A very disagreeable feature of plumbing work in the home is the noise due to the operation of plumbing fixtures. In many residences the operation of the water closet in the bath room can be heard all over the building. Such noise, however, is unnecessary and can be avoided by intelligent design of the system and judicious selection of fixtures. Among the many closet combinatfons carried by the various manufacturers, each manufacturer has some one fixture which is less noisy than the rest, and for that reason is more suitable than the other fixtures for residence work. It is well to be acquainted with the various closets of the manufacturers so that when a noiseless one is wanted it can be specified by catalogue plate and number. But even when the closet is noiseless in operation, noiseless plumbing is not assured unless the supply and waste pipes are likewise proportioned to their several uses. If the supply pipes are too small there will be a disagreeable hissing sound when water is being drawn, not only at closet fixtures but at other points in the building. Further, if the pressure is high and properly designed faucets or suitable air chambers are not provided there will be a pounding noise when a faucet is closed, due to water hammer. These sources of trouble can be eliminated by using slow-closing faucets and large-size supply pipes to the various fixtures.
The noise of water from closet fixtures flowing through the soil pipe can be decreased in volume by using 3-inch soil pipes in the partitions, and the remaining noise can be almost entirely done away with by filling the space around the pipe and between the laths and plaster of the partition with some non-sound-conducting substance. Finally, the partitions around a bath room should be sound proofed, and, so far as possible, doors for bath rooms should be used through which but little sound will pass.