General Installation Instructions

1. Vertical Piping: 
1. Secure vertical piping at sufficiently close intervals to keep the pipe in alignment and to support the weight of the pipe and its contents. Support stacks at their bases and at sufficient floor intervals to meet the requirements of local codes. Approved metal clamps or hangers should be used for this purpose. 
2. If vertical piping is to stand free of any support or if no structural element is available for support and stability during construction, secure the piping in its proper position by means of adequate stakes or braces fastened to the pipe. 
2. Horizontal Piping, Suspended: 
1. Support horizontal piping and fittings at sufficiently close intervals to maintain alignment and prevent sagging or grade reversal. Support each length of pipe by an approved hanger located not more than 18 inches from the joint. 
2. Support terminal ends of all horizontal runs or branches and each change of direction or alignment with an approved hanger. 
3. Closet bends installed above ground should be firmly secured. 
3. Horizontal Piping, Underground: 
1. To maintain proper alignment during backfilling, stabilize the pipe in proper position by partial backfilling and cradling. 
2. Piping laid on grade should be adequately secured to prevent misalignment when the slab is poured. 
3. Closet bends installed under slabs should be adequately secured. 
4. Installation Inside the Building: 
1. Installation suggestions. According to most authorities and plumbing codes, it is sufficient to support horizontal pipe at each joint, i.e. 5' pipe should be supported at five foot intervals, 10' in length may be supported at ten foot intervals. Supports should be adequate to maintain alignment and prevent sagging and should be placed within eighteen inches of the joint. 

             When the system is filled with water, sufficient beam strength is provided by cast iron soil pipe to carry the load with hangers every ten feet. Any of the horizontal supports or clamps illustrated in Figures 1 and 2 may be used, depending on conditions or what is regarded as essential by the contractor, architect or engineer. Whatever method of support or clamp is used for the horizontal line, care should be exercised to make certain that the line has a proper grade (1/4 inch or more per foot). 

             Hangers may be fastened to wood members or beams with wood screws, lag screws or large nails. For fastening to "I" beams, bar joists, junior beams or other structural members, beam clamps or "C" clamps may be used. Fasteners for masonry walls may be expansion bolts or screws, or where a void is present, the toggle bolt may be used. Studs shot into the masonry by the explosion method may also be used. Along a wall, a bracket made of structural members or a cast bracket may be used. 

             Adequate provision should be made to prevent "shear". Where components are suspended in excess of eighteen (18) inches by means of non-rigid hangers they should be suitably braced against movement horizontally, often called sway bracing. Examples of sway bracing are illustrated in Figures 3 and 4. 

Horizontal Installation of Large Diameter Pipe.

Suggested Installation of Horizontal Fittings.

1. Hangers should be provided as necessary to provide alignment and grade. Hangers should be provided at each horizontal branch connection. Hangers should be adequate to maintain alignment and prevent sagging and should be placed adjacent to the coupling. By placing the hangers properly, the proper grade will be maintained. Adequate provision should be made to prevent shear. Where pipe and fittings are suspended in excess of eighteen inches by means of non-rigid hangers they should be suitably braced against movement horizontally, often called sway bracing. Refer to Figures 3 and 4 for illustrations. 
2. Closet bends, traps, trap-arms and similar branches must be firmly secured against movement in any direction. Closet bends installed above ground should be stabilized. Where vertical closet studs are used they must be stabilized against horizontal or vertical movement. In Figures 6 and 7 see illustration for strapping a closet bend under a sub-floor and how a clevis type hanger has been used to an advantage. 
3. When a hubless blind plug is used for a required cleanout, the complete coupling and plug must be accessible for removal and replacement. 
4. The connection of closet rings, floor and shower drains and similar "slip-over" fittings and the connection of hubless pipe and fittings to soil pipe hubs may be accomplished by the use. of caulked lead and oakum or compression joints. 

Figure 5 - Large Diameter Pipe 

Figure 6 - Cross Section View of Closet Bend Showing Flange Properly Secured

Figure 7 - Method of Using Hanger for Closet Bend 

Seismic Restraints

1. Brace all pipe 2" and larger.

Exceptions:

Seismic braces may be omitted when the top of the pipe is suspended 12" or less from the supporting structure member and the pipe is suspended by an individual hanger.

2. Vertical Piping Attachment - 


Vertical piping shall be secured at sufficiently close intervals to keep the pipe in alignment and carry the weight of the pipe and contents. Stacks shall be supported at their bases and if over two stories in height at each floor by approved floor clamps. At vertical pipe risers, whenever possible, support the weight of the riser at a point or points above the center of gravity of the riser. Provide lateral guides at the top and bottom of the riser, and at intermediate points not to exceed 30' 0" on center.

3. Horizontal Piping Supports - 


Horizontal piping shall be supported at sufficiently close intervals to prevent sagging. Trapeze hangers may be used. Pipe, where top of the pipe is 12" or more from supporting structure shall be braced on each side of a change of direction of 90 degrees or more.

4. Traverse bracing 


40'- 0"o.c. maximum spacing unless otherwise noted. One pipe section may act as longitudinal bracing for the pipe section connected perpendicular to it, if the bracing is installed with 24" of the elbow or tee of similar size.

5. Longitudinal bracing 


80'- 0"o.c. maximum spacing unless otherwise noted.

6. Miscellaneous 

WHERE MULTIPLE SHIELD AND CLAMP JOINTS OCCUR IN A CLOSELY SPACED ASSEMBLY (I.E. FITTING-FITTING-FITTING, ETC.) A 16 GAUGE HALF SLEEVE MAY BE INSTALLED UNDER THE ASSEMBLY WITH A PIPE HANGER AT EACH END OF THE SLEEVE.¹
Method of supporting "multi-fitting" installations 
(Hanger spacing 10 ft. max)

FIG. 8 - FOR SEISMIC BRACING ONLY

NOTE: Seismic braces may be installed at either hanger, braces at both hangers are not required. 

¹Reprinted with permission of the Plumbing & Piping Industry Council, Inc. 

Vertical Piping.

             Vertical components should be secured at each stack base and at sufficiently close intervals to keep the system in alignment and to adequately support the weight of the pipe and its contents. Floor clamps, sometimes called friction clamps, are required for vertical piping in multistory structures in order for each floor to carry its share of the load. Figures 11 and 12 show some typical brackets or braces for vertical piping. Figure 13 shows a method of clamping the pipe at each floor, using a friction or floor clamp. 

             If vertical piping is to stand free of any support or if no structural element is available for support and stability during construction, secure the piping in its proper position by means of adequate metal stakes or braces fastened to the pipe.