Roof underlayment is a vital part of a roofing system to protect homes and buildings from moisture and water damage, wind, and other elements. While customers might focus on choosing a roofing material, such as tile or metal, for a new roof, what should they know about choosing a type of underlayment?
When roofs need new underlayment during a roof replacement or new installation, the type to choose depends on different factors. Roofing contractors can discuss how to choose the right type of underlayment with customers using the following explanations. These factors determine the best underlayment for tile, metal, or shingle roofs.
The thickness of underlayment plays a role in which type to choose for different roofs. For example, underlayment for a tile roof is usually a 50 mil thick or more asphalt-based rolled product. Depending on other factors, shingle and metal roofs might require a different thickness. Remember that underlayment with a higher thickness weighs more than underlayment with a lower thickness.
Metal and tile roofs can typically handle higher thickness underlayment. However, shingle roofs might need a more lightweight underlayment with a lower thickness. Roofing felt underlayment typically comes in 15-pound and 30-pound thicknesses. 30-pound underlayment offers better protection from the elements.
When choosing underlayment for a roof replacement or a new roof, the product material can affect this decision. Underlayment can be made of organic, fiberglass, or polyester substrates that are either saturated or coated with standard asphalt or polymer-modified asphalts, such as SBS or APP. Comparing these options and considering other factors helps determine the best underlayment for tile, metal, or shingle roofs.
3. Region, Building Codes, and Application Type
When helping customers choose the right underlayment for a new roof, their region, local building codes, and application type should all be considered. The best underlayment for roofs varies by region when local weather conditions and climate are factored into this decision.
Local building codes also determine which underlayment should be used. Building codes in some places generally require felt underlayment weighing 15 pounds or more to be installed on new roofs. It’s best to check local building codes when deciding which kind of underlayment to use with a roof installation or roof replacement. Application type can also make a difference in the underlayment that works best for a new roof.
4. Local Climate
The climate where a home or building is should be considered when deciding on an underlayment. Roofs in a wet, cold climate need underlayment that isn’t as vulnerable to freezing temperatures and snow and ice.
Tile and metal roofs generally work better with high-temperature roof underlayment since it provides better protection from leaks and ice dams. Underlayment for metal typically has a higher temperature rating than tile. Shingle underlayment usually does not have a high-temperature rating.
The best underlayment for homes and buildings in hot, dry climates should withstand heat exposure without warping, cracking, or damaging. In this climate, tile and metal roofs are commonly used due to their ability to withstand hot temperatures and prevent heat from seeping into attics.
5. Roof Covering and Permeability
Product permeability is another factor to consider when choosing underlayment for tile, metal, or shingle roofs. Permeability refers to how much moisture can seep through underlayment. Higher permeability means more water can get through, while lower permeability means less moisture can get through.
The type of roof covering can affect permeability. Shingle roofs typically have greater permeability compared to metal and tile roofs. Moisture and heat can more easily move through shingle roofs, while metal and tile roofs block these elements better.
Since felt underlayment has higher permeability, pairing it with the right roof covering is essential. For example, felt underlayment and a shingle roof covering let higher amounts of moisture and heat through. Pairing underlayment with a metal roof covering results in lower permeability overall.
When purchasing roofing supplies for customers, please contact Fontana Roof. We have a wide range of high-quality roofing underlayment products available.