Saturday, July 6, 2013

The Patio Project, Stage 4: Gravel

Having completed the excavation of the patio foundation on Wednesday morning, our next job was to fill it up with gravel to a depth of 4 inches. This phase of the Great Patio Project spread across three days, as we knocked off work early on Thursday to go celebrate the Glorious Fourth with friends. Loading in gravel might seem like a more straightforward job than the digging, which ended up turning into a sort of terraforming project, but once again, there were complications. Three complications in particular slowed down the work.

Complication #1: The slope of our yard isn't confined to the back yard. In fact, it slopes even more steeply from front to back, so that our back door is down one level from our front door. The only way to get from front yard to back is through the side yard, down a short, steep flight of concrete steps. This, of course, made it impossible for our truckload of gravel and stone dust to be dumped anywhere near the site of the future patio. It had to be dumped out in our driveway, and we had to cart it down by hand. We bought a small wheelbarrow (about 4 cubic feet in capacity) for about $35 at Home Depot, but that was only a partial solution, because a wheelbarrow obviously isn't designed to go down stairs. So Brian built a ramp out of scrap wood. However, his first test run with it revealed that it didn't offer enough traction for him to push a wheelbarrow down it and maintain control of it. So he modified the ramp by first pushing it to one side, so that he could keep one foot on the steps, and then applying some strips of traction tape that we bought for our basement stairs and ended up not using. This worked okay until dust started to build up on the ramp, making it slippery again. So it became my job, after Brian pushed the wheelbarrow down the ramp, to wipe it down with a damp rag and keep it as dust-free as possible. The traction strips started to peel off around the edges by the end of the second day of work, but it held up long enough for us to get all the gravel into the pit.

Complication #2: Remember how we saved the cost of an extra delivery fee by having the gravel and stone dust delivered in a single load? Well, the down side of this was that the gravel and stone dust ended up in a single pile, with the dust more or less on top—and the gravel was what we needed to use first. We could get at the gravel from one side of the pile, so we started there, but even there the gravel and stone dust had mixed to the point that we were invariably getting some of each in every scoop. To add to the muddle, we received our shipment of gravel on Monday morning in pouring rain, so the pile was thoroughly sodden. This meant that instead of just shoveling gravel, we were shoveling lumps of gravel in a matrix of wet stone dust. The term "stone dust," incidentally, is a bit misleading; its texture resembles nothing so much as clay cat litter. So the wheelbarrow, our shovels, and our work gloves all gradually built up a thick layer of cement-like grey mud, which made them heavier and heavier as we worked, so we had to stop periodically to rinse them. Also, the excess water made the material denser and harder to lift, so each shovelful contained a smaller volume than it would have if the gravel had been dry. All this slowed down the shoveling process, and it slowed still more on the second day, when we hit the point where what we could reach on top of the pile was mostly stone dust. After that point, we had to interrupt our shoveling to attempt to scoop the stone dust off the top of the big pile into separate, smaller piles to get at the gravel underneath. We pushed it around with the shovels and even sifted it through our fingers to remove the big lumps. We suspect there's still at least a bit of gravel buried under the stone dust we have left, but we got to a point where we had to just declare that we'd dug out all the gravel we reasonably could dig.

Complication #3: All those blocks of sod that we piled up around the edges of the patio pit in Stage 3 made a rather bumpy slope over which it was difficult to push the wheelbarrow. Brian fixed this initially by taking a piece of plywood that he'd been using as a worktable (propped up on a pair of sawhorses in the shop) and using it as a ramp to get the wheelbarrow over the turf pile and then dump it off the edge into the pit. However, there were two problems with this system. First, in order to get to the ramp, he had to push the wheelbarrow all the way around to the far edge of the pit, which was the one path that wouldn't take him over any of the turf piles. And second, he could only dump the gravel around the edges of the pit, and we needed to fill the whole area. So eventually he chose a spot on the near edge of the pit where he could manage to push the wheelbarrow up the rough slope, or steps, formed by the sod blocks, and repositioned the ramp so that it led down into the pit from there. He could then dump wheelbarrow-loads of gravel all throughout the pit, working his way in and back from the far edge.

By time we knocked off work on the second day, we had the pit completely filled with piles of gravel. Our challenge then was to turn these hills and valleys into a plain running roughly three inches below the line that we'd marked as ground level for the finished patio. We started out by walking on the piles to squish them down, and then we went to work with shovels and rakes and implements of destruction, pushing gravel from the mounds into the troughs. Then Brian got out a two-by-four he'd bought for the purpose and laid it across the surface with his level on top. This allowed him to check whether the overall surface of the gravel bed was sloping in the right direction, and also to identify any peaks and valleys that were still visible under the line of the two-by-four. So we repeatedly measured and tweaked, pushing a few lumps of gravel this way and that, until we had a roughly even surface. Then, for the final stage, we got out our tamper tool, purchased specifically for this project at Lowe's. Basically, it's just a flat, heavy metal plate attached to a long wooden handle, which you use to pound down the gravel bed so that it's as flat and firmly packed as possible.


The tamper is the one tool that we bought specifically and exclusively for the patio project; the wheelbarrow, though essential for this project, will also be a handy thing to have in the future. The tamper, by contrast, can only do one job, and it's a job we only expect to do once. But for this one job, you really can't do without it, so it was 30 bucks well spent. And as you can see above, by the middle of the day on Friday, we had a nice, level bed of gravel, on which we could begin piling our stone dust to make a cushion for the pavers. And since the stone dust is a lot easier to shovel than the gravel, we're likely to get through Stage 5 a lot faster than Stage 4.
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