Trouble In The Roof Valley
The roof valley is where two sections of the roof come together. A roof valley acts like a
funnel channeling large volumes of water at a high velocity. After the installation of gutter
protection, water could overshoot the gutters at this point. And even without gutter
covers, in a down pour, the gutters may be overwhelmed with rain water and overflow. This is not a
good situation as water then flows to vulnerable areas of the home and causes significant damage.
The overflow problem has been an issue for many a gutter guard contractor. The most common fix
is to install a diverter on to the roof to channel the flow of water to either side of the valley. Diverters can
make the problem worse. Debris gets backed up behind the diverter, and breaks down into an organic muck. This
muck will eventually overflow the diverter and clog the gutters and gutter protectors.
The best solution at this point is to install a small wedge of mesh in the valley on top of the gutter
cap. The mesh will allow the large volume of fast moving rain water to go into the gutter. The force of
the water is strong enough to keep the mesh free of debris so that it can be blown off.
There are some new developments in gutter cover finishes with roof granules being applied to the surface
of the gutter guard. The roof granules slow down the flow of water. Roofs with low pitches of 7/12 or less
donít require mesh or a diverter with the roof granule finish.
The roof valleys also funnel debris into the gutters or on to the gutter protection. Excessive debris
in the roof valleys are the greatest source of clogs in gutters and gutter guards. The debris is not as
likely to be blown off in the roof valleys due to the two sides of the roof acting as a wind break. Debris
degrades into an organic muck. It eventually comes down the roof as a mud slide. This problem is made worse
with roof designs where several valleys drain into a small section of gutter.
There isnít a good solution for debris that accumulates in the valley. All gutter protections will have
issues from the debris degrading into an organic muck and then clogging the gutter cover. From time to time,
the roof valleys should be cleared of debris. This should be done every couple of years with most homes. The
frequency of cleaning the roof will be determined by the number and type of trees around the home. Another
factor is precipitation. Excessive rain will keep the debris moist and too heavy to be easily blown out of the
roof valleys. Excessive debris build-up on roofs is problematic in rain forest areas such as Washington
In the winter time, itís the accumulated snow that causes issues. Large amounts of snow and ice
accumulate in the valley. Eventually, just like in the mountains, a glacier of ice and snow starts moving
down hill and damages everything in its path. The glacier terminates at the gutters, where usually huge
icicles form. Sometimes the weight of the icicles tears off the gutters and gutter covers.
There is a good solution to this problem with a product called Heater Cap.
Heater Cap is mounted on the gutter protectors, in the gutters, down the down spouts, and 4 to 8 feet up and down
the roof valleys. If there arenít gutter covers, the Heater Cap can be installed in the gutters, roof valleys
and down spouts. Heating the valleys is important because, a large volume of ice will eventually come down at that
point and be much harder to melt. This area needs preventive care to avoid ice accumulating in the roof valley.
An experienced gutter cap contractor will tell you that roof valleys are the biggest source of service issues
with or without gutter covers. Yet there are permanent solutions in many cases. When choosing a gutter cover
contractor, ask how they will deal with your roof valley issues.