Frequently Asked Questions about Asphalt Roofing

If your roof has been properly installed, ventilated and periodically inspected it should last around 20 plus years, give or take.  If you see curled or cupped shingles, cracked shingles, exposed nails, worn off granules, holes, missing shingles, leaks in your roof, or storm damage it is time to plan for a new roof.

Although code does allow for an overlay of one layer of existing asphalt roof shingles, in many cases, we do not recommend it.  With a tear off of old materials, we can look for any structural damage that may have occurred due to storm damage, or age or both. If there are any defects in the roof deck like rotting, this would be revealed during tear off.  Also, starting with a clean deck, with fresh underlayments, results in a smoother finished roof system.

That being said, there is a stone coated steel shingle that does work well with an overlay because of the design of the panel. (Click here for more info)

The slope of the roof is measured by the vertical rise of the roof to the horizontal run.  It is expressed as a fraction. For example, a 6:12 roof slope means the roof rises 6 inches for every 12 inches of horizontal roof span. 

Same as slope. The terms slope and pitch are interchangeable.

A low-slope roof is not a good candidate for asphalt shingles.   An asphalt roof on a low-slope will allow for a greater potential for ice dams as water can be easily trapped

Also know as “roof felting,” it protects the roof deck from moisture prior to the shingle installation.  It does provide a minimal degree of protection should water get under shingles.

This is a special, waterproof, rubberized membrane underlayment that is required by Minnesota code. It is placed at the eaves of your roof.  It is different from a roof felting underlayment in that when installed correctly, it creates a waterproof barrier that helps protect against ice and standing water.

A ridge vent is a vent that is installed at the peak of a sloped roof.  Its purpose is to help keep the air inside your attic as close to the outside temperature as possible.  It does that by allowing warm, moist air in your attic to escape. The right combination of ridge vent and continuous flow soffit vents provides proper ventilation.

It is important to have a properly ventilated roof to remove the condensation and excess moisture in the attic.  Too much moisture inside the attic may leak inside a home even if the roof shingles and decking are sound. Also, ventilation extends the life of roofs, reduces energy costs, and prevents temperature differences inside one’s home.

There are mildew cleaners at home improvement stores that can be applied with a pressure washer.  Follow the manufacturers’ directions. Use caution when using a pressure washer so as not to have it on so high that you damage or blow shingles of the roof.