Roof Repair in the Portland Metro Area

Understanding Roof Repair

Many factors damage or limit a roof’s life across the Portland metro: extreme weather, constant moisture, tree debris, moss, poor workmanship, the wrong product for the situation, lack of maintenance, changes in building use, ventilation problems, questionable substrates, and improper remodeling practices. Every inspection has to consider all of them, because a leak is usually the end of a chain of events rather than a single failure.

Roof repair has been a steady need throughout the metro since the postwar building boom, when composition roofs went on in huge numbers under a maturing tree canopy in communities from Gresham to Hillsboro. The region also has the highest percentage of cedar roofs in the United States, along with tile, flat, and metal roofs, each of which fails differently. Repair requests spike every fall and winter as the October through May rains expose weak points across Washington and Clackamas counties, and again after storms like the February 2021 ice storm that dropped limbs from Happy Valley to Beaverton.

There are two types of repair, and understanding the difference matters. A temporary repair stops the problem now and leaves the long-term result for later. A permanent repair corrects the entire problem so the roof covering can reach its maximum life. Both have their place, and the right choice depends on the roof’s age, your budget, and your plans for the home.

Many people are led to believe that tree debris and moss do two things: lift shingles and “eat” a roof from the inside out. This is a partial truth, in that moss will root-in and grab onto the granules of the roof. When moss is removed, it takes the surface of the roofing with it. But moss and rooftop growth does not eat shingles.

In fact, the greatest problem we see with moss and tree debris across the Portland metro is the damming effect it has. The average roof shingle is 1 meter wide, leaving a joint between shingles every meter where the shingles are butted-up next to each other. When moss and/or tree debris line the bottom edge of the shingles and the vertical joint, we see water that would freely shed off the roof becomes dammed under the shingle. It then stays inside the roof assembly and tends to travel horizontally. What many homeowners in Beaverton, Tigard, Oregon City, and throughout the metro do not understand is that your nails are often only ½” under the lip of the shingle, and only 4 or 5″ from the joint between shingles. In other words, tree debris and moss re-route water in the roof, right to the nail holes in the shingles. That makes tree debris and moss the enemy of the roof.

Any abrasion on an asphalt roof lessens its life expectancy. In other words, cleaning can damage a roof. In fact, any cleaning likely damages a roof, but aggressive removal of moss and/or tree debris can radically harm the roof. So preventative maintenance is the best and most effective means of protecting your home and extending the life of your roof. There are conservative methods and approaches designed to protect and manage your roof as an asset throughout the Portland metro area.

The Northwest environment has the highest percentage of cedar roofs in the United States, and that is reflected in neighborhoods throughout the Portland metro — from Lake Oswego and West Linn to Tualatin Valley communities and beyond. Cedar is beautiful, and it adds charm and value to a house. Cedar can last many years. However, many of the products that are touted to extend the life of cedar and beautify an aging cedar roof can damage the roof. This happens through uneven application of products such as oils, or application of more caustic additives that can dry out fittings and corrode flashings. When the contractor drives away, the house often looks beautiful. However, the real damage may be just beginning.

Many cedar repair and maintenance companies do not take the painstaking approach of managing cedar roofs the way they require. Power washing can thin the cedar shakes and shingles. The average shake is ½” at the bottom. But 20″ high, at the top, the small part that is exposed to the sun may only be ¼” thick. That area wears through from sun and weather exposure. But if abrasive cleaning techniques are added, the life of the cedar may be reduced very quickly. It is critical to hire professionals who understand the unique characteristics of this roof material.

In the Portland metro environment, flat or commercial roofs have one of the toughest jobs in the exterior world. In the summer, flat roofs must resist heat and extreme UV exposure from the south. In the winter, they must keep the contents of the building dry from rain and the occasional wet snow, and they must also guard against condensation from the inside of the building due to our unique high humidity, low temperature fall, winter and spring seasons across Washington and Clackamas counties. Many flat roofs must also be able to contend with falling branches and tree debris, especially in wooded areas from Milwaukie to Hillsboro.

Due to their high expense and high likelihood of problems, we recommend a close inspection for all of these factors at regular intervals. Manufacturers often require these inspections for their roof system warranty. Staying abreast of conditions on your flat roof through inspection and performing necessary repairs may save substantial headache and wallet-ache.

Tile roofs usually come with 50-year or greater life expectancies. However, due to our unique Northwestern weather conditions throughout the Portland metro, we see leakage begin in less than 10 years of service life.

Generally speaking, most tile roofs were not designed for the Northwest climate. They are a single coverage product, meaning that they are only one layer thick on about 60% of the roof surface, while asphalt composition and cedar roofing is two-layers thick (or greater). When tile seams and joints become lined with blockage from tree debris and moss, water is naturally re-routed underneath the roofing. Most tile roofs have a paper-based felt paper that is the only thing keeping the house dry. This felt paper cannot handle long-term saturation with water. The result? Plywood damage and slow, leeching leakage that damages the roof structure.

Because of this reality, maintaining tile roofs carefully and consistently is key for homeowners throughout Lake Oswego, West Linn, Happy Valley, and the broader metro. These products have specialty coatings on them to protect them from soaking up water and from freezing, thawing and breaking. Often times, we see these coatings removed by aggressive cleaning, which also compromises the roof. Continued and diligent maintenance efforts are key to ensuring the maximum life expectancy of your tile roof.

Another unique handicap with tile roofing is the batten system. Battens are wood strips that the tiles hang on. Tile roof valleys often have battens that dam debris in the roof assembly. These, too, need attention and cleaning.

We repair and service all roofs throughout the Portland metro area. It is important to consider the two different repair approaches when we are discussing roof repairs.

There are generally two types of repair. “Temporary repairs” are repairs that do not involve complete correction of the problem. Unfortunately, most repairs in the roofing industry fall under this category. Roofers often think of repairs as a “patch.” This is a temporary perspective that does not consider a long-term objective. It is a “stop the problem now, worry about the long-term results later.”

“Permanent repairs” are when the entire problem is corrected so that the issue will get the maximal life of the roof covering. This is a quality approach. Permanent repairs require more expertise, time and effort, and often times involve a more complete approach to preparation and detail work.

Both repair approaches have their place. We recommend communication with your estimator to determine which approach they are proposing and which approach may be the best fit for you.