All About Asphalt Roof Underlayment When Replacing a Roof
Asphalt Roof Underlayment
The Importance of Asphalt Roof Underlayment
Every homeowner knows how a structurally sound roof is critical to the integrity and beauty of their home. Your roof keeps your family safe from inclement weather, protecting your attic and allowing for sufficient ventilation. It also insulates your home from the cold in winter and excess heat in summer. Roofing underlayment plays a critical role in an asphalt shingle roof. So, when it's time for a roof replacement, it makes sense to look for the best asphalt roof underlayment available.
Your asphalt roof underlayment keeps your roof dry and protected. Read on to learn all about asphalt roof underlayment when replacing a roof.
So, What is Roofing Underlayment?
Roofing underlayment is a barrier material that fits between the roof deck and the shingles. It functions as additional insulation to your home while acting as a waterproof barrier to prevent moisture from entering your attic and potentially causing damage. It is one of the most overlooked roofing components.
Your home's roof deck, also known as roof sheathing, is typically plywood, OSB, or step sheathing. The decking is nailed onto the rafters to help stabilize and give structure to the entire roof. Asphalt roof underlayment is placed on top of the sheathing material and provides a secondary layer of protection should any water get under the shingles.
Three Types of Asphalt Roof Underlayment
There are three basic types of asphalt roof underlayment: asphalt-saturated felt, rubberized asphalt, and synthetic underlayment. Each has benefits, and the type you ultimately choose depends on your roofing contractor, where you live, and your local building codes and regulations.
1 - Asphalt-Saturated Felt
This is one of the oldest types of roofing underlayment. It is also referred to as tar paper or felt paper. It is an organic mat or paper saturated with asphalt to promote water resistance. It is available in two standard weights (15 or 30 pounds).
Asphalt-saturated felt is the most affordable underlayment option. It improves the durability of the roof deck, protecting it against impact damage from hail or debris like tree branches. No.15 is best for light-duty, for example, roofing a shed or outbuilding. No.30 is the best option for protecting your home from the elements.
2 - Rubberized or Self-Adhesive Asphalt Roof Underlayment
Rubberized asphalt is the best option for protecting premium roofing, leak prevention, and extreme temperatures. Rubberized asphalt underlayment is self-adhering, self-healing, patchable, and great for variable climates.
A rubberized asphalt underlayment is a high-quality option that offers the highest level of waterproofing. It's ideal for use around leak-prone areas, like eaves, valleys, chimneys, skylights, and vents. Its role is to help prevent water damage. The composition is primarily rubber polymers and asphalt, but the formula varies from manufacturer to manufacturer.
Because of its variable composition, it can be chemically altered to improve waterproofing, fiberglass reinforcement, or sound absorption. If it is damaged or leaks, rubberized asphalt can be patched. It is the most expensive asphalt roof underlayment option. Its self-adhesive property helps form a waterproof seal, and its composition allows it to expand and contract without cracking or breaking.
3 - Synthetic Underlayment
Synthetics offer durability, tear resistance, and mold resistance. It also offers high heat tolerance, is recyclable, and goes on fast. Synthetics are also easy to walk on and provide reliable water resistance.
This is the newest underlayment option available. Underlayment synthetics are made from woven or spun polyethylene or polypropylene for improved durability and tear resistance compared to saturated asphalt. This type of underlayment costs more to install than asphalt-saturated felt but is not as expensive as rubberized asphalt.
Synthetics are an excellent option if you are looking for a less expensive underlayment without sacrificing durability. While it doesn't offer waterproofing levels of rubberized asphalt, it is still very adequate. If your home is prone to mold, synthetics are recommended because they repel water and are inert to mold. Synthetic asphalt roof underlayment is gaining popularity thanks to its anti-slip properties and elasticity.
Choosing the Right Asphalt Roof Underlayment
When choosing an underlayment material, consider several critical factors. These include your local climate, top roof layer material, durability, water resistance, and cost.
Climate – Local climate affects any material installed outdoors because it is exposed to seasonal temperature changes. Asphalt-saturated felt is an excellent option if you live in an area with relatively constant temperatures. However, if you have the budget, rubberized asphalt is the best choice to stand up to the Minnesota climate.
Type of Roof – Asphalt-saturated felt and rubberized asphalt work well with asphalt roof shingles. Rubberized and saturated asphalt underlayment is also suitable for slate shingles. For a metal roof, it's recommended that you invest in synthetic underlayment. It is more heat-resistant than either rubberized or asphalt-saturated material.
Durability – Synthetic roof underlayment is best if durability and tear resistance are necessary. However, if waterproofing is more important, spend a little more and install rubberized asphalt.
Cost – Asphalt-saturated underlayment is the most affordable choice if cost is a factor. Synthetic underlayment is the next step up in price, with rubberized asphalt being the most expensive option.
If you have the budget, rubberized asphalt offers the best waterproofing and durability in weather extremes. It is also the longest-lasting type of underlayment, offering a usable life of 25 to 35 years. If you're unsure which underlayment is best for your home, your roofing contractor can educate you on your asphalt roof underlayment options and what your local building codes require.
Do you need a new roof? Do you live in Waseca, Freeborn, or the neighboring Counties in Southern Minnesota? Then you owe it to yourself to call Rooftop Solutions at (507) 400-7663. With 50+ Five-Star Google Reviews, we are not your typical fly-by-night, subcontract-it-out roofing contractor. We are always happy to answer all your asphalt roofing underlayment questions.
