Home › Learn From The Pros › The Causes and Effects of Underlayment Failure The Causes and Effects of Underlayment Failure May 25, 2022 Your roof is composed of several components that work together to protect your home. Each of these parts plays specific functions, which are essential for a strong and long-lasting roof. One of these critical roofing components is the underlayment. This part of your roofing system is hidden from plain view, so it’s commonly overlooked. That said, make sure to pay close attention to your underlayment to ensure optimal roof performance. What Is Roofing Underlayment? Roofing underlayment is laid on the surface of your roof deck before shingles are installed. It is responsible for protecting your roof deck against water infiltration, heat, snow, strong winds and other elements. With proper roofing underlayment, leaks can be more manageable in case the shingles fail. Your decking also becomes more resistant to rot, mildew and mold. That is why your underlayment should be laid evenly across roof decks to provide the best protection. Three main types of roof underlayment are available on the market: Asphalt-saturated felt: This type of underlayment is also called felt paper or tar paper. Although this type of underlayment is no longer the most popular underlayment material nowadays, it can still be found in some properties. Before the emergence of synthetic products, asphalt-saturated felt was the top preference of homeowners. Its base mat is made of cellulose and polyester, and it is mixed with bitumen or asphalt for water resistance. One of the main reasons why it’s still being installed by roofing contractors today is because it comes in varying thicknesses. The standard thickness provides adequate resistance to outdoor elements, but thicker ones provide better protection against damage and weather exposure. Synthetic underlayment: Also known as non-bitumen synthetic underlayment, this type of underlayment is currently the industry standard for many homes and buildings. It’s made up of a synthetic base mat that’s saturated in asphalt and then mixed with fiberglass. It has stronger water resistance than asphalt-saturated felt, and the addition of fiberglass provides excellent tear resistance and stability. Rubberized asphalt underlayment: This is the most expensive type of underlayment that you can use. Its base mat is also saturated with water-resistant material. But unlike the other two types of underlayment, rubberized asphalt is filled with higher percentages of asphalt and rubber polymers, making it waterproof. Overall, when it comes to protection and performance, this underlayment is the best. However, roofing contractors usually charge higher upfront costs for this underlayment material. How Does the Underlayment Fail? In general, the underlayment is durable, but it can fail depending on certain conditions. Below are the common causes of underlayment failure: Poor Installation Regardless of the type of underlayment you have installed on your roof, it won’t be effective and durable if its installation was not properly done. Even the best underlayment material can fail if it was installed poorly by your contractor. When it comes to roof repair and replacement contractors, always choose a company with experience and a good reputation. Beware of roofers with little to no experience or companies that offer unreasonably low prices for their services. Always do your research before hiring a contractor. Check customer reviews, and ask for references. Poor Material Sometimes, even if the installation is done properly, the underlayment may still be unable to last long if the material isn’t up to par. If the base mat of the underlayment you chose can’t stay intact or is highly susceptible to tearing, your roof could get damaged when heavy rains or strong winds batter your home. Make sure to purchase roofing underlayments made by reputable manufacturers. Furthermore, ensure that your contractor knows how to properly install the underlayment that will be used in your roofing system. What Are the Effects of Underlayment Failure? If you fail to address underlayment damage and the material fails, these are some issues you might encounter: Structural Problems Leaks and issues on your underlayment give way for moisture and the elements to penetrate your roof’s structural support. If not addressed immediately, you’re going to have to deal with problems like wood rot caused by moisture and other types of damage that will compromise the integrity of your roof. Moreover, the underlayment isn’t supposed to be exposed to water for a long period. If it happens to absorb too much moisture, it’ll become heavy and strain your roofing system even more. Your roof will eventually require a major roof repair because of this. More Leaks Once your underlayment fails, you’re going to have more leaks in various areas of your home. Water travels quickly, and if it is not stopped early, it will spread into your walls and ceilings, causing stains, leaks and other moisture-related problems to your roof and other parts of your home. Mold Mold tends to form in dark and damp conditions, and a compromised underlayment is an optimal place for it to grow. Roofing materials can prevent moisture from drying out, and the hot and humid air coming from your attic can further encourage the growth of mold spores. A small amount of mold is already a significant concern that needs to be taken care of immediately. And since the underlayment is typically unseen, your mold problems could become extensive over time. Furthermore, the growth of mold can also weaken the affected roofing materials. To avoid underlayment failure, it’s best to regularly schedule roof inspections and ensure they’re done by reputable professionals. These inspections go beyond your underlayment as they cover your entire roofing system. Experts can spot issues that might be missed by the untrained eye and detect minor problems that you can deal with before they become even more problematic. Since 2005, Neumann Construction has been providing high-quality roof replacement and other roofing services to local communities. Our workers are highly experienced, well-trained and dedicated to providing you with the results you expect and need. Get a roofing quote by filling out our contact form or by calling us at (218) 270-0009. We provide services in the areas in and around Brainerd, MN.