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I've done a bit of concrete flatwork-stairs, stair landings for decks, some slabs, and so forth-but now I have a client asking for a concrete walkway in front of his house and one section of it, say about 10 ft. long, slopes downhill. It's not super steep, but it did make me wonder if there's anything I need to know about ordering, pouring, and finishing concrete on a slope. I have visions of the wet concrete all slumping at the bottom and hardening in a giant lump.John Carroll, a mason in North Carolina, replies: The answer to your question can be found in the question itself. You're worried about the wet concrete slumping downhill along the slope, so the best way to avoid this is to order low-slump concrete, which is concrete with a low proportion of water. "Slump" is a term used to describe the consistency of the mix. In commercial work, a simple slump test of the concrete is often required in the field during the concrete pour. In this test, a 12-in.-tall steel cone is filled according to strict specifications. The steel is then slowly removed and the amount that the resulting cone of wet concrete settles, or slumps, is measured with a ruler. For example, if the concrete mixture settles 3 in., then it is said to have a 3-in. slump, or sometimes just a slump of 3. The stiffer (drier) the mixture, the lower the slump. The looser (wetter) the mixture, the higher the slump.