A Crosstie Retaining Wall

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Deadmen should be at least 1-1/2 times as long as the wall is high at the level where they're inserted. This allows them to penetrate beyond the soil that's actually bearing on the wall. Place them on eight-foot centers in every other course, starting with the second (unless there are only two) and staggering the courses so the deadmen don't end up on top of each other. Deadmen should be placed in alternating levels up to, but not including, the top.

A perpendicular member adds the weight of soil bearing down on it to that of the wall to aid in resisting overturning. Above three feet, however, sliding forces must also be considered. In such cases, a T should be added to the end of each deadman to prevent it from simply sliding through the soil. We pound a piece of 5/8" reinforcing rod through a hole in the end of the deadman and down into undisturbed soil (the length varies, depending on the excavation and the wall height), but a notched-in section of pressure-treated 4 X 4 would also work.

LAYING OUT THE WALL

If the ground you'll be building the wall on is perfectly level, and if the exact height isn't crucial, you'll be able to guesstimate the number of courses needed using a tape measure. Otherwise, a builder's level is the appropriate tool. Borrow or rent one, assemble it and level the base, and find a friend to handle the rod for you. Have him or her place the rod in what looks like a low point. Then look through the telescope and note the position of the crosshairs on the rod. If, at other locations, the number you see is higher, you've found a lower spot. This will be where the first course goes. You might be tempted to fill in the low spots to avoid having to lay in extra courses, but this would seriously compromise the strength of the wall; it's much better to start on undisturbed soil.

From the base, proceed upward in 6" increments on the rod, noting where the ends of the wall will be at each height until you reach the top. Using this technique, you can determine just how many ties you'll need. Add in the extras for deadmen and another 10% for waste, and you're ready to place an order that won't leave you either short or stuck with a big pile of extra ties. If you order 30 or more, the supplier will probably throw in delivery; if not, remember that crossties weigh about 100 pounds apiece.

When the ties arrive, sort through them and set aside any that are deteriorated or warped. You'll use these for deadmen and short sections. A warped timber, in particular, will play havoc with your level if used in the wall itself. Cut short or used as a deadman, however, it will work just fine.

LAYING UP A WALL

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