ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Sunday, May 12, 1996 TAG: 9605130150
SECTION: HOMES PAGE: D1 EDITION: METRO
COLUMN: Hints for Homewoners
SOURCE: STEVE ELDER
You've just turned the dishwasher on when you hear a blood-curdling scream from the shower! This is not a remake of "Psycho," but rather a bad case of Old- Pipe Syndrome. Chances are that you have old steel water pipes in your home, and your housemate has just let you know that there is a problem here.
First, have your water pressure checked. Most municipalities deliver water at 45 to 60 pounds of pressure, which is more than adequate. Normally this is not the problem; but it is wise to check it anyway, because it's the cheapest first step. In instances where there is low water pressure coming to the house, it is possible to have a pressure tank installed on your main water entry pipe, just as is done on well water systems.
It is more likely, however, that the problem lies in the water pipes themselves. Most homes over 50 years old have steel water supply pipes instead of copper. What happens with old steel pipes is that rust slowly builds up on the inside of the pipe as the years go by. As the rust builds up, the effective inside diameter of the pipe shrinks, restricting the flow of water through the pipe. Eventually the pipe capacity is so restricted that when you operate two or more plumbing fixtures at the same time, the flow rate is insufficient to serve them adequately. Note that the problem here is ``flow rate,'' not water pressure. The distinction between the two terms is that ``water pressure'' refers to the force behind the water, whereas ``flow rate'' refers to the amount of water. It is very possible to have a perfectly adequate water pressure to your home, but a flow rate that is inadequate because the pipes have become too small.
In the Roanoke area the problem is compounded by the fact that many older homes were built, not with the usual 3/4-inch mains, but with 1/2-inch mains. These pipes were small to begin with, and when they develop arterial sclerosis, it makes for a significant drop in flow rate.
Unfortunately there is no cheap and easy fix for the problem, and you will probably require the services of a professional plumber. However, it is possible to set up an incremental strategy in order to cushion the financial shock. Since most of the rusting occurs in the horizontal pipe runs, have the accessible horizontal piping in the basement and crawl space replaced first. In many cases this will buy you a few more years. When you do this, be sure to replace the old main water valve with a new full port valve. The older valves have a marked constriction in the gate mechanism, whereas the new full port valves have an internal diameter almost the same size as the pipe.
They have the added advantage of being easier to operate. All you need to do to shut the water off is turn a convenient straight handle 90 degrees. The old valves have a round handle, which is hard on the hands and besides is usually locked up because nobody has touched it for 10 years. (All water valves should be operated at least once a year to keep them limber.)
If replacing the horizontal runs has not boosted the flow rate to an acceptable level, you'll have to take the next step of replacing the vertical pipes (risers). This is more expensive, because some of your walls and ceilings may have to be opened in order to install the new pipe. This is particularly likely if you have a two-story home. In one-story homes the risers can sometimes be pulled and reinstalled from below, with very little damage to the walls. There is also some flexible copper water pipe on the market that makes retro-fitting in older homes much easier.
Water-pipe replacement will run between $4 and $7 per linear foot in open areas, and between $10 and $18 per linear foot in walls and ceilings. Houses and working conditions differ, so get several estimates from licensed professionals.
Finally, if you've replaced all the old interior water pipes, and the flow rate still isn't satisfactory, then the problem has to be in the main line serving the house. Correcting this situation usually means digging a trench from your foundation wall to the street in order to put in a new 3/4-inch copper main. Depending on the length of the run, this can cost from $600 to several thousand dollars. Again, get several estimates.
LENGTH: Medium: 73 linesby CNB