Roof underlayment refers to the first layer of material that is laid on the roof structure before the roofing panels are installed. Underlayment is essential for metal roofs as it protects the roof panel from unevenness and resins, and offers additional protection against the weather elements. The common types of underlayment on the market today are felt and synthetic underlayment. Their performance, costs, and installation requirements are distinct; however, choosing between them can be a daunting task, especially if you are not aware of their features. Read on to find out more about these materials and how to choose the ideal one for your metal roofing project.
Felt underlayment, commonly known as felt paper, has been around for decades. It can be infused with layers of asphalt or fiberglass depending on the type that you choose. Both options offer the same benefits and are cost-friendly. Felt is suitable for metal roofs with a steep slope, as it lies flatter as compared to when used on flat roofs. Felt underlayment is available in various configurations, including organic reinforced and inorganic reinforced. Inorganic felt underlayment is a better choice as it lies flatter and stands better than the organic one.
Although felt underlayment has been around for ages, it is not without faults. It usually sticks to the metal and provides little resistance to water infiltration, especially around the fasteners. It does not serve as an effective air barrier; therefore, if your roof isn't insulated, it can contribute to increasing your heating and cooling costs. This material is best suited for buildings in areas with an arid climate or low moisture loads.
Synthetic underlayment is a modern material that's made of polyethylene and other plastic compounds. Roofing contractors prefer it due to its lightweight nature, water and moisture resistance, and ease of installation. It does not stick to the metal and is watertight around the fasteners. Unlike felt which can be difficult to work with, synthetic underlayment offers faster and more efficient installation, and this can cut down the labor costs significantly.
On the downside, synthetic underlayment can be costlier than felt underlayment. However, with reduced labor and installation costs, you may end up spending less as at the completion of the project. Also, since it's watertight, it does not offer protection against moisture buildup on the roof deck and patio. You may need insulation to prevent the effects of moisture build up beneath the roof.
Choosing the right underlayment is essential in the construction of a durable and functional roof. Whichever material you choose for the underlayment, ensure that you hire professional roofing contractors for the installation requirements.