any tool to X-RAY the pipe leak behind the wall?

[smr]

As posted in other thread, I have a leak in my master bathroom in my third floor of a 3 story townhouse in chicago. The plubmer think there is a leak behind the wall around the toilt area. But the trouble pipe is not from the toilet, it is a return water pipe from the sink next to the toilet. I wonder if there is any tool can detect the leak behind the wall? Otherwise, if it is not the area we are looking for, I still need to spend time there and pay for the plumber.

Suggestions?

[LazyPup]

The term "return line" is a bit confusing as there are no return lines per se, with the exception of the return water line on a closed loop instant hot water system.

On the other hand, i get the feeling that what you mean by "return" line is perhaps a short waste arm from the sink drain to the main branch line in your bathroom.

If the leak is coming from a drain line, they do have a miniature closed circuit video camera system where a camera and light attached to the end of a probe is inserted into the drain pipe and the operator can inspect the pipe from the inside out by watching the results on a monitor screen. Once the point of the leak can be located in that manner, the probe cable is carefully measured as it is pulled out of the line to pinpoint the actual point of the leak.

The same technique can be used to inspect inside a wall. A small hole is made just large enough to insert the probe, then they visually inspect the lines. Unfortunately that type of equipment is very expensive and usually is only available through the larger Plumbing companies, and it can be quite expensive to have it checked in that manner.

If the leak is coming from a water supply line, you can have some limited success by using a "Digital Laser Thermometer" to measure the actual surface temperature of the external wall surface. The digital laser shoots a red dot against the surface in question, and it digitally reads the temperature at the specific point of the dot. they are commonly being used in such applications as measuring the temperature of motor bearings while a motor is running, but can be used in this application. Normally if there is a pinhole in a water line, the inside of the wall board will be soaked and it causes that section of the wall to be hotter or colder than usual, depending upon whether it is a hot or cold water line leaking.

The alternative would be to physically open the wall for inspection. Often this can be done in an out of the way place where the opening will not be seen and can be easily repaired such as behind a vanity cabinet or through ad adjacent closet wall.

[smr]

"On the other hand, i get the feeling that what you mean by "return" line is perhaps a short waste arm from the sink drain to the main branch line in your bathroom."

You are right on this guess. Sorry for my knowledge in plumbing terminology. Based on your info, i guess there is no equipment to detect my waste line problem. Am I correct? I think there is only small percent of plumber can offord this kind of expensive equipments.

Do you personally use this kind of detection before?

[LazyPup]

I was fortunate enough to have taken my apprenticeship under the Master Plumber who pioneered the idea of video inspection. While I do not currently have the equipment I do have a very close friend who does and i have rented his equipment on a couple occassions.

If you happen to have cast iron soil pipes, i can offer some informaton that may help you locate the problem.

A bathroom vanity bowl (bathroom sink) requires a 1 1/4" drain line. Although there is 1 1/4" cast iron pipe, it was not commonly used. Instead the put a reducing Wye on the branch line that has an 1 1/4 threaded side opening. The line was then run with 1 1/4" galvanized iron pipe.

While there are instances of the pipe wall corroding through, the most common point of corrosion occurs at the threaded joints where the zinc coating was cut away from the pipe during the threading process.

If you know where the drain, waste & vent stack rises up through the wall you can pretty much guess the layout. first imagine a line from the toilet to the stack, that should be the main horizontal branch for the bathroom. Next imagine a line straight down from where the sink drain connects to the wall. Depending upon the clearances, the line from the base of the sink riser to the horizontal branch will either run at right angles to the branch or at a 45deg angle from the base of the sink riser to the point where it joins the horizontal branch line. The 45deg angle will be in the direction of the downstream flow from the toilet.

i would begin by pulling the lavatory bowl cabinet away from the wall and opening the wall behind the cabinet. It would be easy to patch that hole and it wont require a finish as it is concealed behind the cabinet. If necessary, you could make another access hole in the floof under that cabinet, which again would be concealed by the cabinet.

Once you have a hole, get a small mirror ( i carry a ladies makeup mirror with a plastic frame about 2 x 5 inches). Hold the mirror inside the wall or floor cavity and shine a flashligth directly onto the mirror, it will reflect the light into the hole on your line of sight and you can see the results in the mirror.

Once you have located the leak in that manner, you will know exactly where you have to make an access hole to solve the problem.

If the problem is a corroded galvanized iron pipe, the best solution is to replace it with PVC.

If the galvanized pipe is leaking where it threads into a section of cast iron pipe, you can cut the galvanized off about 1/4" to 1/2" inch from the cast iron. You can then use a hammer and a punch to fold one wall of the remaining galvanized in toward the center of the pipe to loosen it. Once it is loosened enough to remove the stub of pipe, clean the threads of the cast iron with a wire bruch, apply pipe dope to the threads of a Male PVC thread adapter and screw the adapter into the cast iron, then you can run new PVC from that point back to the sink.

[smr]

"I would begin by pulling the lavatory bowl cabinet away from the wall and opening the wall behind the cabinet. It would be easy to patch that hole and it wont require a finish as it is concealed behind the cabinet. If necessary, you could make another access hole in the floof under that cabinet, which again would be concealed by the cabinet.

Once you have a hole, get a small mirror ( i carry a ladies makeup mirror with a plastic frame about 2 x 5 inches). Hold the mirror inside the wall or floor cavity and shine a flashligth directly onto the mirror, it will reflect the light into the hole on your line of sight and you can see the results in the mirror."

This 'lavatory bowl cabinet' you mean the cabinet holding the sink, right? How big is the hole normally it would have? If I do it bymyself, how long would be take?

Will the water inside the wall and ceiling be getten dried after the leak get stopped?

[LazyPup]

You should be able to disconnect the water supply lines to the sink at the angle stop valves on the wall, and disconnect the drain line at the trap or trap adapter, then pull the sink cabinet away from the wall.

I have attached an illustration for a simple method of making an access hole for inspection.

It would be impossible to offer a time estimate until the actual point of the leak is located.

Normally the water will dry inside the wall unless there is evidence that the sheetrock is saturated. In that case you may have to cut out the saturated sheetrock and replace it.

[hometutorer]

quote:Originally posted by smr

"I would begin by pulling the lavatory bowl cabinet away from the wall and opening the wall behind the cabinet. It would be easy to patch that hole and it wont require a finish as it is concealed behind the cabinet. If necessary, you could make another access hole in the floof under that cabinet, which again would be concealed by the cabinet.

Once you have a hole, get a small mirror ( i carry a ladies makeup mirror with a plastic frame about 2 x 5 inches). Hold the mirror inside the wall or floor cavity and shine a flashligth directly onto the mirror, it will reflect the light into the hole on your line of sight and you can see the results in the mirror."

This 'lavatory bowl cabinet' you mean the cabinet holding the sink, right? How big is the hole normally it would have? If I do it bymyself, how long would be take?

Will the water inside the wall and ceiling be getten dried after the leak get stopped?

o r oyetunji