Time to replace the roof

Telltale signs of age with popular roofing materials
By: Paul Bianchina: Inman News
The phrase, "having a roof over your head," takes on a whole new meaning and sense of importance when that roof begins to age and wear out. Replacing your home's roofing is a big investment, so how do you know when it's time? Other than the obvious signs of missing singles and water leaks, here are some things to look for with two of the most common and popular roofing materials.

COMPOSITION SHINGLES

Composition shingles get their name from the fact that they are made up of a composite of layers of different materials. They are typically a combination of asphalt-coated papers and strands of fiberglass mixed with other materials, which make them durable and waterproof, topped by a coating of colored mineral or ceramic granules that give the shingles both color and a tough, wear-resistant outer layer.

Composition shingles, depending on their thickness and the number of layers they are made up of, as well as the severity of local weather conditions, can be expected to have an effective lifespan of approximately 18 to 30 years. Over time, the elements will take their toll, and one of the more noticeable things to be looking for is the wearing away and sloughing off of the granules from the surface of the shingles. This may become visible in random shingles on different parts of the roof, which is typically due to subtle differences in how they are manufactured, or in whole sections of the roof, which is more indicative of weather exposure.

Another warning sign of aging for composition shingles is a failure of one or more of the layers. You may begin to see some of the fiberglass granules or mat layer appear through the black of the asphalt, or you may become aware of blistering, cracking, or delamination of the layers. These signs are a little harder to spot from the ground and should be part of an annual examination of the roofing from above.

WOOD SHAKES AND SHINGLES

Wooden roofing materials, which may be relatively thin shingles or thicker shakes, have an effective life span of about 15 to 20 years. As with any natural wood product that is exposed to continual cycles of wet and dry, wood shakes and shingles will eventually begin to warp and curl.

Warping occurs along the length of the shingle (or shake), and becomes evident when the ends of the shingle begin to lift up off the courses of shingles below them. Curling occurs across the width of the shingle, and when viewed from the end you'll see the edges lifting up in a cupped shape.

Both of these conditions leave the roof vulnerable to water intrusion. In colder climates, that water can freeze, which makes the movement of the shingles more rapid and pronounced. During winter rain and snow cycles as the wood becomes saturated, the curling and warping becomes a little less noticeable, but during each summer's drying cycle it will become increasingly more pronounced.

Because the wood is no longer flat, the roofing is also very vulnerable to damage from impact. Even very small tree branches that come loose during windstorms can crack the shingles, and walking on them during the heat of a summer's day can do a tremendous amount of damage.

The wetting and drying cycles will also cause an increasing amount of movement between the fibers of the wood, which in turn will begin to loosen their grip on the nails or staples that hold the roofing in place. This will begin to show itself as shingles or shakes that start sliding down or moving out of alignment with the ones surrounding them, and you will also begin to see fasteners that have worked out completely and are lying on the roof.

TIME FOR AN ESTIMATE

As these different warning signs begin to appear, it's time to have an experienced, licensed roofing contractor take a look. They can give you an assessment of the condition of the roofing and an estimate of how much more life you roof has, as well as an estimate of the replacement cost and what options you might have for new materials. Roofing contractors and life span opinions are not always created equal, so for an investment of this size and importance, getting two bids is usually a very good idea.