Nothing can be more frustrating to a property manager than a good old fashioned hard to find leak. Leaks come in all shapes and sizes, often at a trickle and often at a blast. However, at times leaks drive us crazy because of their occasional difficulty in diagnosing the precise source. When a leak like this occurs, a correct fix remains elusive!
When attempting to diagnose the source of a leak, you should first recognize that like so much else in life, its an exercise in problem solving.
First think about what kind of leak it is and identify what you definitely know. Is the leak continual or is it sporadic? If it's continual, there must be a source of water that continues. What has the weather been like? If its raining out, its likely to be entering the building envelope, but if the weather has been good, you've most likely got a pipe leak or a grouting/caulking issue.
Don't forget that even if the rains have stopped, you may be looking at a puddle on the roof for a prolonged period of time. If the water is indeed emanating from a puddle on the roof, remember that it may be entering in a crack around the seam of the drain and running down the outside of the pipe. And of course it is possible that the drain pipe itself is cracked. Try placing a hose of water in the pipe itself and see if there is a leak. If not, it's likely not the pipe itself but water getting in through the roof around the pipe.
If it's near a building façade remember that the water may be coming in through the masonry directly (look for damage where there's no damage above it), or running down from a parapet leak above (damage would be evidenced from the top down). If it's coming from the parapet, check the top along the coping stones to see if the seams have opened, and also check the flashing at the base to see if there are any cracks or openings. Look for moss on the stones themselves which might suggest the existence of substantial moisture.
Don't' forget that rains, like everything come in all shapes and sizes. An occasional rain may not generate the leak you've seen, but then here comes a wind driven rain and presto, she returns! In cases like this its more often than not cracks in the masonry.
If the leaks are more of an interior nature to the building, it's more likely to be a plumbing issue. Off and on leaks tend to be associated more with toilets and shower body's then a consistent leak which could be a break in a pipe in the wall. If it's an inconsistent leak, start with toilets and tubs. To diagnose toilets, try flushing and see if that causes the leak to appear. If so it's your waste pipe. If not, try throwing water along the floor around the toilet, to see if its perhaps a crack in the tile floor.
Similarly with showers, try plugging the drain and first run the shower and bathtub. If no leak shows up, try unplugging the drain and see if it's coming from the waste pipe as the water drains. When all else fails with the tub, try adding a small amount of food coloring so you are able to trace the colored water if it's indeed coming from a draining tub. Like with toilets, don't forget that it might be water finding its way down around the outside of the tub where it meets the floor, or even around an old standing waste pipe.
Don't forget if you are unsuccessful that it might be water getting through the tile wall. Try aiming the shower head at the wall to see if it's leaking through grouting or caulking cracks. In one situation, I was finally able to realize the leak would only show itself when a person stood in the shower and had the water bounce off at a certain angle against the wall. Don't ask how I figured it out!
Like so much else in property management, solving leak issues and finding their origins does not take a degree in astrophysics. A creative problem solving approach, coupled with patience and a lot of trial and error is all it takes to find your problem!

When all else fails, call a specialist...companies exist who do nothing but diagnose leaks using special sonar and ultrasound equipment! Try googling "Leak detection companies" and I'm sure you'll find one!

Matthew Engel, CPM, is vice president of Langsam Property Services Corp., New York, N.Y. Tags: