Baltimore Chimney /
A fireplace can be a truly marvelous
thing. They are usually the centerpiece of any living room they
happen to be in. A fireplace provides ambiance, warmth, and mood,
all while lowering your heating costs. But, to have one you must
also have a big hole in your roof. This is where the potential for
trouble comes in. This article will discuss the basics of getting a
good, weather tight seal around your chimney.
When dealing with leaks, place
flashing high on the list of usual suspects. It is the most common
thing to go awry, and chimney leaks are no different. Flashing is
sheet metal that keeps the transition between the chimney and the
roof watertight. If water manages to get behind the flashing, it can
do extensive damage to the roof decking, framing, and even the
interior of your home. You will want this fixed immediately, in
order to avoid expensive repairs.
To properly install flashing will
require two layers. The first layer is called step flashing.
L-shaped sections of sheet metal are woven into the shingle courses
and lapped up the side of the chimney. The next layer of metal
(counter-flashing) should be imbedded in the mortar joints of the
chimney and folded down to cover the step flashing.
Even if installed by a skilled
professional the corners will need a bit of extra attention. As the
metal is cut and bent around the corners it leaves a very small gap
that should be sealed with a quality urethane caulk. Please note
that extra caulk is not a viable substitute for quality flashing
There are quite a few different
metals used as flashing. Aluminum and galvanized steel are two of
the most common types. Copper is available, and lasts a very long
time, but as you may have guessed it also happens to be very
expensive. Lead is also used, and its malleability makes it rather
easy to work with.
If a chimney happens to be located at
the bottom of a roof slope, it may be a good idea to build (or have
built) a cricket. A cricket is a small diversion roof built on the
high side of the chimney. This roof helps keep the flashing from
being slammed against by water rushing down the length of a roof
It is a very good policy to inspect
the seal around your chimney every year or two. Look for missing or
damaged flashing, as well as cracks in the masonry. Small cracks can
be caulked with a masonry specific caulk. Some builders even
recommend spraying the chimney with a silicone based sealant to keep
moisture from soaking into the brickwork.
I’d like to mention again the
importance of quality work. Do not attempt to fix a problem on your
own without the proper tools, and know-how to get the job done
right. The money saved by doing it yourself can be very small
compared to repair costs stemming from improperly installed