If you are burying PVC pipes outdoors for water supply, sprinklers, or other forms of irrigation, you may arrive at a situation where the pipes must pass under a solid concrete walkway. You don't want to break or cut the concrete, so what can you do?

The simplest and often easiest way to tunnel under a masonry path is to blast under it with water. To do this, you’ll need to make a special water-boring tool—a length of steel pipe connected to a hose.

Trench one access hole on each side of the walkway, perpendicular to the path, that will allow you to push the water-boring pipe under from one side to the other. (The chances are good that these holes will be a continuation of the trenches that you will use for running the irrigation pipe later.) Dig right next to the concrete to a depth about 6 inches below the slab, and below the gravel bed if there is one. The idea is to get down to soil that will be easier to burrow through.

Screw a garden hose onto one end of a 3/4-inch steel pipe that is long enough to span under the walk with a little length to spare. On the other end, screw a 3/4-inch to 1/2-inch reducer to ensure a more powerful blast. Turn on the water full-bore, and then use the pipe to erode a tunnel under the walkway. Wear rubber boots and be prepared for a muddy mess!