Sewer pipe bursting in West Des Moines: replacement without the trench

When the pipe is too far gone to line

Some sewer laterals in West Des Moines are past the point where a liner can be installed. Orangeburg from the 1950s and 1960s that has ovalized until the camera cannot pass. Clay tile crushed under a driveway where a trench settled and a delivery truck finished the job. Cast iron whose bottom has rusted away for a long stretch, leaving a half-pipe sitting in mud. A lateral that was undersized when it was built and now serves an added bathroom or a second unit. For each of these, the choice is between excavating the full run or bursting it, and bursting usually wins where the pipe passes under anything the owner does not want to replace.

How the bursting head does its work

A steel bursting head, shaped like a cone and slightly larger than the old pipe, is pulled through the West Des Moines lateral by a hydraulic rig or a winch cable anchored at the exit pit. As it advances it splits the clay, cast iron or Orangeburg and pushes the fragments into the surrounding soil. Attached behind the head is a length of fused high-density polyethylene pipe, which follows into the void the head opens. When the head reaches the exit pit, the new pipe runs the full length of the old alignment in one jointless piece. The old pipe is not removed; it stays in the ground as broken fragments around the new one.

Two pits and what sits between them

Bursting needs an entry pit and an exit pit. On a West Des Moines house lot the entry pit is usually just outside the foundation where the lateral leaves the building, and the exit pit is at the property line, at a cleanout, or at the connection to the public main under the street. Everything between the two pits stays undisturbed: the lawn, the tree, the garage slab, the sidewalk. The length that can be burst in one pull depends on the rig, the soil and the pipe, but a typical residential lateral is done in a single run.

Before a pit is opened, utilities are located and marked. Gas, water and electric services often run near the sewer, and the outward displacement of soil during a burst can disturb a service that is within a foot or so of the lateral. Where the camera footage or the locates show a tight crossing, the installer exposes it by hand or chooses a spot excavation for that section.

Upsizing, fusion and the new connection

Among trenchless methods, only bursting can make the pipe bigger. A four-inch lateral can be replaced with six-inch HDPE by using a larger head, which matters for West Des Moines properties that have added fixtures or units over the years. The HDPE is joined by butt fusion on site: pipe ends are heated and pressed together into a joint as strong as the pipe. At the exit pit the new pipe is connected to the main or to the remaining sound pipe with a transition fitting, and at the entry pit to the building drain. A cleanout is normally installed at the house end while the pit is open.

• Utility locates and permit in hand before any digging
• Entry pit at the building, exit pit at the connection or property line
• Fused HDPE staged in one continuous length
• Burst and pull, then inspection of the new connections before backfill

Permits, streets and frozen ground

A bursting job in West Des Moines needs a plumbing permit, and because the exit pit is frequently in the public right-of-way at the main, a street opening or right-of-way permit from the city or from Polk County and a traffic control plan are common. Deep frost in northern cities makes winter pits slower to dig but does not stop the work. Long laterals that run far under the street are where bursting saves the most, since a trench there would mean lane closures and pavement restoration for the full length.

Finding an installer and getting the footage

Not every lining crew bursts, and the equipment and training differ. Installers who have been verified by the network are listed at the verified installer roster, with the background on liner and replacement methods at the cured-in-place pipe reference; a search for crews serving West Des Moines is available at an installer search near West Des Moines. The decision still starts with the camera: if the footage shows a pipe that can be lined, bursting is more than you need. Call (877) 880-8125 to have the lateral inspected. Estimates are free. Call now.

Estimates are free. Call now: (877) 880-8125.

Other trenchless services in West Des Moines

Questions we hear about pipe bursting