Just like many problems in life, there is more than one way to fix a broken sprinkler pipe. The appropriate method depends on the damaged section's location. For instance, a clean break before the valve usually requires a hard pipe repair, while easier repair methods work fine when the damaged area occurs after the valve.
This guide will break down five different methods to repair a buried sprinkler pipe.
Finding the leak sometimes becomes the most difficult part of this project. Obviously some leaks are easier to find than others, such as a geyser that rips through the soil. In less obvious cases a homeowner may only notice a pressure loss at the end of a zone. In this situation, turn on the leaking zone. Stand back and compare the spray height of each sprinkler head. If you see a loss in water pressure between two sprinkler heads, suspect a leak between these two heads. Go to the suspected area and look for overly saturated soil.
Remove the soil covering the broken sprinkler pipe with a shovel. When the tool's blade touches something hard, stop digging with the shovel and expose about a two foot long section of the pipe with either a hand or small trowel. Clear a 4- to 6-inch deep trench under the sprinkler line. This gives the water inside the pipe a place to drain.
Identify the pipe size before shopping for repair fittings. The person at the hardware store does not know what size pipe you have. Manufacturers print the pipe size on the side of the pipe. Unfortunately this is often hard to read when on older buried pipe. In this case, wrap a piece of string around the pipe and make a mark where the end meets. Go the hardware store and use the string to identify the pipe size. If you feel the need to gamble on pipe size, choose 3/4 inch.
Irrigation repair technicians use a saddle repair kit to fix a cracked section of straight pipe, such as when someone punctures a sprinkler pipe with a shovel. The pieces in these kits hug pipe, not fittings; leaking fittings require a hard pipe repair. Some kits use a PVC saddle and cement, while others use a rubber gasket and metal clamps.
PVC Saddle style
Many homeowners love the trees in their yard. Unfortunately as the roots grow they push up on any irrigation pipes running above them. Eventually the tension causes the pipe to crack and leak. The root's upward force creates uneven pipes that sit at odd angles to each other, making a hard pipe repair difficult. To make matters worse, removing the offending root can damage or kill the tree. A flexible coupling solves this issue without cutting the roots.
Irrigation repair technicians looking for a no-glue fitting often choose to use a PVC compression coupling, sometimes called a dresser coupling. A PVC compression fitting uses rubber gaskets as a mechanical sealant. When the technician tightens the fitting's nuts the nuts force the rubber rings into the void between the pipe's outer surface and the fitting. If the fitting leaks, the technician simple tightens the nut another half turn. Unfortunately a PVC dresser fitting should not be used on a constant pressure pipe, such as the pipe feeding the valve. In that case, pick a different repair method.
An expanding coupling, sometimes called a telescopic coupling, works well when replacing a leaking fitting located in a tight space, such as inside a valve box. The stationary end of this fitting attaches directly to a section of pipe and the fitting's movable shaft slides into another pipe fitting. Occasionally a repair technician completes a hard-pipe repair with an expandable coupling; however, this situation rarely happens due to the fitting's high cost.
Occasionally it makes sense to build a hard pipe bridge using PVC pipe and fittings, such as when a sprinkler line passes over multiple growing tree roots or when the leak is located in an area too small for other methods. The exact type and amount of fittings needed depends on the situation, however, most pipe bridges use four 90-degree fittings and a section of pipe.
© 2019 Bert Holopaw