Chasing leaks

The next step would be to determine if any of the exposed plumbing is leaking. This is done by checking around fixtures for any visual, or touchable, signs of moisture or leaking. Failing that, non-destructive testing is the next option. Solving moisture problems without having to break through walls or cut into roofs is a science but since water is a trickster, success in tracking down the source of leaks that cause moisture is not guaranteed.

The first step to take in any moisture inspection is to get a clear indication of where the moisture is through infrared imaging. The most common assumption is that where there is moisture, a leak must be nearby. This is not necessarily so. Water, as we know, follows the path of least resistance, so where it originates and where it ends up is anyone’s guess.

To put it plainly, the job of a thermographer is to chase down the moisture and deduce the area in which the source “may” be located. Thermal imaging allows us to locate areas where moisture is present through the cooling effect that the moisture has on the temperature of its environment.

Figure 1 shows the effects of moisture penetrating and saturating the ceiling of a condo unit. The client called us in hopes of being able to determine where the leak was originating. The possibility of the leak coming from the roof was ruled out. Knowing that water will travel downward, the investigation led the technician to the units above this one to chase down the source of the leak.

The unit above it, Penthouse #2, also showed signs of moisture penetration on the floor (see Figure 2). The unit above it, Penthouse #3, showed no signs of moisture. This indicated that the source of the leak was somewhere in close proximity to the ceiling of Penthouse #1 and the floor of Penthouse #2.

The technician’s first thought was that perhaps water was infiltrating through a dryer vent (to the outside) causing condensation and the resulting moisture between the two units. The leaks were typically prominent when there had been a good rain.

The fact that the leaks were happening with rain, led the technician to investigate the outside sites that water could be infiltrating. This is where he found the culprit, which was a clogged drain pipe from the balcony of Penthouse #3.

The most common sources of leaks are generally building envelope related leaks through the fenestration or cracks in the curtain wall. These are usually the easiest to find and mitigate as it is possible, even when moisture is not present, to detect the paths where outdoor air is infiltrating the building envelope. When chasing leaks in the interior of a building, faulty caulking around showers, bathtubs, and toilets is a common source of the problem and the first place to look.

A client had been seeing moisture in their condo unit and the unit below was clear of moisture. Investigation around the shower detected that moisture was collecting in the drywall around the shower stall.

In a similar situation for a single family home, the homeowner visibly noticed signs of moisture on the drywall and floor (baseboard) of the master bathroom. When the technician first inspected the drywall with thermal imaging there were no thermal signs of moisture in the drywall, even when they pulled up the baseboard (see Figure 3).

An investigation of the home’s infloor heating system ruled it out as a possible issue. However, after running the shower briefly it was easy to see using the camera where the moisture was escaping through faulty caulking around the shower into the drywall and floor.

Contractors performing investigations using infrared imaging should be properly certified and use a camera with a minimum of 76600 infrared pixels. The images shown here were taken with a thermal imaging camera at 307000 infrared pixels.

Leaks are not always visible to the naked eye. Further investigation with thermal imaging, and of course, the expert eye of a trained thermographer can save a homeowner a lot of strife. Tracing the damage back to possible sources quickly will ensure the water damage does not cause more serious problems such as mould.