The underlayment, also known as roofing felt, is the protective barrier that is installed between the outer roofing material and the roof deck. It’s what keeps your attic dry if the outer roofing layers fail. One of the most common types of underlayment is asphalt-saturated felt. In today’s blog, roof installation contractor Affordable Roof Care takes a look at this indispensable component.
What Is Asphalt-Saturated Felt?
Despite the availability of other materials such as rubberized asphalt and synthetic underlayment, asphalt-saturated felt remains a popular choice. Traditionally, it’s made from pulped waste paper and cloth. The resulting sheets are then saturated with asphalt for water resistance. Underlayment made from paper is still available, and is now known as “organic” felts, while modern ones are made from fiberglass.
Roofers strip the roof down to the roof deck during roof replacement. Once the decking is inspected (and repaired, if necessary), the underlayment is then installed. The specifics vary depending on the roofing system, but underlayment usually comes in rolls, which installers then nail onto the roof deck. Overlaps are required as allowance for thermal expansion and contraction. Pre-installed adhesive may also be used at the seams for better moisture protection. Flashing is then installed at the edges, and the outer roofing is installed on top.
Not all asphalt-saturated felts are made the same. Poor-quality underlayment may contain less asphalt than it should, which could lead to water absorption and damage to the decking material and/or the asphalt shingle backing mats. Being hidden from sight, spotting the damage as it happens is unlikely. Another potential problem with subpar underlayment is the offloading of volatile compounds, which could seep into the attic and into your living space. Emission can be accelerated by a combination of heat and reaction to the outer roofing material.
To get the best kind of underlayment for your roof, make sure you hire a licensed and insured roofing contractor, preferably one who holds certification from major manufacturers. This is your assurance that the roofing felts – along with the other components of your roof – are compliant with industry standards, and therefore will be less likely to cause problems.
To learn more about our roof repair, maintenance and installation services, call Affordable Roof Care today at (360) 639-4339. You can also fill out our contact form to schedule a free, no-obligation estimate. We serve many areas in and near Port Orchard and Bremerton, WA.