (In Inches) | Distance Trap to Vent |
1 1/4 | 2 ft. 6 in. |
1 1/2 | 3 ft. 6 in. |
2 | 5 ft. |
3 | 6 ft. |
4 | 10 ft. |
(b) A fixture branch on a water closet shall not be more than four (4) feet six (6) inches.(12) Grease traps. (a) If a grease trap is installed, it shall be:1. Placed as near to the fixture it serves as practical; and2. Approved by the department.(b) A grease trap used inside a building shall:1. Have a sealed cover; and(c) A grease trap for a restaurant, food service establishment, or other business establishment shall be installed:1. As required by municipal ordinance; or2. As required by 902 KAR 10:085, if a food establishment uses a private sewage system.(13) Sand Traps. A sand trap shall be: (a) Readily accessible; and(b) Serve the purpose intended.(14) Slip joints. (a) Slip joints shall be permitted on the inlet side of the trap.(b) A single one and one-half (1 1/2) inch slip joint connection with an elastomeric gasket shall be permitted on the outlet side of a one and one-half (1 1/2) inch trap.Section 3. Pipe Clean-out Requirements. (1) The bodies of clean-out ferrules shall be made in a standard pipe size, conforming in thickness to that of the pipe and fittings and shall not extend less than one-quarter (1/4) inch above the hubs in which they are placed.(2) The clean-out cap or plug shall be yellow-brass, PVC, or ABS no less than one-eighth (1/8) inch thick and shall have a raised nut or recessed pocket for removal.(3) In a building served by a stack over forty-five (45) feet in height, a clean-out shall be provided at the base of each vertical waste or soil stack.(4) There shall be at least one (1) clean-out in the building drain with a full-size branch inside the wall or outside the building at a point not to exceed two (2) feet from the foundation wall. This clean-out shall be a two (2) directional fitting or a combination of sanitary tees or tee wyes to allow cleaning in both directions.(5) If located outside the building, the clean-out shall be extended to the finished grade for accessibility.(6) A clean-out shall be of the same nominal size as the pipe it serves up to four (4) inches and shall not be less than four (4) inches for larger pipe.(7) A clean-out installed on a four (4) inch sewer shall be a two (2) directional fitting or a combination of sanitary tees or tee wyes to allow cleaning in both directions.(8) The distance between clean-outs in all sewers shall not exceed 150 feet.(9) An underground clean-out in a building shall be:(a) Flush with the floor or wall; or(b) Accessible by a manhole.(10) A floor or wall connection of a fixture shall be regarded as a clean-out, except where the house drain enters a building.Section 4. Grades and Supports of Horizontal Piping.(1)(a) Horizontal piping shall run in practical alignment and at a uniform grade of not less than one-eighth (1/8) inch per foot and shall be supported or anchored in accordance with the manufacturer's recommendations.(b) The supports or anchors shall not be placed at intervals that exceed ten (10) feet in length.(2) A stack shall be supported at its base, and each pipe shall be rigidly secured.(3) No-hub pipe and fittings shall be supported at each joint of pipe and fittings.(4) PVC and ABS schedule forty (40) horizontal piping shall be supported at:(a) Intervals not to exceed four (4) feet;(b) The base of each vertical stack; and(c) Each trap branch as close to the trap as possible.(5) PE pipe and fittings shall be continuously supported with a V channel.(6) A stack shall be rigidly supported at its base and at the floor level.Section 5. Change in Direction.(1) Except as provided in subsections (2), (3), or (4) of this section, a change in direction shall be made by the appropriate use of a forty-five (45) degree wye, half-wye, quarter (1/4), sixth (1/6), eighth (1/8) or sixteenth (1/16) bend.(2) A single sanitary tee may be used in a vertical stack.(3) A sanitary tee may be turned on its back or side. If turned on its back or side, a sanitary tee shall not be placed at an angle of more than forty-five (45) degrees.(4) A double sanitary tee may be used on a vertical soil, waste, and vent line.Section 6. Direct Flow Fittings and Continuous-waste. A kitchen sink unit or a fixture with more than one (1) unit may be connected with a continuous-waste, if a directional flow fitting is used. Continuous-waste shall be either seventeen (17) gauge tubular brass, schedule 40 ABS, schedule 40 PVC, tubular ABS, or tubular PVC.Section 7. Prohibited Fittings. (1) The following shall be prohibited: (a) A double hub bend and double hub tee or inverted hub on a sewer, soil, or waste line;(b) The drilling and tapping of a house sewer or house drain, soil, waste, or vent pipe;(c) The use of a saddle hub; and(d) Pipe installed with a hub or restriction that reduces the area or capacity of the pipe.(2) Prohibited traps. A trap shall not be used if the trap depends upon: (a) The action of a movable part; or(b) Concealed interior partition for its seal.Section 8. Dead Ends. A dead end shall not be used in the installation of a drainage system.Section 9. Protection of Material. (1) A pipe passing under or through a wall shall be protected from breakage.(2) A pipe passing through or under cinder, concrete, or other corrosive material shall be protected against external corrosion.(3)(a) Soil, waste, or vent pipe shall not be installed or permitted outside a building unless adequate provision shall be made to protect it from frost.(b) The vent shall be increased to full size, the size of the increaser required as if it were passing through the roof.Section 10. Size of Soil and Waste Pipe per Fixture Unit on One (1) Stack.(1) The following table, based on the rate of discharge from a lavatory as a unit, shall be employed to determine fixture equivalents: Pipe Size (In Inches) | Maximum Developed Length | Fixture Units |
1 1/4 | 25 ft. | 1 |
1 1/2 | 60 ft. | 2 |
2 | 80 ft. | 6 |
2 1/2 | 100 ft. | 12 |
3 | 225 ft. | 36 |
4 | unlimited | 172 |
5 | unlimited | 342 |
6 | unlimited | 576 |
8 | unlimited | 1600 |
10 | unlimited | 2900 |
12 | unlimited | 4600 |
(2) A water closet shall be on a minimum of a three (3) inch soil and waste pipe with a maximum of three (3) water closets or soil discharging fixtures per three (3) inch soil and waste pipe. Four (4) water closets with a maximum flushing rate of one and six-tenths (1.6) gallons per flush per water closet shall be allowed to discharge into a three (3) inch soil and waste pipe.Section 11. Soil and Vent Stacks. (1) A building in which a plumbing fixture is installed shall have a soil or waste and vent stack, or stacks, extending full size through the roof.(2) A soil or waste and vent stack shall be as direct as possible and free from sharp bends or turns.(3) The required size of the soil or waste and vent stack shall be determined from the total fixture units connected to the stack in accordance with Section 10 of this administrative regulation except that more than: (a) Three (3) water closets with a flush rate of three and five-tenths (3.5) gallons per flush shall not discharge into a three (3) inch stack; and(b) Four (4) water closets with a flush rate of one and six-tenths (1.6) gallons per flush or less shall not discharge into a three (3) inch stack.Section 12. Future Openings. An existing opening or an opening installed in a plumbing system for future use shall be complete with its soil, waste, and vent piping and shall comply with this administrative regulation.Section 13. House Drain. (1) The size of the house drain shall be determined by the total number of fixture units connecting to the house drain. The total area of vents through the roof shall be equal to that of the house drain with a minimum of one (1) three (3) inch stack.(2) If a three (3) inch house drain enters a building, it shall be attached to a three (3) inch stack. One (1) floor drain may be added to the house drain if it conforms with the requirements of Section 23 of this administrative regulation, without counting toward the fixture units of the system.Section 14. Soil and Waste Stacks, Fixture Connections. (1) A soil and waste stack or branch shall have correctly faced inlets for fixture connections.(2) Each fixture shall be independently connected to the soil or waste system.(3) A fixture connection to a water closet, floor-outlet pedestal sink, pedestal urinal, or other similar plumbing fixture shall be:(4) A three (3) inch closet bend shall have a four (4) inch by three (3) inch flange.Section 15. Changing Soil and Vent Pipes in an Existing Building. Soil, waste, and vent piping shall be replaced with appropriate size and materials for new work as prescribed by this administrative regulation, if:(1) The fixtures are to be changed or replaced; and(2)(a) The soil, waste, and vent piping in an existing building is not extended undiminished through the roof; or(b) There is sheet metal soil or waste piping.Section 16. Prohibited Connections.(1) A fixture connection shall not be made to a lead bend or a branch of a water closet or a similar fixture.(2) A vent pipe above the highest installed fixture on a branch or main shall not be used as a soil or waste pipe.Section 17. Roof Extensions.(1) A roof extension of soil and waste stacks shall run full size at least one (1) foot above the roof.(2) If the roof is used for purposes other than weather protection, the extension shall not be less than five (5) feet above the roof.(3)(a) A stack of less than three (3) inches in diameter shall be increased to a minimum of three (3) inches in diameter before passing through a roof.(b) If a change in diameter is made, the fitting shall be placed at least one (1) foot below the roof.Section 18. Terminals. (1) Terminals on buildings. The terminus of a stack or vent shall extend at least two (2) feet above the top edge of a door, window, scuttle, or air shaft, if the roof terminus is: (a) Within ten (10) feet of the top, bottom, face, or side edge of a door, window, scuttle, or air shaft; and(b) Not screened from the opening by a projecting roof or building wall.(2) Terminals Adjoining High Buildings. (a) Except when soil, waste, or vent piping is protected from freezing, a pipe extension of a new or existing building shall be installed inside the building and shall not run or be placed on an outside wall.(b) If the new building is built higher than the existing building, the owner of the new building shall not locate a window within ten (10) feet of an existing vent stack on the lower building.Section 19. Main Vents to Connect at Base. (1) All main vents or vent stacks shall: (a) Connect full size at the base of the main soil or waste pipe at or below the lowest fixture branch; and(b) Extend undiminished in size through the roof or be reconnected with the main soil or vent stack at least six (6) inches above the rim of the highest fixture.(2)(a) Except as established in paragraph (b) of this subsection, if it becomes necessary to increase the size of a vertical vent stack, the entire stack shall be increased from its base.(b) If the height of a stack which does not serve as the main vent is less than forty-five (45) feet, it shall not be required to be increased from its base.Section 20. Vents; Required Sizes.(1) The required size of a vent or vent stack shall be determined by the total number of fixture units it serves and the developed length of the vent, interpolating, if necessary, between permissible length of vent given in the following table: MAXIMUM PERMISSIBLE LENGTHS OF VENTS |
Pipe Size (In Inches) | Maximum Length (In Feet) | Fixture Units |
1 1/4 | 30 | 2 |
1 1/2 | 150 | 10 |
2 | 200 | 24 |
2 1/2 | 250 | 36 |
3 | 300 | 72 |
4 | 400 | 240 |
5 | 600 | 420 |
6 | 800 | 720 |
(2) Except for a residential installation, if a fixture opening is installed more than twenty-five (25) feet of developed length from the point where it is connected to the main soil or waste system, or, if more than ten (10) feet of vertical piping is used, the vent shall be continued full size through the roof or returned full size to the main vent.Section 21. Branch and Individual Vents. A branch or individual vent shall not be less than one and one-fourth (1 1/4) inches in diameter and shall not exceed the maximum length permitted for a main vent.Section 22. Vent Pipes Grades and Connections.(1) A vent or branch vent pipe shall be free from drops or sags and be so graded and connected as to drip back to the soil or waste pipe by gravity.(2) If a vent pipe connects to a horizontal soil or waste pipe, the vent branch shall be taken off above the center line of the pipe, and the vent pipe shall rise vertically at an angle of forty-five (45) degrees to the vertical, to a point six (6) inches above the fixture it is venting before offsetting horizontally or connecting to the branch, main, waste, soil or vent.Section 23. Vents Not Required; Backwater Traps, Subsoil Catch Basin, and Basement Floor Drains.(1) A vent shall not be required on a backwater trap, subsoil catch basin trap, or a basement floor drain if the basement floor drain branches into the house drain so that measuring along the flow line from the center of the stack, the floor drain shall not be closer than five (5) feet of the stack, nor farther than twenty (20) feet.(2) A basement floor drain shall not require an individual vent if it branches into the house drain so that measuring along the flow line from the center of the house drain the basement floor drain shall not be farther than ten (10) feet from the house drain.Section 24. Permissible Common Vent Conditions.(1) A common vent or a common soil and waste pipe may be used if: (a) Two (2) water closets, two (2) lavatories, or two (2) fixtures of identical purpose are located on opposite sides of a wall or partition; or(b) Directly adjacent to each other within the distance established in Section 2(11) of this administrative regulation measured along the center line of the flow of water.(2) Double sanitary tee or sanitary cross shall not be used if a common vent or a common soil and waste pipe are connected through a double fixture fitting for a water closet of less than 1.6 gallons per flush.(3) A common vent or common soil and waste pipe shall be vented in accordance with this administrative regulation.Section 25. Floor Drain Individual Vent Not Required. (1) A manufacturer's floor drain shall not require an individual vent if placed on a waste line for a floor drain within the distance of ten (10) feet from the main waste line, or stack, if the base of the stack is washed and the stack or stacks are undiminished through the roof, or connected to a main vent stack.(2) An open receptacle may be connected to a floor drain line without being vented if the waste line discharges into a four (4) inch master trap before entering the sanitary sewer system.Section 26. Floor Drain at a sewage and water treatment plant. A floor drain or service sink installed on the operational floor level of a sewage and water treatment plant facility that discharges into an open sump and is not connected directly to the sanitary sewage system shall not be required to be trapped or vented.Section 27. House Drain Material. A house drain shall be: (1) Extra heavy cast iron;(2) Service weight cast iron;(4) Type (K) or (L) copper;(6) ABS or PVC plastic; orSection 28. Indirect Waste Connections. (1) Waste pipe from a refrigerator drain or other receptacle where food is stored or waste water from a water cooled compressor shall connect indirectly with the house drain, soil, or waste pipe.(2) The drain shall be vented to the outside air.(3) The waste pipe shall discharge into an open sink or another approved open receptacle that is properly supplied with water in accordance with this administrative regulation.(4) The connection shall not be located in an inaccessible or unventilated area.Section 29. Bar and Soda Fountain Wastes.(1)(a) A bar and soda fountain waste, sink, or receptacle shall have a one and one-half (1 1/2) inch P trap and branches.(b) The main shall not be less than two (2) inches.(c) The fresh air pipe shall not be less than one and one-half (1 1/2) inches.(d) The main waste line shall discharge into a properly vented and trapped open receptacle inside or outside a building.(2) A floor receptor or floor sink may be installed flush with the finished floor if it has a full grate with an attached funnel to receive indirect waste.(3) A floor receptor or floor sink installed specifically for the indirect wastes from a tilting braising pan, tilting kettle, or other similar equipment may be installed level with or slightly recessed in the floor if the receptor is equipped with a proper strainer and receives no other indirect waste.Section 30. Open Receptacles. Soil or waste piping receiving the discharge from an open receptacle shall be at least six (6) inches above the surface of the ground if it discharges into a septic system.Section 31. Refrigerator and Condensate Wastes.(1) A refrigerator or condensate discharge waste pipe shall not be less than: (a) One and one-half (1 1/2) inches for one (1) to three (3) openings; and(b) Two (2) inches for four (4) to eight (8) openings.(2) Each opening shall be trapped.(3) The waste piping shall be equipped with sufficient cleanouts to allow for thorough cleaning.Section 32. Overflow Pipes. (1) Waste from a water supply tank or exhaust from a water lift shall not be directly connected to a house drain, soil, or waste pipe.(2) The waste pipe shall discharge upon a roof or into a trapped open receptacle.Section 33. Acid and Chemical Wastes.(1) A corrosive liquid shall not be permitted to discharge into the soil, waste, or sewer system unless otherwise permitted by this administrative regulation.(2) The waste shall be thoroughly diluted or neutralized by passing through a properly constructed and acceptable dilution or neutralizing pit before entering the house sewer.Section 34. Laboratory Waste Piping. (1) Laboratory waste piping shall be sized in accordance with this administrative regulation and each fixture shall be individually trapped.(2) A continuous waste and vent pipe system may be used if the waste discharges into a vented dilution pit outside the building with a vent equal to the size of the drain. The vent may be eliminated if the pit has a ventilated cover.(3) If a dilution pit is not required and is not used, the fixtures shall be individually vented.(4) If construction conditions permit, the base of the stack of the continuous waste and vent system shall be washed by the last fixture opening, and continue full size independently through the roof.(5) A fixture branch exceeding more than the distance established in the table in Section 2(11) of this administrative regulation from the main shall be revented, and the distance shall be measured from the center of the main to the center of the vertical riser.(6)(a) A fixture connection shall rise vertically to a height so that the trap shall not be lower than twelve (12) inches from the bottom of the sink.(b) Two (2) or more sinks may be connected into a common waste before entering the riser of the continuous waste and vent system, if the fixtures are not more than five (5) feet from the center of one (1) fixture to the center of the other.Section 35. Acid Waste Piping. (1) Underground piping for acid wastes shall be:(a) Extra heavy salt glazed vitrified pipe;(d) PE pipe and fittings produced and labeled as ASTM D204;(e) PP pipe produced and labeled as ASTM D4101;(f) PP pipe and fittings produced and labeled as ASTM F1412;(g) CPVC Chemical Waste Drainage Systems meeting ASTM F2618; or(h) Other materials approved in 815 KAR 20:020, Section 4.(2) Piping for acid wastes and vents above ground shall be:(d) PE pipe produced and labeled as ASTM D120462T;(e) PP pipe produced and labeled as ASTM D410185;(f) Filament-wound reinforced thermosetting resin pipe produced and labeled as ASTM D2996 (green or poly thread); or(g)CPVC Chemical Waste Drainage Systems meeting ASTM F2618.Section 36. Special Vents. A flat vent may be allowed if the design of the building prohibits the type of venting required by this administrative regulation.Section 37. Basement Floor Drains.(1) A basement floor drain shall be:(a) Connected to the house sewer;(b) Properly trapped and vented;(c) Readily accessible for cleaning; and(d) Of sufficient size to serve the purpose intended.(2) If a drain is subject to back flow or back pressure, the drain shall be equipped with a back water valve that complies with Section 38 of this administrative regulation.(3)(a) A basement floor drain shall not be connected to the house sewer and shall be exempt from this section if, prior to the installation, the local health department or sanitary sewage system board, plant, district, or treatment plant owner notifies the division, in writing, that connection is detrimental to the functioning of the sanitary sewer system or subsurface system.(b) If the drain is not to be connected to the house sewer, the installation shall also be exempt from the waste, trap, and venting provisions of this code.Section 38. Back Water Valves. A back water valve shall be:(1) Made of noncorrosive material; and(2) Constructed to ensure a positive mechanical seal, except if discharging waste.Section 39. Residential Laundry Room Floor Drains. A two (2) inch floor drain with an individual waste and vent may be installed in a residential laundry room.1 Ky.R. 481; eff. 3-12-1975; 2 Ky.R. 148; eff. 8-13-1975; 451; 3 Ky.R. 772; 4 Ky.R. 100; eff. 8-3-1977; 186; 539; eff. 6-7-1978; Recodified from 401 KAR 1:060, 7-5-1978; Am. 6 Ky.R. 134; eff. 1-2-1980; 7 Ky.R. 509; eff. 1-7-1981; 846; eff. 6-3-1981; 9 Ky.R. 834; eff. 2-2-1983; 1238; eff. 6-1-1983; 14 Ky.R. 1129; eff. 1-4-1988; 16 Ky.R. 72; eff. 8-22-1989; 1272; 1590; eff. 8-22-1989; 18 Ky.R. 2722; eff. 4-3-1992; 3537; 19 Ky.R. 411; eff. 8-1-1992; 1192; 1556; eff. 1-4-1993; 22 Ky.R. 1386; eff. 3-7-1996; 23 Ky.R. 2691; 2990; eff. 2-10-1997; 3978; eff. 6-25-1997; 27 Ky.R. 1905; 2796; eff. 3-22-2001; 30 Ky.R. 2393; 31 Ky.R. 88, eff. 8-6-2004; 32 Ky.R. 2367; 33 Ky.R. 408; eff. 9-120-2006; 34 Ky.R. 1239; 1750; eff. 2-1-2008; 35 Ky.R. 2594; 36 Ky.R. 88; eff. 7-29-2009; 35 Ky.R. 2594; 36 Ky.R. 88; 1352; eff. 3-5-2010; 41 Ky.R. 175; eff. 9-24-2014; 43 Ky.R. 461; eff. 11-16-2016; 46 Ky.R. 1668, 2431; eff. 6-2-2020.STATUTORY AUTHORITY: KRS 198B.040(10), 318.130