Jeff's DIY

Advice on doing your own diagnosis and repair

Advice from the book Can I Do It Myself?

Plumbing Projects

High pressure water.

Home water systems may come in copper, pex (plastic tubing), PVC and possibly old galvanized pipe. If PVC is used inside the house, it should be schedule 80 PVC for cold water and CPVC for hot water. PVC is probably the easiest to learn, but pex is also easy and requires fewer steps. The tradeoff is that PVC requires only a saw for cutting pipe to length, whereas pex requires crimping tools. However, once you have the crimpers, pex is easy to install. A single line is cut to length and runs all the way from a spare port on the manifold to the faucet. A copper ring goes on the tube, the tube is slipped over the fitting and the ring is crimped down to seal the tube onto the fitting. A go-no go gauge is used to check the crimp for the correct final ring diameter. The manifolds usually have individual valves for each port, so there is no need to shut off the supply. Just connect to the port and then open the valve. If there are no spare ports on the supply manifold, you can tee into an existing line in the house (after closing the valve to that line), provided you are not supplying something large, like a tub or shower (you should be using a reducing tee).

PVC is run with straight pipe and elbows, etc. Straight pieces are cut from a ten foot length available at any home improvement store. Use a hack saw or just about any saw to cut the straights, taking care to clean the cut end of plastic debris from the saw cut. The fittings are glued together with special PVC glue. I usually start at the business end, find a fitting that connects to the faucet or appliance being supplied and work my way through the house with the appropriate size PVC for the item being supplied, getting all of the straight cuts done and slipping everything together before getting the glue out. Pipes should be cut to lengths that assume they will push fully into the slip fittings. Once the run is made up to the point of tying into the main supply, I prime and then glue the pieces together firmly, one at a time, starting at the business end. Don't use much glue, if any, on the female part of any connection or you will have glue buildup inside the pipe. I let all that dry for a day before shutting off the supply and hooking the new line in. If there is more glue in that step, plan to leave the system off but open at the business end (to allow any seepage out without building pressure) and let it dry for at least a few hours-preferably overnight. You don't know for sure how long it has to set until you have a connection come apart under pressure. That can be quite messy. Once dry, restore the supply pressure to the home.

Copper pipe is similar to PVC, except the connections are made using acid core solder using a torch. You can use a hack saw to cut the straights, but a copper pipe tool is inexpensive and much preferred. The mating surfaces must be cleaned of all oxidation using emery cloth. A thin coat of flux is applied and the joint is slipped together and held with a fixture or clamp. The torch is used to heat the joint until the solder melts and wets into the mating surface and overflows to the outer edge of the joint. Allow to cool before touching or unclamping. Once the new line is tied into the system and pressure is restored, run a few gallons of water through before using it for drinking, to get most of any residue out of the pipe.

Galvanized pipe is not used much for water these days, but you may have an old installation to repair or add to. This approach uses fittings and pipe cut to length and then threaded with a pipe threading machine. Pipe suppliers have these machines in their stores, so you need to show up with the correct lengths you want. Assume the threaded pipe will thread in about 2/3 of the way into the female fitting. Apply sealant to the threads and thread the pieces together one at a time starting at the business end using two pipe wrenches. When you get to the supply, you will need a coupler to connect. As you can imagine, it is nearly impossible to add such a circuit to an existing home without opening the walls, because you cannot swing pipe wrenches inside a wall. If you really need to add a circuit and don't want to open the walls, you may be able to do it by using couplings at both ends; however, additional couplings will add more potential leak points, as they are more likely to leak than a sealed, threaded joint. If you are adding pipe in a more open area, such as a crawl space or attic, make sure to tie down the pipe using straps to prevent potential bending.


Gas line plumbing.

Gas uses black iron pipe of an appropriate size. Use 3/4" for an oven or furnace and 1/2" for smaller applications, such as a gas fireplace. The rest is identical to galvanized pipe discussed above, except the thread sealant may be different. Your local home improvement store can tell you what sealants are approved for use in your area for either application. Note that many areas require a license to install gas plumbing, for obvious reasons. A gas leak can be quite disastrous. That said, natural gas supply is very low in pressure, so well-sealed threaded connections are not likely to ever leak. A coupling or other compression-based seal is more likely to leak, especially if the mating surface is damaged or warped. The flange surfaces of these fittings should be inspected carefully before being put together and tightened well. Sealant is required on any brass taper fittings, as with the black iron pipe. As with any plumbing job, a leak check should be performed when the supply valve is opened to a new circuit. In the case of gas, this is a critical step. Professionals use sniffers for this, but car wash or dish soap mixed with some water and put into a spray bottle works, as long as this method is legal in your area. Spray all joints, one at a time, and look very closely for bubbles forming. Bubbles will come out of the sprayer onto the fitting, but any new bubbles forming (even very small ones) are a sign of seepage. If you see any seepage and are not sure why the joint didn't seal, shut off the supply and call in a pro to check your work. As with galvanized pipe but more importantly for gas pipe, make sure the circuit is strapped down to prevent bending movement that could cause the threads at a joint to snap.


Water heaters.

Water heaters are fairly easy to replace; but, in some areas, you have to be licensed to make the gas connection. If there is an inlet valve, and there usually is, shut that off but leave the main supply to the house open, so people can use the bathrooms. There should be a gas valve near the water heater to shut off the gas. Screw a garden hose to the drain valve and guide it to the closest drain to empty the water heater. Disconnect the gas and both water lines. Be prepared for some water to come out of the open pipes. This can be reduced by opening a hot water faucet high in the home prior to disconnecting the hot water pipe from the unit. Disconnect the relief valve pipe as well. Make sure there is nothing else holding the unit in place and move it away from the connections. There will still be a little water in the unit, which can make it heavy. Use a dolly to remove it from the home and bring in the new unit. Move the new unit into place. If the size of the new unit is different, you may need to re-plumb the piping. Use appropriate sealant when making the new connections. Teflon tape is used for tapered water fittings, but the water fittings are usually flex lines, and they may have rubber washers. You can supplement with the Teflon tape on the threads, if you like. I use about five trips around the threads to get enough Teflon on them. Get the connections good and tight. The gas connection is usually made with a flex line, but the fitting may be tapered or compression. Use gas sealant on the threads for a tapered fitting. Open the gas valve and check for leaks, as I explained under gas plumbing. Reconnect the relief valve pipe. If the relief valve on the new unit is located differently, you may need to re-plumb that line. That line is only there to lead water out of the home or into a drain in the unlikely event of an overpressure of the supply that threatens to burst the tank. Attach any supports as necessary to hold the unit in place-states, for example California, may require attachment to the home structure. Re-open the inlet and check for leaks. Allow the tank to fill before rechecking for leaks. While it is filling, close any hot water faucets you may have opened in the home. Once the tank is full, attach a garden hose to the drain, and run some water through to make sure it comes out clear. If not, let it run until it comes out clear. Also open the relief valve briefly to check for leaks in the relief pipe. Follow instructions on the unit to fire it up. Open a faucet close to the new unit and check again to verify that the water is clear. Set the unit temperature as desired. Once the water is hot, take a shower.


Filters and softeners.

To soften or otherwise filter or condition the water for your entire home, you must break into the supply line downstream of the outside spigots but upstream of the line to the water heater. In areas with poor quality or hard water, builders usually include a convenient place to add a conditioner, if they don't actually include a conditioner with the house. I have found that it is worth the extra expense of using flex lines rather than hard piping these appliances. Find appropriate fittings to go from the home interface to one inch flex lines and make sure your flex lines will interface the appliance. Get the appliance ready using instructions from the manufacturer and connect the flex lines to the unit. Shut off the house supply line, and add the new fittings. If you aren't sure which side is the supply, crack the main valve open just a tad momentarily to see which line should go to the inlet of the appliance. Connect to the flex lines, tighten, open the supply valve, and check for leaks. Follow the remaining manufacturer's instructions to activate the new appliance for use.


Low pressure water.

Drains are obviously low in pressure, but leaks still cannot be tolerated. I actually find these low pressure systems to be more challenging than the water supply systems. The reason is that drains require proper venting and slopes to ensure proper function. Codes for home drain plumbing are fairly universal, though I have seen some special requirements in some areas. Be sure to check your local codes before modifying or installing new drain circuits. Older installations may use galvanized or other iron pipe for drains, but virtually all modern sanitary sewage in the home uses PVC. This is usually all you can find in your local home improvement store. Plumbing from an actual sink drain may be of a lower thickness plastic that uses a flange and nut to compress the flange between the two sides of the connection. These kinds of fittings are usually used for sink traps to allow easy access to the trap for cleaning or retrieving something valuable. Make sure you get the flange seal on in the right way-the flat side should face the nut. Slip the seal onto the straight pipe with the nut and insert that pipe into the female-threaded side. There should be at least an inch or more of pipe going into the female side. Tighten and check for leaks by running the faucet. The PVC from the drain (usually 1 1/4" or 1 1/2" diameter to match the trap size) should angle down slightly, if possible (or at least level), from the trap and have a vent in the wall up to the roof. A drain that cannot pass a vent line to the roof, such as a sink installed in a kitchen island, uses a special vent inside the cabinet. This should be installed as high as possible in the cabinet.

New drain circuits must be properly vented and use gravity slopes as specified in your local code. 1/4" per foot is a pretty common slope code, though a lesser slope may be allowed for the main sewer lines. All drains must have a trap and vent to break suction and allow the drain to function properly. A toilet has the trap built-in and uses a wax ring to seal to a flange on the 3 or 4" drain pipe. The vents are usually made by using a tee in the wall behind the drain to allow the waste to go down into the main sewer line and a line of the same size going up to the roof to allow air into the line downstream of the trap. A drain that is used infrequently may dry up and allow air from the sewer to enter the home. Make sure to use every drain at least once a month to keep the trap full.


Faucet, sink, and toilet replacement.

Indoor faucets are easily replaced if access is good. If there are relatively new supply valves at near the faucet, shut them off. If they are missing or old, I shut off the entire house supply and open the old faucet valves. Disconnect the flex lines from the faucet, but keep a towel handy to catch the bit of water that will be released. Remove the nuts or other fitting that holds the faucet to the sink and remove the faucet. Reverse the procedure to install the new faucet, making sure to seal the flex lines according to the faucet manufacturer instructions. Most of these are compression fittings with rubber washers, but any taper fittings will need some Teflon tape on the male threads.

Replace a sink drain or installing a drain on a new sink, is fairly easy. Disconnect the trap and remove any stopper connected to the back of the drain or remove the disposal from a kitchen sink by rotating. The drain is held on by a nut and sealed by a large rubber washer from below and plumber's putty from above. Remove the nut a washer and push up the drain. Apply ample plumber's putty to the new drain edge and push it into the sink hole. Put on the rubber washer, any steel washers provided, and the nut. Tighten the nut with channel locks. Putty should squeeze out all around the drain. Keep tightening until no more putty comes out. Then clean off the extra putty. Reattach the disposal or stopper and the trap. Check for leaks.

Toilets are fairly easy to replace. Shut off the supply valve or main supply to the home and disconnect the flex line from the bottom of the toilet tank. Flush the toilet to drain the tank. Remove the caps on either side of the flange and remove the attaching nuts. Remove the old toilet and carefully carry it out of the home, as there is still water in the internal trap. Clean up the flange and install a new wax ring of the correct size. Make sure the bolts are still in the smaller slot of the flange and upright (the flange bolts slip into a hole from above the flange and then slide into a slot to hold them down). Carefully place the new toilet down onto the bolts. Twist to align properly to the wall and room. Tighten the nuts gradually from one side to the other until the toilet base is firmly on the floor. The toilet should not rock, but do not overtighten the nuts, as this may pull the bolts through the plastic flange. Reattach the supply hose and open the valve. Adjust the stop level in the tank per manufacturer's instructions and check for leaks in both the supply line and the sewer flange on the floor. If there is another floor below the toilet, flush several times and check for leaks downstairs. If there are leaks, remove the toilet and check the wax ring. A misaligned flange may be corrected for by using an extra-large or double wax ring seal.

Toilets and faucets can also be repaired to some extent. A faucet that still looks good but leaks because the valves wore out can be repaired by replacing the valve cartridges. Similarly, toilet inlet valves that overflow from the tank into the bowl and flapper valves and cause the tank to refill frequently can be replaced with just a channel lock plier. Faucet knobs are usually held on by screws that are under the "H" and "C" buttons (pry those off). Just shut off the water supply and remove the hold-down nut. If there is no nut, perhaps you have a screw-in cartridge-you can tell from the new one you bought to install. Otherwise, the cartridge pulls straight up after the nut is off. Some models may use a steel ring to hold the cartridge in, which is supposed to be removed with a special tool; but I use two small screwdrivers. Make sure there is some lube on the new cartridge o-ring, carefully press the new valve into place, and replace the nut or lock ring. Restore supply pressure and check for leaks. Toilet inlet valves are held in by a nylon nut under the tank. Shut off the supply, remove the flex line from the tank, and remove the nut with a channel-lock plier. Lift the valve out and reverse the procedure to install the new valve. Make sure you restore the small bowl refill tube from the valve to the large overflow tube. Open the supply valve, check for leaks, and adjust the water level according to the manufacturer's instructions. Flapper valves are fairly, idiot-proof, except for adjusting the length of the pull chain so that a flip of the lever lifts the flapper vertically without the lever hitting the tank top. I usually have to adjust them once or twice to get it right.


Garbage disposal and dishwasher replacement.

Most dishwashers require their drains go thru a garbage disposal to ensure they do not clog your home drain with food residue. Most garbage disposals include a dishwasher drain inlet above the blades, but there is usually a plug in the new unit that must be punched out for the dishwasher to drain into it. The dishwasher drain is slipped over a nipple on the disposal and sealed with a clamp. Both hot and cold water must be supplied to the dishwasher using appropriate plumbing. Some dishwashers also have a vent line that can be installed on the sink. Follow the dishwasher manufacturer's instructions. The unit will also need 110 VAC supplied. Codes generally require GFCI protection for dishwasher electrical circuits and may require an independent breaker/circuit. Open the water supply valves and check for leaks. Run the dishwasher and check for leaks both under the dishwasher and under the sink/disposal.

The top side of a garbage disposal is installed much like any sink drain using plumber's putty. Before replacing a disposal, make sure it is bad. A disposal that just hums may be jammed. A large Allen wrench bolt under the unit is provided to break loose a jammed unit. The disposal itself is attached to the drain by lifting it up to the flange and rotating it to the right. There are three possible starting angles at which you can insert the disposal into the drain-use the one that puts the dishwasher nipple about 90 degrees to the left of where it needs to stop. I use a large Philips screwdriver in the disposal ring sleeves provided to rotate the disposal to the right, compressing the rubber seal firmly. 110 VAC under GFCI protection must be supplied through a switch near the sink. Check for leaks buy running water into the sink.


Lawn sprinklers.

Installing lawn sprinklers requires a lot of digging and plumbing. It also requires electrical work, if you want them to run on a timer. Local codes generally require backflow prevention devices. You can buy valves with built-in anti-siphon, but some areas require more than this. When I lived in Ohio, in in-ground backflow prevention valve was required and had to be tested annually. I got around this by designing a temporary installation using the outdoor faucets. Check your local codes before starting a sprinkler project. One positive thing about the Ohio situation is that they allowed a second meter for outside water use for which they didn't include the normal corresponding sewage fee.

A sprinkler system requires a significant design effort to work properly. Only so many sprinklers of a given flow rate will perform well in a circuit, depending mainly on the rated flow of each sprinkler and the water pressure in your area. The circuit size may also depend on the diameter of the valves and piping. I recommend at least 3/4" for a full circuit. If the circuit is only a few small sprinklers, you can get by with 1/2". I am assuming you will tie into the main supply line in your house or yard. Tying into a smaller branch inside the home will reduce the pressure available, and should not be done if you have a water conditioning system upstream of the tie-in (you wouldn't want to condition water that you use on the lawn). You can make as many circuits as you like, but controllers will typically run up to six circuits. I used two controllers in my Ohio home to run a total of ten circuits. Sprinkler placement is also critical. In general, you want adjacent sprinklers to be able to just reach each other. Pipe depth is also important. You don't want to hit any existing supply plumbing or electrical conduit while trenching, but you want to go deep enough to avoid piping damage from any lawn care activity, such as aerating (keeping the pipe along the perimeter of the yard is also helpful, if it doesn't drive up the total pipe length too much). There may also be local codes that apply to sprinkler pipe depth. I always use PVC of at least schedule 40 upstream of the valves. Lower schedule pipe is allowed downstream of the valves.

I have provided the primary considerations above, but you may need more help to complete the job. There are resources online for designing a sprinkler system. You can apply the plumbing and electrical techniques I have provided previously to complete the installation.

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