Flat
roofs would seem to develop more problems than pitched roofs, but
some of the problems can be avoided with a little preventative maintenance.
This means a flat roof should be inspected for cracks, exposed nail
heads and flashing, and general damage at least twice annually-four
times if possible.
Flat
roofs are constructed of a series of asphalt roll roofing and/or
asphalt building paper criss-crossed and "hot mopped" with hot asphalt
liquid. A layer of gravel or crushed stone is embedded in the hot
asphalt to finish off the surface. Because of this construction,
flat roofs are usually installed by a professional roofer since
the equipment necessary would be too expensive for a homeowner to
buy-especially for a 1-time roofing project-or even for re-surfacing
as wear and tear dictates. However, there are some maintenance repairs
that you can make, and these repairs are detailed in this article.
CAUTION:
Climbing up onto any roof can be dangerous. Be extra careful and
follow these simple rules:
- Do
not lap the extension of a 2-piece ladder LESS than 3 rungs.
- Set
the ladder on even, firm footing.
- Extend
at least 3 rungs up over the eaves of the roof. You want to step
from the ladder onto the roof. Do not climb over the eaves and
guttering onto the roof The extension hooks must be hooked. Check.
-
Watch out for overhead power/phone lines.
- Climb
the ladder one rung at a time. On the ground, the ladder should
slope about one-fourth its length from the side of the house.
Example: if the ladder is 16 feet long, it should be pulled out
at the bottom 4 feet from the side of the house.
- Check
the rungs for safety by walking on the rungs with the ladder flat
on the ground.
- If
the ladder even appears damaged, do not climb it under any circumstances.
WHAT
TO INSPECT:
Since most flat roofs don't have a crawl space under them, you can't
go into the crawl space on a sunny day and look for pinholes of
light that detect holes. Therefore, on a flat roof you have to guess
where the leak or damage might be. Water is very tricky: the leak
could be 10 feet away from the damage causing the leak. That's why
very careful inspection is necessary.
Trouble
spots include these:
- Flashing
and roofing pulled away from chimneys, vents or tacks, and other
roof projections such as skylights.
- Exposed
roofing nail heads.
- Around
roof drains where water goes into gutters, or downspouts or other
drainage systems.
- Exposed
roofing-that devoid of gravel/stone.
- Roofing
seams or laps.
- At
junctures with other roofs.
- At
any valleys.
Pay
special attention around small discolored spots on roof gravel or
stones. Water often puddles in these spots (and discolors the stones)
and causes leaks. Also look for blisters in the roofing. In these
spots, the roofing has pulled away from the roof decking below.
This is a normal condition caused by moisture between the decking
and the roof membrane (building paper and/or roll roofing).
The
very best time to make a flat roof inspection and repairs is on
a fairly cool day when there is no moisture on the roof and no rain
in the forecast for a day or so. If it has been raining, let the
roof dry (it gets dry in a hurry under a hot sun). Make the inspection
and then determine the tools and materials you'll need and carry
them to the roof at one time. This way, you avoid lots of ladder
climbing and walking across the roof surface. We suggest that you
wear thick rubber-soled shoes, for safety, even though the roof
isn't pitched.
