Natural Paths and Walkways

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In the old days, they knew that the secret of a really permanent walkway is a solidly compacted base that extends below frost. My mother's house was built in 1921 and has a loose-brick sidewalk and gravel-on-packed-clay driveway leading back to the old Model A-sized garage. Both are as solid as if they were granite ledge. I was visiting the grandparents one time back in the 50s when the water company dug through the yard to install a new supply line. Beneath both walk and driveway, a core of nearly rock-hard base went down deeper than they laid the water line—and the guys were standing waist-deep in the trench. And, that's nothing compared to Roman chariot ways—built where frost never happens but that have compacted rubble bases ten feet deep. The Roman roads are still in use today.

But during the housing boom that followed World War II, contractors' standards declined to the point that roads, paths, and drives were laid right on top of fill—soil that had been dug out for foundations or artery roads, then bulldozed back and maybe rolled once or twice.

The problem is, once disturbed, soil that's been settling for 10,000 years gains a good 1/3 or more in volume—all of it air. Unless properly recompacted, it will settle slowly for the next 10,000 years, and won't support a rigid surface in the interim.

So, when you dig down for your hardtopped path, practice "skimming." Remove sod and topsoil down at least six inches into subsoil, and eight or ten inches is better. When you get near your base depth, scrape shallow with a flat shovel or sharp hoe so's not to disturb soil that won't be removed. Make the bottom fiat and level. Cut sides of the trench sharp and square too, so you have undisturbed soil along the sides as well as at the bottom. This will help restrain sideways slippage of your surface materials.

Use a level to even off the bottom of the trench at a uniform depth. Then, add a bedding of road fill—not gravel or sharp sand or crushed rock as recommended till fairly recently. Road fill is a mix of fine- to medium-grade crushed local rock variously termed "Class 2" or "3/4-inch" or "21A" It's the stuff that goes under new first-class highways. Calculate the cubic yards you'll need to fill the trench and order two-thirds as much more. It doesn't cost a lot but comes by the dumptruck load. If you are persuasive, the scaleman may let you pick it up in small lots at the crusher in your own vehicle. Keep it dry until it is covered by sand and pavers.

Add fill two inches at a time, tamping each layer with a rented gas-powered compacting sled, the head of a wood splitter maul or sledge, a length of wood beam, or a rented fiat-faced hand tamper. Pound till the fill smashes down to less than two-thirds of its loose height and till the sound it makes goes dead. If you want to get fancy, go to a paving contractor and get some geotextile fabric—black plastic sheeting that will improve the lateral stability of the bed so the soil under your pavers won't slump sideways. Put it over the bottom two inches of tamped bedding and up the sides. It will make a cleaner and more rigid job if you rim both sides of the walk with plastic edging at this point. You can get it where they sell the geotex.

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