The cost of a new asphalt composite roof in Portland, Oregon can be a major investment. Determining how big of an investment and its affect on your budget can vary depending on a number of factors. The first step in determining the cost of a new roof is measuring the the size of your home’s roof, not your home’s living area. Using Google Earth, it is possible to get a pretty close estimate using their measuring tools, or even better yet, you can take a tape measure and get it the old fashioned way. Once you have calculated the roof size, you will need to determine the pitch or steepness of your roof. By using a simple yard stick and level, figure out how many inches the roof rises over a one foot area. Most roofs will be between a 4/12 and a 9/12 pitch, which means for every foot of roof gain it rises 4″ or 9″. Note, roofs that are less than 4/12 pitch or greater than 9/12 pitch, taller than 2 stories may require additional materials or safety and are not included in our formula.
Next we need to know how many layers of old roofing will need to be removed. This can be determined by lifting the shingles along the gutter edge and counting the actual layers remembering that there is usually a starter shingle and then the actual roof shingle lays on top it. So two layers along the gutter edge generally means one layer of roofing and 3-4 layers equals 2 layers of roofing.
Armed with the above information let’s see if we can come up a roofing estimate that may be useful in creating a budget for this project. The formula is as follows:
Square Footage of the Roof x $5.5+ (Pitch 4/12 = .33) x Square Footage of the Roof + (Square Footage of the Roof x Number of Layers) = Approx. Cost of a New Roof.
Let try an example where the roof measures 2800 square feet, has a 6/12 pitch and 2 layers of roofing material. The formula work as follows:
2800 x 5.5 = 15,400 plus
.5 x 2800= 1400 plus
2800 x 2 = 5600
Equals $ 22,400
OK, there you have it. An approximation of what a new asphalt roof could cost you in Oregon. However, there are so many other factors that come into play like access, quality, decking, rot, venting, etc… that you need to have a professional estimator out once you are serious about getting a new roof installed on your home. But none the less, you now have an idea of cost and can start saving money for that day.