Slab leaks, sometimes customers ask, what is a slab leak.  The term slab leak is used primarily in the southern United States, by all plumbing contractors.  This terminology represents leakage on a potable water system such as copper water pipe, galvanize water pipe,  CPVC water pipe, polybutylene water pipe in which this product is no longer manufactured.  Copper water piping is the biggest culprit in slab leaks, because of its wide use all over the southern United States from Florida to California.

After 35 years in the plumbing business I am often asked, what about the copper pipe above the concrete floor why don't I have leaks there also.  Homes built in the 1960s and 70s on average can expect about 35 years of life from their copper pipes.  Homes built in the 80s and 90s can develop leaks early on and have a life expectancy in some cases between 5 to 12 years. Some copper water pipe will develop leaks that were installed in the 90s only two years after they were installed.  We at Hefner plumbing specialize in leak detection and re-piping.  In the past 30 years we have replaced well over 1,000,000 feet of defective copper In Florida.  We have found that soft copper and hard copper under the slab contributes to 98% of all leaks, we have also found that homes that were built in the mid-60s have better quality of copper and are less likely to have leaks although their time is coming. The term we use and have used for years, as we see it is called Industrial blight. We have found this to be the main culprit in this matter, along with oxygenation and soil dampness along with acid soils.

There's a lot of other contributing factors also, aggressive water pH, and acidity there has been a lot of rumors that electrolysis has something to do with it.  This is false.  We have tested the ground from the neutral side of the panel to the copper water line and this has no effect as far injecting electrolysis.  What we have found in the past, and in the present that if lightning strikes outside the building within 100 feet of the ground rod that lightning will travel through the ground wire that is bonded to the copper.  When this occurs, it weakens the integrity of the copper putting small divots in the  lining of the copper thus producing pinholes after two years on average, and failures began to multiple, also we feel that because of the cleaning steps that the manufacturer is supposed to go through, which is about 20 cleaning steps to purify the copper has been compromised in a way that foreign metallic’s form other properties have not been removed from the copper in the smelting process thus producing defects in the wall of the copper tubing.

With these defects in mind, the copper is aggravated by soil conditions and water conditions thus producing pinholes. Copper above the slab is not affected as badly although copper below the slab can be irritated by soil conditions.  This is why you don't see as many pinholes and copper above the slab.

My recommendation through performing this kind of work is to never break up the slap to repair a leak, unless the copper is hard copper type L which means that the joints and fittings are under the slab.  The majority of slab Leaks that we perform are of type L soft copper.

If there’s anything we can do at Hefner plumbing Co. to help you in any of these matters please don’t hesitate to call us.  352-620-2883 or 732-2626 or you can post your question online.