Smoke Testing your Drains

How Smoke Testing can Speed up Plumbing Repair

What is Smoke Testing?
Smoke testing is an incredibly common method used in plumbing repair. The method involves pumping smoke through the plumbing system and looking for plumes of smoke exiting via cracks or other defects. The reason smoke testing is so handy is because defects are often found in places that are impossible to inspect without pulling up your lawn, and smoke testing can find these with a simple test.

Smoke testing will be done on a single line at a time looking for defects and after they are marked the next line is checked. This can be done without affecting the household and is non-invasive. Many times, the test is done in buildings or blocks of houses that are experiencing common issues.

How is it done?
Smoke testing can be used in many different ways, but in this article, we will be focusing on sanitary sewers. Sanitary sewers are complex and are not easy to diagnose. So the job is simplified by testing one line in the system at time, often the city will check a whole block in a day, but testing your drains won’t take as long. The other lines are blocked using water backflow or sandbags, then a fan is set up at each end of the line. These fans create a positive pressure in the pipes, just above atmospheric pressure. This forces the smoke from the smoke bombs or liquid smoke into the system.

The smoke is non-toxic and will not be dangerous to inhale, so you need not be concerned with children or pets. The smoke is simply water vapor and some highly visible particles, both will dissipate after a few minutes leaving no residue behind.

The testers will look for smoke plumes which have escaped the line. Each plume will be marked for further inspection as they are signals for defects in the system. You needn’t worry about smoke getting in your house as most drains have wet traps which prevent the smoke escaping and if they don’t then they are faulty and need to be inspected.

Why it is important?
Smoke testing may seem like quite a novel method for finding leaks, but it actually has a lifesaving benefit. Most of the water exiting a house is not dangerous or toxic, but any pipes containing sewage or connected to a sewage system can be problematic.

Sewage itself is toxic and if it leaks from the piping it can contaminate the ground water, which can be a nasty safety hazard. Smoke testing is able to detect these leaks, before they become a larger problem.

Though raw sewage may seem really bad, there are some deadly byproducts which can be released. These are the gasses methane and hydrogen sulfide. Methane is incredibly inflammable and a large leak could be a potential fire hazard. Whereas hydrogen sulfide is a poisonous gas and can be deadly. Due to the gaseous natures of these two, they don’t need a large leak to be a problem, but smoke can use the same leak just as well to detect it.

If you are looking to smoke test your home, contact Art Plumbing, Air Conditioning & Electric for a quote.