WHAT IS ROOF UNDERLAYMENT?
Underlayment, sometimes described as felt, comes in a wide variety of materials and with many options.
From basic, 15 lb felt to upgraded, synthetic materials, the underlayment performs several important roles in your roofing system.
What is roof underlayment?
Before we talk about what it does, let's talk about what underlayment is and is not. Underlayment is a thin layer a material consisting of felt, fiberglass, asphalt, or other synthetic materials. When installing underlayment, it should be rolled out in horizontal rows along your roof deck prior to the installation of your shingles.
While your underlayment can have some water shedding abilities, depending on the quality of the material used, it's not intended to protect your roof from water damage. Instead, it performs several key functionalities.
What does roof underlayment do?
First, it protects your shingles from harmful resins that may be found in the wood of your roof deck. These resins can cause damage to your shingles, bringing about the early deterioration of your shingles.
Next, underlayment helps to create a flat and even deck surface for which to adhere your shingles to. This allows your shingles to sit evenly for optimal water shedding performance and an enhanced look.
Finally, the underlayment material creates a breathable layer, or space, between your roof deck and shingles, thereby reducing moisture that can become trapped beneath your shingles. Without this layer, condensation could form causing premature aging to your shingles and roof deck.
While you will never see the roof underlayment once your shingles are installed, this material plays an important role in the life of your roofing system. When considering a roofing contractor, ensure they are using the appropriate underlayment and installing it correctly.
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