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Re: locating pipes under concrete floor

From: info@builderswebsource.com
Category: Plumbing
Remote Name: 63.198.181.43
Date: 19 Aug 2001
Time: 10:27 PM

Comments

According to the Foundation for Water Research:

There is no single device which will be applicable in all [plastic] pipe locating and leak location situations. Each device looked at requires a degree of experience and skill to enable it to be used to its full effectiveness.

The following pipe location techniques have proved successful and are exploited by commercially available instruments:

• Insertion sondes
• Hydraulically generated acoustic pulses
• Electrically generated acoustic pulses
• Electro-magnetic induction

A number of other techniques offer a potential solution but there is, as yet, either no evidence of their effectiveness or no commercial exploitation.

Insertion sondes transmit a radio wave frequency and can be attached to a flexible snake. A specialized receiver locates the transmission, allowing the operator to trace the location of the buried pipe. These devices are fairly expensive (about $1,000 on up). Metrotech (http://www.metrotech.com) is one such reputable supplier of flexible transmission sondes for locating buried pipe.

In extreme cases, X-rays can also be used, but this is more common in commercial situations. We recommend that you hire a local company that specializes in locating buried pipe. They may be able to insert a tracer wire or sonde into the line and "ring it out" to detect its exact location under your slab.

As to the best way to clean concrete off the plastic, we recommend a diluted solution of muriatic acid (hydrochloric acid) or, as a second choice, phosphoric acid. Muriatic acid is used to etch concrete and is highly toxic due to the release of chlorine gas, so be sure to wear goggles and a respirator along with protective clothing and rubber gloves. Make sure there is plenty of ventilation in the area, as well as water in the event of an emergency. Either of these acids will help to dissolve the residual concrete residue without affecting the plastic pipe. Phosphoric acid tends to be milder and is often used to remove grout smears from ceramic tile. Either of these products should be available at any home improvement or building supply store near you. Always test a small area first before proceeding.

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