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Unlike other aspects of building, the plumbing installation does not follow a rigid pattern. The most important aspect of the system is its proper design (and, of course, a very thorough under standing of what you are doing). You must become proficient in the basic techniques involved in measuring, cutting, and joining the pipes, and also become familiar with the various fittings available. You should also be aware of how the pipes are integrated into the building’s structure without weakening it in any way. In this section we will describe plumbing procedures and advise on how to disconnect the existing plumbing and where to start the installation. We will also explain how to extend the existing plumbing and how to organize the pipe assembly. The specific steps to be taken after these basic ones are a function of your particular design. As discussed earlier, on plumbing design, most codes require that a licensed plumber do the work. This section deals with one-family houses. Some local codes permit the owner of a one-family (and sometimes two-family) residence to do his own plumbing work with the proviso that it be inspected and approved by the “local inspecting authority.” For multiple dwellings, codes prohibit do-it-yourself plumbing. A licensed plumber is a must. The materials necessary to install the plumbing system depend on the plumbing design. What follows is a basic outline of the materials you may need. Drainage materials:
Water supply system materials: Copper piping: Type K flexible copper tubing for underground installation and Type L flexible copper tubing for aboveground installation Pressure and temperature relief valve at your hot-water heater outlet Outside water faucets (freeze-proof if you live in a cold climate) Valves and fittings, as needed: shutoff valves, unions, tees, etc. Materials required to aid in the installation of the system:
Tools: The tools needed for plumbing installation vary with the pipe material you are using. Regardless of materials, however, you will need the following carpentry tools for cutting the woodwork:
In addition to these tools, you should have an adjustable wrench or a wrench set for tightening nuts when installing the fixtures. A ladder is also handy, since a lot of the plumbing work takes place in the ceiling and hard-to-reach places. If you want to avoid a lot of bending, use a work bench instead of the floor to assemble the pipes. The tools required for the assembly of copper piping are:
Cast-iron piping requires the following tools:
Following is a list of tools needed for the installation of plastic piping:
The plumbing installation takes place in two stages: the rough stage, when all the normally concealed pipes and fittings are located and assembled, and the finish stage, when fixtures are installed. Before either one of these stages can take place, however, you must disconnect the old fixtures. DISCONNECTING OLD FIXTURES The very first step is to find the shutoff valve for every line where a fixture is being removed. These valves are generally located at the base of the pipe serving the fixture. Older houses may have one valve that controls more than one fixture. These are often located in the basement. Occasionally you may find shutoff valves hiding in nearby closets, or concealed inside walls or chases, with handles protruding. Once the valves are shut, open up the faucets and drain all water. The supply pipes in lavatories and sinks are disconnected by removing the un ions with pipe wrenches. There are instances where the supply piping may be attached to threaded faucet stems underneath the basin. Loosen up the nuts with a basin wrench. With the aid of two pipe wrenches, detach the drainage pipe by loosening up the trap’s slip coupling. The sink can now be taken off and set aside. Stuff a rag in the drainage pipe to prevent sewer gases from entering the space. To remove toilets, start by closing the shutoff valve located near the base of the water flush tank. Flush the toilet and make sure there is no water left. If you have a two-piece toilet (with a separate tank and bowl), disconnect the tank from the bowl by loosening the bolts that hold the sections together. The toilet base is then detached by unscrewing the nuts capping the bolts on either side of the base. The last step is to break the wax seal between the toilet base and the floor by gently rocking the toilet base. The base can then be lifted and set aside. Don’t forget to block the drainage pipe with a rag. Tubs are trickier. The connections are often in side the wall at the head of the tub or under the floor. In such cases be prepared to restore tiles, wallboard, plaster, and paint finishes. You will need to remove portions of these finishes to get to the pipes. Again, with the aid of a pipe wrench, the drain-overflow assembly is set apart by loosening up the slip couplings. Disconnect the un ions or simply cut through the supply risers. At this point, you should cap all disconnected pipes. This will allow you to turn on the water service to other areas of the house which are still in use. Now go back and check for leaks at these caps. = = = BASIC SKILLS: HOW TO MEASURE PIPING Measure the face-to-face distance the pipe must travel between fittings. To this distance add the depth that the pipe must travel into each fitting. (Make sure to add this quantity to both ends.) Let’s say that the distance between fittings is 11” and the distance the pipe will go into each fitting is 1/2”. The total required length of pipe will be 12”. HOW TO CUT and JOIN PIPE The method of cutting and joining pipes varies with each material. Regardless of material, how ever, make a few practice cuts and joints before going ahead to the actual installation to get the hang of the material. Cast-iron pipe: Joining cast-iron pipe may vary with the local code requirements. Most codes no longer require leaded joints, which are cumber some and difficult to do. Cast-iron pipe is available in the hub-and-spigot type. It consists of a section of pipe with one end having a larger diameter than the other. The larger-diameter end is called the hub. The opposite end has a slight ridge and is called the spigot. These ends are designed to fit inside each other. The hub is always located at the end facing up (receiving the flow of the drainage). The spigot end fits inside the hub of the section underneath. Cast-iron pipe is also available in a no-hub type. SELL Cuts in cast-iron pipe are made by means of a cold chisel or a hacksaw, depending on the thickness of the pipe. (There are two thicknesses of cast-iron pipe, a heavy one for exterior use and a lighter one for interior use.) Chalk-mark the length to which the pipe must be cut. Place a piece of wood on the floor and lay the pipe over it. If the pipe is lightweight, use a hacksaw to make a shallow cut all around the pipe. Tap the pipe with a hammer until it breaks. A hacksaw won’t work when using heavy pipe. Instead, score the pipe at the chalk line with a cold chisel. The first cut should be a light one all around. Then continue chiseling progressively harder until the pipe breaks (3). To join no-hub pipe, slip the neoprene gasket over the end of one pipe and the metal band over the end of the other pipe (or fitting) (4). Bring the two ends together and slip the gasket over the joint. The next step is to slip the metal band over the gasket. The connection is completed by tightening the clamps in the metal band with a screwdriver (4). These clamps hold the joint together. An added advantage to the no-hub fit tings is that they can be easily taken apart without damage. Copper tubing: Copper is considerably easier to cut and join than cast iron. To cut copper tubing, chalk-mark the desired length. Copper can be cut with a hacksaw and a jig or with a pipe cutter. Regardless of the method, the important thing is to get a square cut. If you are using a pipe cutter, place the pipe on a vise and the cutting blade of the cutter on the chalk mark. Rotate the cutter around the pipe at the same time that you are tightening the cutter’s handle. The cut pipe is likely to have burrs, which must be removed with a file. Before the pipe can be soldered, its ends as well as the inside of the fitting must be cleaned with steel wool. It is wise at this point to check for any dents in the pipe. Remember that the pipe must be perfectly round if the joint is to be successful. With a brush, apply a coat of flux to the inside of the fitting and the outside of the pipe you have just cleaned. The fitting is then slipped on and turned a few times in order to spread the flux evenly all around. Any excess flux should be removed. The soldering process starts by heating the fit ting with a torch. When hot, solder is applied to the edge of the fitting all around the joint, sealing it. (Capillary action allows the melted solder to penetrate into the space between the pipe and the fitting.) Remove the heat after the connection has been filled. Wipe away any surplus solder. (Be careful not to burn yourself.) While the solder joint is cooling, prevent the solder seal from being bro ken by making sure that the pipe and fitting aren't moved. Plastic piping: Plastic is by far the easiest material to cut and join. Cutting plastic pipe can be done with a hacksaw, a handsaw, a power saw, and sometimes even a pocketknife. (Make sure that the saw is fine-toothed.) Here again, a square cut is important. This can be easily done by using a jig. Once the pipe is cut, any burrs should be removed with a file. Plastic pipe is joined by means of solvent. Before it can be applied, however, the inside of the fitting and the outside of the pipe should be cleaned with emery cloth. The solvent is then applied on both the outside of the pipe and the inside of the fitting with a bristle brush, covering the entire area which makes up the joint. It is important to get the correct solvent for the type of plastic pipe you are using. The easiest way to avoid confusion is to purchase the solvent at the time you purchase the pipe. Slip the fitting onto the pipe as far as it should go. Press it against the pipe, and turn it (about a quarter of a turn) to ensure the even distribution of the solvent. Hold the joint together for a few seconds and then remove any excess solvent. Do not move the joint until it has had sufficient time to set. Compare this procedure with that for copper or cast-iron piping and the reason why plastic pipe is gaining in popularity becomes obvious. = = = EXTENDING PLUMBING TO A FIXTURE If you only need to add a few fixtures, try to use the existing pipes wherever possible. Start by locating the new fixtures with chalk or a crayon. Take a look around that area to assess where the closest drainage and supply pipes are. Cut away the finish wall surfaces to the edges of the nearest studs. Avoid cutting the studs or floor beams. Where new plumbing needs to be run under floors you will have to drop ceilings to allow for the pipe runs. Allow yourself enough room to work. Try to visualize the new piping and new fixtures in place. The next step is to locate the traps. In the case of lavatories or sinks, you need to locate the trap height on the wall. From the, top of the trap run an imaginary line to the soil stack, making sure the pipe pitches downward. Where this line hits the trap, mark an X. (The bottom of the trap shouldn't be lower than the connection to the stack. Otherwise, water will be siphoned from the trap.) Position the T connection to the soil stack at the X location. Mark the top and bottom of the fitting on the soil stack. To prevent damage to the piping, secure both sides of the pipes next to the cuts. The next step is to join to the existing pipes by cutting into them (make sure that you have drained the pipes first). Using a pipe cutter, cut out the section of the stack. Join the new fitting with hub- less connectors. Toilets have built-in integral traps; showers and tubs have the traps at or in the floor below. Toilet traps should connect directly into the soil stack as described earlier. To hook up shower and tub traps, follow the basic procedure described for lavatories. Positioning the fittings for the supply pipe isn't as critical as for drainage pipes. It’s a good idea, however, to pitch the pipes slightly down ward back toward the supply risers just in case you need to drain the system. The procedure for cutting and fitting new supply and vent pipes isn't altogether different from the procedure for drainage pipes. You will need to cut a section of pipe and install a tee to bratich into the new line. If the original supply pipe is galvanized or other material, you need to use adapters to extend pipe with copper. Here are a few things to keep in mind while installing the hot- and cold-water supply pipes: Hot- and cold-water pipes run side by side approximately 5” apart. Where the pipes must cross, be certain that they are still an adequate distance apart. Where possible, insulate all such branch supply piping with fiberglass pipe insulation. Always provide a shutoff valve at each fixture supply line to facilitate repairs. It is also a good idea to pro vide each branch pipe leading to a kitchen, bathroom, or laundry room with a shutoff valve. This can prove helpful in the event that the water has to be cut off from an entire area at one time; it eliminates the need to close each individual fixture valve. Don’t forget to pitch all horizontal branch pipes down toward the stop and waste valve you have already installed at the lowest point in the system. Drainage of the system may otherwise be impossible. Hot-water supply pipes are usually located to the left of the fixtures (looking at the fixtures head-on). Air chambers must be installed (usually in the wall behind the fixture) above each supply pipe. This is easily done by putting a tee at the top of the vertical supply pipe. A capped length of pipe approximately 12” in length is inserted in the top of the tee and becomes the air chamber. When the drainage and venting systems have been installed and until such time as the fixtures are hooked up, debris must be prevented from entering the pipes. This can be done by plugging up all the pipe outlets temporarily with rags. This also prevents poisonous gases from the house sewer from backing up into the house. In addition, check for any unused openings in the tees or other connections. If there are any, plug them up with a cap and nipple. ADDING A NEW WASTE STACK and DRAINAGE SYSTEM Your renovation may include an extension with plumbing for a kitchen or bath. More often than not, the existing soil stack will be too far from the new plumbing. The best solution is to install a new waste stack (secondary soil stack) which in turn is connected to the house drain. The house drain can be extended by tapping into it at the existing cleanout. Remove and replace the existing cleanout with a new length of pipe as required. A new cleanout is then installed at the end. With the aid of your plans and templates or dimensions supplied with the fixtures, measure and mark with chalk on the extension floor the location of the new fixtures, their drains, and hot- and cold-water lines and where the waste stack punctures the floor and walls.* Cut a small hole (as marked in chalk) where the waste stack penetrates the floor (or if you have a multistoried ex tension, the highest floor where the extension has plumbing). Once the hole is open, take a look to see if there are any structural members in your way. Should you encounter joists or beams, you will have to reposition the stack accordingly. If there is no structural interference, drop a plumb bob to the floor below and mark the exact location where the waste stack will fall. Repeat this procedure for as many floors as necessary to establish the stack run. To determine where the waste stack will pass through the roof, plumb up to the roof from the cutout on the highest floor. Drill a small hole to see if any rafters are in the way. If there are no rafters in the way, you have just established the complete stack run. You can now go back and enlarge the holes (make them slightly larger than the diameter of the stack pipe). If the extension has a toilet, drill a small hole in the floor where the drain will be located to determine if there is any structure in the way. (Water closets should drain directly into the waste stack.) If there is no problem, enlarge the hole and position a sanitary tee and elbow together. Hold them temporarily in place with braces directly beneath the two openings provided. *If you build an extension that has plumbing, remember to provide access to the crawl space through either the foundation wall or a trapdoor. The waste stack will go down through the basement or crawl space to join the upper end of the building drain. Don’t forget that the building drain should have a minimum rise of 1/4” per 1’ (or as required by code). Install a cleanout (a sanitary Y branch with a cleanout plug) where the soil stack and the building drain come together. Check to make sure that the sanitary Y is plumb and directly underneath the location of the waste stack. You can now start assembling the waste stack from the bottom up. The first run of vertical pipe is connected to the sanitary Y (cleanout). If the material of the house drain is different from that of the waste stack, you will have to use an adapter. Otherwise, continue upward with the stack until it reaches the point where it connects to the first-floor sanitary tee; some pipe cutting will be required. The tee can have one or more side outlets, depending on the number of branch lines it must receive. The sanitary- tee connection between the toilet and the waste stack, which had previously been temporarily held in place, can now be joined to the waste stack. The waste stack continues its run to the roof by joining successive lengths of pipe. Once it reaches the roof, it should extend through the roof and be carefully flashed. On its way to the roof, branch pipes connect into the stack as required by the design of the drainage system. Whenever the waste stack is brought up to a level where branch waste lines occur, they should be connected to the stack before it's built up any further. The branch lines are located by measuring, cutting, and joining pipes until they follow the path required between the fixture drains (as indicated by the chalk mark) and the waste stack. These runs will sometimes occur in side a wall (as in the case of sinks) and other times under the floor (as in the case of bathtubs and water closets). To allow for free passage of waste, avoid sharp bends. Never use a right-angle pipe fitting in bends or in runs of drainage pipe. Make sure that every fixture is supplied with a trap. Double-check all horizontal drainage lines to be certain that they are pitching at a minimum of 1/4” per 1’ (or as required by code). CONNECTING VENTS The venting network is an integral part of the drainage system and it's installed at the same time. (When installing waste lines, make sure to leave Y’s to allow the connection of vent lines later on.) Because they function by gravity, drain age lines pitch down toward the waste stack. In stead of letting these lines terminate at the level of the fixture trap, they are extended upward above the trap and are hooked to a vent riser. When continuation of the fixture drainage pipe upward is impossible, a vent line is connected to a branch line as close to the fixture as possible. The connection between the drainage line and the vent is done with a Y or T-Y to facilitate waste going in one direction. These connections generally occur inside the walls. A horizontal vent branch is then installed to join the various fixture vents. Horizontal vents should always pitch up toward the vent stack to prevent waste in the drainage lines from entering the vents. The vent branch is then connected to a vent riser. Its path through the house is parallel to that of the waste stack, until it's either connected to the waste stack (above the level of the highest fixture) or continues its run directly to and through the roof. The procedure for locating the vent stacks is similar to that for the waste stack. You may need to jog pipes around to work around the structure of the building. The vent lines for a particular area should be installed at the same time as the drainage lines. EXTENDING: A WATER SUPPLY SYSTEM The techniques involved in installing the water supply system are essentially those employed in installing the drainage system. The primary difference between the two involves size. Waste and vent pipes are large and often can't be drilled through studs. They can never be drilled through joists. Instead, dropped ceilings or soffits are generally built around them. Supply pipes, on the other hand, are often installed in studs by drilling holes. Drainage pipes can serve as guides for the location of the hot- and cold-water supply lines. The steps required for aligning and erecting the supply pipe assembly are similar to those for the drainage pipes (of course, the actual connection work will vary with the pipe material). = = = THE PIPES and THE STRUCTURAL FRAME The piping network weaves its way through the structure of the house and is supported by it. It is essential that the structural strength of the frame not be diminished by the holes cut in its members. Cutting away at the house frame to make room for the pipes must not alter the load-carrying capacity of the frame. Nobody wants a sagging floor or, worse yet, a collapsed one. Here are a few pointers to keep in mind: • When drilling holes or cutting notches through the studs or joists, the cut should never exceed one-quarter of the total depth of the member. • Holes drilled through joists should be centered between the top and the bottom face of the joists or studs. • If a large notch is absolutely necessary in a joist, beef up the joist with additional wood or steel plate or nail in and attach a second joist. • Wet walls are usually framed out 2” X 6” to accommodate pipe thicknesses (particularly waste pipes). • When studs are too small to accommodate the pipes, the walls need to be furred out. This is done by attaching another layer of studs (either 1” x 2” or 2” x 4”) to those already in place. Keep in mind that notched studs should be reinforced with a steel plate. • Sometimes pipes (particularly drainage pipes) have to be run under the floor to avoid interference with existing joists. If this is the case, the ceiling below is dropped to accommodate the pipe runs. In older buildings, sometimes there is a “false” floor space or ‘fill,” which is occasionally large enough to contain new drain age piping. • A steel plate can be added to the side of a notched stud to add to its strength (-4). = = = = PIPE SUPPORTS: Pipes are heavy slender elements that have to span large distances. To prevent their buckling and sagging, supports are provided. When a pipe is traveling horizontally through a wall, the support is provided by studs. At other times the run does not occur within the structure (as may be the case in the basement ceiling) and pipe hangers and other clamping devices must be used. Horizontal pipes should be supported at least every 6’ to 8’. Larger piping such as steel is generally supported every 10’. Cast-iron piping should be supported at or near every fitting and a maximum of every 5’ on straight runs. Vertical runs of 1” pipe need to be supported at every floor. The plumbing supplier can provide you with additional information regarding the spacing of supports for the specific type you are using and the various supports available. = = = To plot out the route the pipes must take, start by locating the existing hot- and cold-water mains. Take a look at the proposed location of the fixtures. The next step is to figure out the easiest path for the branch pipes to take in order to connect to the fixtures (try to minimize bends and cutting). Areas are cut out for each pipe according to its installation priority. That is, main stacks and supply mains will be installed before branch pipes. Do only enough drilling through wood work to deal with the specific pipe run you are installing. If you cut the woodwork for all the plumbing at once, inaccuracies between the original layout and the actual pipe assembly might get you in trouble. Be aware that there is a limit to how much wood framing you can cut without causing structural damage. For basic guidelines on supply pipe installation, see the section “Extending Plumbing to a Fixture.” Remember that pipes have to be properly secured within the structure of the building. FINISHING THE INSTALLATION The finish installation takes place once all wall, floor, and ceiling finishes are up. It consists of hooking up the fixtures (water closets, tubs, lavatories, sinks, etc.) to the plumbing system. The installation of the fixture varies with both the fixture and its manufacturer. As a general rule, manufacturers supply detailed instructions and recommendations for the installation of their products. Get all the literature and help that you can from them. They’re probably the best avail able source. Here are a few items to keep in mind while doing the finish installation: WATER CLOSETS: To make a watertight seal between the bowl and the floor, turn the bowl upside down and apply putty to the outside rim. Then place a ring (rubber, putty, or wax designed for this purpose) around the drainage opening. Turn the bowl right side up and move it slightly until you position it over the floor flange.* Ease the toilet over the flange bolts. Press down on the bowl to make the putty spread evenly. Make sure the top of the bowl is level and that there is no rocking before you tighten the nuts. Do this care fully, without overtightening, to avoid cracking the bowl. You can now install the tank over the bowl as per the manufacturer’s instructions. *The floor flange fits over the top of the water closet drain. It acts as an adapter between the bend and the toilet base. == == HOT-WATER HEATERS Place the hot-water heater in its intended location. Shut off the valve at the water supply main. With the aid of a tee, split the water supply main in two. One branch is connected to the water heater (by means of a union) and becomes the hot-water supply main. The other branch bypasses the water heater and becomes the cold-water main. Install a shutoff valve on both inlet and outlet pipes (-1). Otherwise, you will not be able to stop the water flow into the heater in the event of a break down or a necessary repair. The next, very important step is to provide the water heater with a temperature and relief valve (unless the heater comes already equipped with one). The relief valve is a safety measure against an explosion of the water heater (or boiler) due to a buildup of pressure. In addition to being connected to the heater, this valve is joined to a 1/2” relief or blow- off pipe directed toward the floor (-2). The purpose of the pipe is to permit the release of any excess water and steam in the event the relief valve “pops” or “blows.” It must be directed down toward the floor to prevent anyone’s getting hit by a discharge o high-pressure hot water. == == SINKS and LAVATORIES: Unless it rests on a cabinet or pedestal, the sink or lavatory is hung from the wall. In order to do this, a 1” X 6” piece of wood approximately the length of the sink is nailed to the studs. A metal hanger is then bolted or screwed to this board. Before the wall finish is applied, notch the studs to accommodate the thickness of the wood. TUBS: If you have a custom tub, keep in mind that the floor of the tub should slope toward the drain. Manufactured tubs come built this way. CONNECTIONS: For typical hook ups of fixtures to water supply and drainage systems. Next: Modifying the Heating Equipment |
