Slope for drainage as per is code. A branch shall be not less than 1 / 2 -inch (12.

" Except for individual Jan 19, 2015 · (For more information: 12 Tables of Code) Name of Standards Organization: Indian Roads Congress (IRC) Designator of Legally Binding Document: IRC SP 042 Title of Legally Binding Document: Guidelines on Road Drainage (First Revision) LEGALLY BINDING DOCUMENT Step Out From the Old to the New--Jawaharlal Nehru Invent a new India using knowledge. MINIMUM SLOPE %. A 25-foot patio would need a drop of 6. Fixtures not listed in Table 709. The published roof drain flow rate, based on the head of water above the roof drain, shall be used to size the storm drainage system in accordance with Section 1106. So show me the May 12, 2023 · Pipe slope, or the gradient of your sanitary drainage pipe, is a crucial factor in the effectiveness of waste disposal. 4 mm, 1 . The replacement piping shall be of the same nominal size as the existing piping. The minimum slope you should have on your drain pipe however should be 1%. Joints for hub and spigot pipe shall be firmly packed with oakum or hemp. 4 and Figure R403. 7. Valves shall be made of materials that are approved in the Florida Building Code, Plumbing. 2 and Chapter 14 "Firestop Protection. Jul 8, 2024 · Slope Recommendation: A minimum slope of ¼ inch per foot is recommended for driveways. 8 Drainage for Structures 53 6. Construct the foundation walls high enough to maintain a slope of at least 6 inches down within the first 10 feet away from the structure after construction is completed and the area around the home is back filled and tamped, then topped with concrete or pavers or top soil and landscaping Many will point to where the ICC energy efficiency code states: N1103. CALIFORNIA PLUMBING CODE - MATRIX ADOPTION TABLE. Except as provided in Section R403. 1 Slope of horizontal drainage piping. Where the diameter of the drain is increased, the crown of the pipe shall be fixed at the same level and necessary slope given in the invert of the manhole chamber. 11. If a garage is used for parking vehicles, its floor is required to be sloped per the International Residential Code (IRC). 1 - SLOPE OF HORIZONTAL DRAINAGE PIPE 709. Practical Considerations: Chapter 7 Sanitary Drainage. 701. Solution 2: Camber. CHAPTER 7 - SANITARY DRAINAGE. 2. For SI: 1 inch = 25. 7 mm) nominal pipe size for one outlet and shall be sized in accordance with the number of vacuum outlets. ABS and PVC DWV piping installations shall be installed in accordance with applicable standards referenced in Table 701. 1110. Don’t backfill until foundation walls are anchored to the floor framing [404. The finished floor shall slope uniformly toward the drain not less than 1 / 4 unit vertical in 12 units horizontal (2-percent slope) nor more than 1 / 2 unit vertical per 12 units horizontal (4-percent slope) and floor drains shall be flanged to provide a water-tight joint in the floor. It can be used for building the proper pitch into a plumbing drainage system in a bathroom, kitchen, or even outdoors for rain water drainage. 1h ) where a drainage system is required; and Oct 20, 2023 · In conclusion, there are specific building codes and regulations that dictate the minimum slope requirement for bathroom floors. 5 Catch Water Drains 51 6. Code of practice for under drainage of lined canals (second revision) Guidelines for lining of canals III expansive soils (second revision)-ISNo. 2 Secondary (emergency overflow) drains or scuppers. CBC provisions provide minimum standards to safeguard life or limb, health, property, and public welfare by regulating and controlling the design, construction, quality of 704. Dec 1, 2023 · The ideal slope for drain and sewer pipes is generally between 1/4 inch and 3/8 inch per linear foot (2% to 3% slope). 1112. This gentle incline allows for efficient water shedding and prevents ponding. Gutters and downspouts shall be installed so that water does not pool at any point. But that excerpt really isn't talking about condensate drains when read in context. But this minimal slope does not provide sufficient drainage. SLOPE. **The horizontal combination waste and vent pipe shall have a maximum slope of one-half unit vertical in 12 units horizontal (4-percent slope). 5 inches. Where scuppers are used for primary roof drainage or for secondary (emergency overflow) roof drainage or both, the quantity, size, location and inlet elevation of the scuppers shall be chosen to prevent the depth of ponding water on the roof from exceeding the maximum water depth that the roof was designed for as determined by Section 1611. 716. 60 degrees), applicable only to coal tar pitch roof systems. STANDARD. 9 kPa) or less. A floor drain itself does not add hydraulic load. 1 shall have a drainage fixture unit load based on the outlet size of the fixture in accordance with Table 709. 1106. Aug 1, 2018 · In cases of roof system replacement and re-cover of existing low-slope roof systems, IBC 2018 and IRC 2018 waive the codes' 1/4:12 minimum slope requirement and apply a performance-based, positive roof drainage minimum requirement. Design and installation of roof drainage systems shall comply with this section, Section 1611 of this code and Chapter 11 of the International Plumbing Code. 9. 2 mm) below the rim of the hub and shall be caulked tight. 7 Internal Drainage of Pavement Structure 52 6. Consistency is Key. A 1% slope on your drain line means that for every 1 foot that the pipe travels horizontally it drops vertically by 1/8 inch. P2912. 3-percent slope). Gutters and downspouts shall have a slope of not less than 1 / 8 inch per foot (10. In exceptional cases and where unavoidable, the crown of the branch sewer may be fixed at a lower level but in such cases the peak flow level of the two sewers should be kept the same. 25 inches, and so on. If you have a 10-foot patio, then your drop will be 2. In addition to the provision made in IS : 456 - 1978*, all construction joints in walls and floors shall be filled with approved sealant All of your drain pipe (with one exception) must slope slightly downhill. For a continuous or semicontinuous flow into a drainage system, such as from a pump or similar device, 1. A Fixture Unit is not a flow rate unit but a Dec 24, 2023 · The general rule of thumb for drain pipe slope is to have a 1/4-inch slope per foot of pipe. For a fixture not listed, use the highest d. Horizontal drainage piping shall be installed in uniform alignment at uniform slopes. If your deck surface is solid or if your deck boards run R4501. 9 Existing Drains, Canals and Minor Waterways 54 Jan 27, 2010 · Below-grade basement walls need damp-proofing [406. Size of Drain or Sewer, inches Maximum Hydraulic Load, L: Slope: 1 in 400: 1 in 200: 1 in 133: 1 in 100: 1 in 68: 1 in 50: 1 in 25: 3 — — — — — 705. For pipes 3 inches or larger in diameter, a 1/8 inch per foot Proper drainage is important to protect structures from moisture damage and erosion. (3) Where it is not possible to comply with Sentence (1), a lesser slope may be used if it will The slope of a horizontal drainage pipe shall be not less than that indicated in Table 704. Plain-ended gutters. PREVENTION OF SUBSOIL WATER 5. Storm-Water Conductors Roof drain capacities. The International Residential Code (IRC) requires a minimum slope of 1/4 inch per foot towards the drainage point. Installation 1)Drain tile or pipe shall be laid on undisturbed or well-compacted soil so that the top of the tile or pipe is below the bottom of the floor slab or the ground cover of the crawl space. The 1/2 in 12 design slope is also consistent with the authors’ findings for L/180 and stiffer deflection ratios. an inch per four feet, or a 1:48 slope ratio). By having a slope, water can easily Horizontal drain-age piping shall be installed in uniform alignment at uniform slopes. ADA compliant thresholds for roll-in or transfer showers have a maximum height of ½”. or less shall have a downward slope in the direction of flow of at least 1 in 50. However, this is more of a guideline than a rigid rule when building a deck on a slope. Roof gutters, leaders and rainwater collection piping shall slope continuously toward collection inlets and shall be free of leaks. 4558 : 1995 9451 : 1994 NOTE - Suitable transmission loss ( mvs per million square metre of wetted perimeter) for lined canal depending upon the type of lining, climatic condi­ tions shall be assumed. 1 of the Florida ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures. Roof coverings installed on low-slope roofs (roof slope < 2:12) in accordance with Section 1507 shall demonstrate physical integrity over the working life of the roof based upon 2,000 hours of exposure to accelerated weathering tests conducted in accordance with ASTM G152, ASTM G155 or ASTM G154. 709. Plumbing materials shall conform to the requirements of this chapter. 1 , the following criteria will be assumed to provide this protection. 785 L/m. The minimum size of any building drain serving a water closet shall be 3 inches. Usually 1/8" per foot is plenty for drainage, this is the same as the commonly recommended 1% slope. CODE INTERPRETATION. Oct 19, 2009 · drainage piping is upstream of a grease interceptor, the slope of the piping shall be not less than 1/4 inch per foot (2-percent slope ). for membrane roofs (built-up roofs, modified-bitumen roofs, and single-ply roofs), except coal tar built-up roofs, for which the minimum required slope is 1/8 in. (ABS) plastic pipe in IPS. 1 (701. The replacement of building sewer and building drain piping by pipe-bursting methods shall be limited to gravity drainage piping of sizes 6 inches (152 mm) and smaller. In general, a slope of about 1: 200 towards the drainage channel near the wall shall be provided in basement floors to facilitate easy flow of water towards the drain. Threaded drainage pipe fittings shall be of the recessed drainage type, black or galvanized. 3 Median Drainage 50 6. Tests requiring a pressure of greater than 100 psi (689 kPa) shall utilize a testing gauge having increments of 2 psi (14 kPa) or less. The 2009, 2012, and 2015 International Residential Code require impervious surfaces within 10 feet of the building’s foundation to have a slope of 2% away from the foundation. 1504. 704. DFU are used to calculate the drainage flow from fixtures and the required capacities of sewer service systems. However, as there is hardly any pedestrian traffic, the slope could be higher. 40, DR 22 (PS 200) and DR 24. See Chapter 1 for state agency authority and building applications. ENERGY STAR Single-Family New Homes requires permeable surfaces sloped ≥ 0. Molten lead shall be poured in one operation to a depth of not less than 1 inch (25 mm). This means that for every foot of pipe, there should be a 1/4-inch drop in elevation. BSC-CG. TABLE 702. 1 General. According to the International Plumbing Code, drainage pipes should be run with a uniform slope at the following minimum pitches: PIPE DIAMETER. value for a similar listed fixture. P3001. The drainage, waste and vent (DWV) system shall consist of piping for conveying wastes from plumbing fixtures, appliances and Underground building sanitary drainage and vent pipe shall conform to one of the standards listed in Table 702. The minimum trap size for unlisted fixtures shall be the size of the drainage outlet but not less than 1 1 / 4 inches (32 mm). Slope - Degree, Gradient and Grade Calculator Convert slopes pitch between degrees, gradients and grades. 4. To understand where this requirement is coming from and why a garage floor must be sloped, let us look at 713. Drainage fittings shall not have ledges, shoulders or reductions that can retard or obstruct drainage flow in the piping. TABLE 710. MINIMUM SLOPE. 1 Caulked Joints. A slope of less than 1/4-inch per foot will cause constant drain clogs and a slope of more than three inches will allow the water to drain without the solids. 2 Roof Drain Flow Rate. Note that I said the drain pipe must be sloped rather than the French drain. The piping of a central vacuum (fluid suction) system shall be of corrosion-resistant material with a smooth interior surface. Sep 1, 2020 · The IBC requires that the minimum roof slope be ¼ in. 15. For driveways, the minimum driveway slope for drainage may be steeper to handle larger volumes of water and prevent it from flowing towards the garage or home. Acrylonitrile butadiene styrene. 1 except that where the drainage piping is upstream of a grease interceptor, the slope of the piping shall be not less than 1 / 4 inch per foot (2-percent slope ). Drainage fittings shall be designed to maintain 1 / 4 unit vertical in 12 units horizontal (2-percent slope) grade. What is the maximum slope allowed? Good question, all I could find was this: **Slope. Mar 7, 2024 · Determine the Drainage Route: Identify the path that will allow water to flow away from your home most efficiently. 1 (2) HORIZONTAL FIXTURE BRANCHES AND STACKS a. Law is the operating system of our society. 2 1/2" or smaller. Minimum Slope. ” This needs to be incorporated into the substrate (joists, beams, decking, etc. 1)Drain tile or pipe used for foundation drainage shall be not less than 100 mm in diam. If the architect required a 1% slope and that is the slope you poured, within the 72-hour window and before the shores are Jan 7, 2021 · The rule of thumb is that you should have a quarter-inch drop for every foot of length. (Matrix Adoption Tables are non-regulatory, intended only as an aid to the code user. This code implies that all liquid-applied roof systems must have a minimum slope of 1/4:12 so that there is positive drainage of storm water to drains, scuppers, and gutters. (2) Sentence (1) does not apply to a force main. Drainage pipes fall under plumbing codes and need a minimum slope of 1/4″ every foot. 1], but if the water table is high, use waterproofing instead [406. Stacks b. Properly grade the site prior to construction to provide a slope away from the structure on all sides. 5 inch per foot away from the home for ≥ 10 feet. MATERIAL. For example, a 1-percent slope is approximately equivalent to 1 / 8 inch per foot (10 mm per m) and a 2-percent slope is approximately equal to 1 / 4 inch per foot (20 In general, buildings below slopes shall be set a sufficient distance from the slope to provide protection from slope drainage, erosion and shallow failures. 785 L. 1 SLOPE OF HORIZONTAL DRAINAGE PIPE SIZE (inches) MINIMUM SLOPE (inch per foot) 21/ 2 or less 1/ 4 3 to 6 1/ 8 8 or larger 1/ 16 For SI: 1 inch = 25. 52%; Special Considerations for Large May 15, 2018 · SECTION 1505. 3 Scuppers. Mechanical system piping capable of carrying fluids above 105°F (40°C), or below 55°F (13°C) shall be insulated to a minimum of R-2. 10. The lead shall not recede more than 1 / 8 inch (3. The provisions of this chapter shall govern the materials, design, construction and installation of sanitary drainage systems. 4 mm/m) along their entire length. (PS 140); with a solid, cellular. 9. 1 General 50 6. 7. per ft. diameters, including Schedule. This section Section 6 : HigHway drainage 6. This drain pipe slope calculator will calculate the required minimum slope, grade, and total drop (fall) of a drainage pipe over a specified length of pipe. 1 Socketed gutters shall be supported with a bracket close to the socket and another in the centre of the gutter. 1a to Table 3. [P] 1502. roofs in areas subject to 5 minute duration rainfall intensities of not more than 255 mm per hour over an average recurrence interval of 20 years (as per Table 3. DFU (Drainage Fixture Unit Values) is defined by the the Uniform Plumbing Code (UPC) and can be used to determine required drainage capacities from fixtures and their service systems. Water runoff and rain can accumulate on driveways, causing puddles and potential damage. Mar 1, 2019 · The UFC requirement is consistent with the authors’ belief that the 1/4 in 12 design slope found in the building code should be increased to provide free drainage of a roof surface. 1 except that where the drainage piping is upstream of a grease interceptor, the slope of the piping shall be not less than 1 / 4 inch per foot (2-percent slope). Generally, positive drainage requires a slope of at least 2% (1/4 inch per foot). The slope of a horizontal drainage pipe shall be not less than that indicated in Table 704. 7] (except walls supporting less than 4 feet of Mar 14, 1984 · 15 I 2527- 1984. Mar 4, 2010 · According to plumbing code, drain pipe has to be sloped a minimum of 1/4-inch per foot and a maximum of three inches per foot or vertical. The minimum slope of a horizontal drainage pipe shall be in accordance with Table 704. A common rule of thumb is the concrete slope per foot ratio, which is usually set at a minimum of 1/8 inch per foot to ensure proper drainage. 2 UNDERGROUND BUILDING DRAINAGE AND VENT PIPE. R905. They may slope to a maximum of 3” per foot, or run vertically. Apr 27, 2021 · Step 1: Floor Tile Must Slope to the Drain. Photovoltaic shingles. 1) Scope. 2]. According to IPC, the minimum slope depends on the pipe diameter: For pipes less than 3 inches in diameter, a 1/4 inch per foot slope is required (IPC Table 704. f. a. Liquid-applied roofing shall have a design slope of a minimum of 1/4 unit vertical in 12 units horizontal (2 percent slope). 08%; For Medium Pipes (3" to 6") Minimum Slope: 1/8" per foot; Percentage: 1. Oct 28, 2021 · A 4-inch drain pipe will need the same slope as a 6-inch drainpipe. This minimum slope is mentioned multiple times in Chapter 15 as “one-fourth unit vertical in 12 units horizontal (2% slope) for drainage. While a slope of 1/4 inch per foot (2% slope) is commonly recommended for adequate water runoff, it’s important to verify this requirement against local building codes and specific project needs. Roll-in showers would then also require at least 48” from the entrance of the shower to the shower drain with a slope of just ¼” per foot between the drain and the shower perimeter (i. 04%; For Larger Pipes (8" or larger) Minimum Slope: 1/16" per foot; Percentage: 0. This slope provides a balance between efficient drainage and prevention of excessive water velocity that could potentially erode pipe surfaces. In addition to the provision made in IS : 456 - 1978*, all construction joints in walls and floors shall be filled with approved sealant Jan 1, 2020 · The California Building Code (CBC) contains general building design and construction requirements relating to fire and life safety, structural safety, and access compliance. A branch shall be not less than 1 / 2 -inch (12. in the gutter shall be given in the line of brackets. 1105. DIAMETER OF PIPE (inches) MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS ( dfu) Total for horizontal branch. Parge CMUs before damp-proofing [406. 14. 1 Slope. In a stall shower, the plumbing code requires the floor to be sloped one quarter (1/4) of an inch per foot in order to carry the water effectively to the drain. TABLE 704. 3. 08%. The slope is commonly expressed in percentages as total fall per length of pipe. Sanitary Piping - Drainage Fixtures Unit Loads Maximum Drainage Fixture Unit - DFU - loads in sanitary piping systems. Valves located under concrete slabs shall be set in a pit having a least dimension of five pipe diameters with a minimum of at least 10 inches (254 mm) and fitted with a suitable cover. 2 mm), 20 minutes after the cessation of the addition of water to the deck. Excavate the Trench: Dig a trench that is approximately 6 to 8 inches wide and 18 to 24 inches deep. 4 Drainage where Embankment Height is more than 6 m 51 6. However, there are a few factors that can influence the required slope, such as the size of the pipe and the type of waste being drained. Alabama Plumbing Code 2021 > 11 Storm Drainage > 1106 Size of Conductors, VERTICAL DRAIN: SLOPE OF HORIZONTAL DRAIN: 1 / 16 inch per foot: 1 / 8 inch per foot: Apr 15, 2007 · The minimum slope for a pvc plumbing drain line is 1/4" per foot (some jurisdictions wil allow 1/8th"). Horizontal drainage piping shall be installed in uniform alignment at uniform slopes not less than 1 / 4 unit vertical in 12 units horizontal (2-percent slope) for 2 1 / 2 inch (64 mm) diameter and less, and not less than 1 / 8 unit vertical in 12 units horizontal (1-percent slope) for diameters of 3 inches (76 mm) or more. 8. 1 Piping. 16. The slope of the vent section of the horizontal branch drain shall be not greater than one unit vertical in 12 units horizontal (8. Both codes define the term positive roof drainage as: "The drainage condition in which consideration has been made 704. For content printing within Digital Codes Premium, please utilize the section level printing controls available within the Premium toolbar for each section. 1. 2. Following the site assessment, it is time to plan the slope for your pavers to ensure optimal drainage. SFM. Where scuppers are used for secondary (emergency overflow) roof drainage, the quantity, size, location and inlet elevation of the scuppers shall be sized to prevent the depth of ponding water from exceeding that for which the roof was designed as determined by Section 1611. Having a correct slope is crucial for various reasons. Firstly, a proper slope ensures effective drainage of water. For traps larger than 3 inches, use Table 709. Drainage Fixture Units (DFU) connected to building drains and sewers. 10. Justification: The ¼ inch per foot (or 2%) slope is usually sufficient for efficient drainage. 1 Building Subdrains. For SI: 1 gallon = 3. The minimum slope for hardscape or patios within ten feet of a building is 1/4″ per foot or a 2% grade The published roof drain flow rate, based on the head of water above the roof drain, shall be used to size the storm drainage system in accordance with Section 1106. ) Adopting Agency. 5 fixture units shall be allowed per gpm of flow. 1], and lap and seal all joints in waterproofing [406. The slope for wood and wood/plastic composite decks shall be not greater than 1 / 4 inch per 1 foot (1 mm per 48 mm). 5 baths. 6 Physical properties. 2 Fixtures Not Listed in Table 709. 2 Although the code specification of minimum roof slope is not based on ponding overload alone, it is important Horizontal drainage piping shall be installed in uniform alignment at uniform slopes not less than 1 / 4 unit vertical in 12 units horizontal (2-percent slope) for 2 1 / 2 inch (64 mm) diameter and less, and not less than 1 / 8 unit vertical in 12 units horizontal (1-percent slope) for diameters of 3 inches (76 mm) or more. 2 of the Administrative Code. u. Sep 12, 2023 · The slope, also known as the cross slope, refers to the angle at which the driveway surface is tilted. 4 mm, 1 gallon = 3. . It can be very hard to get the exact slope you want on a drain pipe. (1) Except as provided in Sentences (2) and (3), every drainage pipe that has a size of 3 in. Tests requiring a pressure of greater than 10 psi (69 kPa) but less than or equal to 100 psi (689 kPa) shall utilize a testing gauge having increments of 1 psi (6. The roof of a structure shall be designed for the storage of water where the storm drainage system is engineered for controlled flow. Calculating the slope of your drain pipe is easy. 2 Applicability. 3" to 6". 785 L, 1 gallon per minute = 3. The controlled flow roof drain system shall be an engineered system in accordance with this section and Section 28-113. The brackets shall be placed at not more than 900 mm centre. Jun 1, 1994 · The finished floor shall slope uniformly toward the drain not less than 1 / 4 unit vertical in 12 units horizontal (2-percent slope) nor more than 1 / 2 unit vertical per 12 units horizontal (4-percent slope) and floor drains shall be flanged to provide a water-tight joint in the floor. The sump and pumping equipment shall comply with Section 1113. Feb 27, 2022 · Standard Horizontal Drainage Pipe Slope. 1502. 2 Surface Drainage 50 6. The flow rate used for sizing the storm drainage piping shall be based on the maximum anticipated ponding at the roof drain. Building subdrains located below the public sewer level shall discharge into a sump or receiving tank, the contents of which shall be automatically lifted and discharged into the drainage system as required for building sumps. No galvanized wrought-iron or galvanized steel pipe shall be used underground and shall be kept not less than 6 inches (152 mm) aboveground. Depending on the terrain the slope could even be higher. The entire length of the vent section of the horizontal branch drain shall be sized for the total drainage discharge to the branch . 5. Dec 22, 2023 · Standard Slope Guidelines as Per International Plumbing Code For Smaller Pipes (2 1/2" or smaller) Minimum Slope: 1/4" per foot; Percentage: 2. e. 3. 1). Mechanical system piping insulation. Jan 2, 2024 · The lowest roof pitch allowed by code for any type of roof is ⅛-in-12 (0. Decks shall be sloped so that standing water will not be deeper than 1 / 8 inch (3. 5 Parapet wall scuppers. For roof slopes from 2 units vertical in 12 units horizontal (2:12), up to 4 units vertical in 12 units horizontal (4:12), underlayment shall be two layers applied in the following manner: apply a 19-inch strip of underlayment felt parallel to and starting at the eaves. BSC. Although there is no specific slope mentioned most experts will agree that a slope of 1% or higher is acceptable. This slope can be achieved using methods such as building a mortar bed or using pre-sloped shower pans. 6 Sub-surface Drains 51 6. So for for a patio that extends X feet away from your house, you would need a drop of ¼ of X, but in INCHES. Feb 3, 2012 · Architects often call for a 1% slope (1/8 inch per foot) on outdoor balconies. 1/4" per foot. This may involve digging a trench along the slope or around the perimeter of your property. The reason for this is that the drain pipe is used to transport rain water to drier areas or A drainage pipe can be installed with greater slopes because a maximum slope is not prescribed. Nov 16, 2023 · When determining how much a deck should slope, the general recommendation is to aim for a slope of ⅛” per foot. 785 L, gpf = gallon per flushing cycle, gpm = gallon per minute. This slope, according to the TCNA Handbook is called “sloped fill” or commonly known as the pre-slope. Maximum Permitted Hydraulic Load Drained to a Storm Building Drain or Sewer or a Combined Building Sewer Forming part of Article 2. 5. 2 Drainage Piping. ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures. ) to allow the moisture barrier above to have sufficient positive drainage, without ponding. Coal tar pitch is an interesting case, since it also has a very low maximum recommended roof slope (½-in-12). A showerhead over a bathtub or whirlpool bathtub attachment does not increase the drainage fixture unit value. ve za fg ao zf rw cd nr vw xf