The part about it always flowing downhill is the key to finding leaks in sloping roofs,
but while it is still true when it comes to flat roofs, locating the downhill part can be tricky,
if not impossible. That is because with flat roofs, water tends to penetrate the roofing material
and then flows downhill underneath it until the water finds a way into the structure. In other
words, the leak in and the leak out can be quite far apart.
Here is my experience with locating leaks in flat roofs:
First, just because you know where the water is coming in, say your bedroom ceiling, does not
mean this is a clue as to where the roof leak is. Just accept the fact that there is a leak,
and then move along to the roof itself.
Second, just because it is easy to walk around on a flat roof does not mean finding the source
of the leak is going to be easy.
Third, look for the leak when the roof is dry. You will see plenty of evidence where the low spots
are; think rings of watermarks or an accumulation of sediment. Take a hose or other water supply
up to the roof. Be sure to pack a cold drink (or hot), something to snack on, and your patience; especially
your patience. I would also recommend a pad of paper, pens and a digital camera to record
the problem and to keep track of the areas you test. (Photos will simplify getting bids to repair the roof, once you have found
the leak.)
Starting with the areas where roofing material meets up the masonry, chimneys, pipes, vents,
skylights, or other things that butt up against or poke through the roof,
look to see if there are any gaps or places where the flashing or roofing material has pulled away.
Also, if has been a while, say never, since you have been on your roof, do not be surprised to find
it lush with vegetation, especially if the roof is a double layer of material. Moisture that has
accumulated between the layers heats up in the noon day summer sun and tends to bubble the top
material. At night this contracts. At some point, after enough heating and expansion cycles,
these bubbles develop minute cracks and crevices. Nature will not be denied; lo and behold, plant
material has begun to blossom. These oases may be the source of the leaks or may just be another
area that needs to be repaired.
Fourth, after you have gone over the entire roof and located the potential trouble spots,
it is time to see which ones are actually leaking. Taking the potential trouble spots one at a
time, give the area a good soaking, spraying it from several different directions. Then check
inside of that is the source. Repeat as necessary.
Keep In Mind:
1. There may be more than one source of the leak, even if it only shows up in one area on
the inside. Several leaks may be feeding into one low spot underneath the roofing material.
2. Any gaps you found in the flashing, etc should be repaired even if they are not the source of
the leak, because they will be.
In Part 2, I will discuss the various ways to repair flat roofs, which ones are DIY and which are best left to the pro's.
Roof ABC's - The Basics
Cleaning Out Gutters
Please email me at deb@fsbocomplete.com
with your thoughts, comments, questions, or just to say "Hi".
Deb
