
Lots of experiments have been performed
(by others) when it comes to skylighting and if you have
one that is giving you grief we can fix it - right the
first time - guaranteed. For replacement price
information only, please scroll to the last paragraph on
this page. If you'd like to troubleshoot on your
own, read on as this page details the most common
problems we find.
More than half the time, when we get called out to fix a
leaking skylight on a pitched roof, we find trouble with
the flashings, which are interwoven with your roofing and
are responsible for diverting roof runoff around the
skylight. A flashing system has three main
components: a head flashing, a foot flashing, and side
flashings which, depending on the roofing type, may or
may not be segmented "step" flashings.
The head flashing is by far the most critical
component because it forms a gutter along the high side
of the skylight which has to handle everything that comes
running down the roof above it and it usually has to
accomplish that task while being loaded with varying
quantities of debris.
So, the first order of business is to clean out any
accumulations of debris that you find in the head
flashing. Second, check to see if the bend in the
head flashing which forms the bottom of the
"gutter" you just cleaned is corroded. If
it is, it should be replaced. Third, check to make
sure that the head flashing tails out at least three
inches beyond the sides of the skylight. If it
doesn't, all of the aforementioned runoff is probably
being dumped right into the most vulnerable spot on the
system at the corner where the head flashing and top side
flashing meet.
Side "step" flashings must be properly
positioned and in sufficient quantity to do their job and
the most comprehensive diagrams on how to accomplish that
task can usually be found on the installation
instructions for your type of roofing material (often
printed on the packaging itself). In sufficient
quantity means there should be a flashing card installed
with every course of roofing. Spanning two courses of
composition roofing with a flashing card designed for
cedar shakes is a serious mistake with potentially dire
consequences that is still common practice among roofers
today.
If your side flashings are continuous, they must have
some form of barrier, usually found beneath the roofing,
to keep water on the flashing as it runs from the top of
the skylight to the bottom. The foot flashing should
extend at least four inches down the pitch from the base
of the skylight curb and should tail out beneath the
bottom step flashing card at least two inches. Needless
to say, all of the flashings should extend upward from
the roof deck far enough to be covered by the skylight
counterflashing.
If you have a built up roof, the corners at the base
of the skylight curb are the most vulnerable and
difficult to keep intact as your roofing goes through
daily and seasonal thermal cycles.
If you find all of the above to be in order and are
still having problems, you may need a new skylight.
Lots of them have been manufactured (by others)
that do not have a positive seal between the glass and
the frame and rely on a gutter/weep system built into the
bottom of the frame to get rid of the water and dirt that
inevitably gets inside. The weep system is in many cases
nothing more than two small holes drilled in the bottom
of the frame which can easily become clogged after a
time, the result of which is a flooding frame during hard
rains. The other problem often created by this
situation is the thermal death of the skylight glazing by
virtue of the edge being submersed in puddling water, a
physical impossiblity with our skylighting systems.
If you are in our NC Washington service area, our
replacement skylights sell for $40 per square foot
installed on standard roof pitches (4/12 or less) and can
be manufactured in odd shapes or sizes for a nominal
upcharge. A 10% upcharge is required for each
numerical roof pitch increase over 4/12, up to 8/12
maximum on cedar roofing, and up to 10/12 on composition. Steel is absolutely out of the question...
If you are unsure of your roof pitch, please
contact us for a free quote. Cedar roofing requires
a dry weather window or a very recent cleaning to
accomplish the replacement task.


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