A Roofer’s Nightmare

Posted by in Roof, The Unusual | July 28, 2014

Roof leakage through an asphalt  shingle roof covering can be the result of many causes.  Sometimes the shingles were damaged by some event, other times its severe wear from aging, we have seen improper installation, or as we discuss here sometimes the poor roofer just had the cards stacked against him or her from the beginning.  How does one install a roof that doesn’t leak with the conditions seen here?

I call these “a roofer’s nightmare.”


Valley pocket

Valley runs into the corner of the wall.

Valley into a wall

A view down the valley.


Here a valley runs into the side of a wall.  With all these heating cables we see that this is a problem area in the winter.  There are way too many objects restricting the escape of wind blown debris, the flow of roof runoff, and the access for installation and/or maintenance in this area: half the the valley flashing terminates into a second floor wall, the rib of the valley flashing runs into the corner creating a small dam, the rake of the upper roof approaches the surface of the lower roof, even the gutter extends beyond the face of the rake to reduce open area, the nearby skylight comes close to the gutter, the wires restrict flow on the shingles and the valley, and the fasteners for the wires penetrate the shingles.


Valley into a roof surface

Valley runs into the adjacent roof slope.


Here, the point of discharge from two valleys meet behind a gutter.  The accumulation of tree debris demonstrates the problem.  One of the questions I ask is, “Why is the gutter there?”  Removing the gutter doesn’t solve the problem.  The next issue is the detailing of the flashing on the fascia behind the gutter.  Thank heavens for “Ice Guard.”



Valley into chimney

Valley discharge restricted by chimney and gutter deflector.


Here the valley ends near a chimney bringing roof runoff near the chimney flashing.  The configuration is such that tree debris is easily caught in the valley, especially at the discharge.  A gutter deflector was probably installed to reduce overflow from the valley; however, even if the deflector works, it is improbable that the short length of gutter can handle all that roof runoff.

These were just a few “roofer’s nightmares”  involving valleys.  Usually these conditions develop during a poorly thought out alteration or addition to an existing dwelling.  However, we have seen conditions similar to these in brand new construction.  With some of these conditions we wonder why they don’t cause more leakage than they do.