Are you thinking about installing a new roof or upgrading your current one? Selecting the right roof underlayment is essential. While many homeowners concentrate on shingles or tiles, the underlayment installed below it is also vital. It shields your home from water damage, offers an additional line of defense against the weather, and boosts your roof’s durability.
Now, let’s explore various types of roof underlayment along with their pros and cons.
What Are The Different Types Of Roofing Underlayment?
Lets delve in and take a look at the best roof underlayment options for your home:
#1. Asphalt-Saturated Felt Underlayment
Residential roofers often turn to asphalt-saturated felt as a cost-effective choice. This material, made from an organic or fiberglass base, is saturated with crude oil byproducts, which provides the material with water resistance.
There are two main types, called #15 and #30, with the latter being more durable. This underlayment adds an extra layer of defense against rain and snow, making it a favored option among roofers and architects alike for its reliability and straightforward installation.
| PROS | CONS |
| Cost-Effective: Affordable choice for roofing projects | Susceptibility to Damage: Easily torn, especially in high winds |
| Moisture Resistance: Protects against water damage | Limited Lifespan: Shorter lifespan compared to synthetic or rubberized asphalt options |
| Ease of Installation: Simple installation with basic tools like nails or staples | Vulnerable to UV Rays: Degrades quickly when exposed to heat and sunlight, increasing fragility |
| Temporary Weather Protection: Shields against wind, rain, and hail during installation | Added Weight: Heavier than synthetic alternatives, potentially increasing the weight on the roof |
| Protective Layer: Safeguards roof components and enhances safety during installation |
#2. Peel And Stick Roof Underlayment
Peel and stick roof underlayment is a type of self-adhering, synthetic waterproof underlayment that is installed under roofing materials like shingles, metal, or tiles. It protects against water from ice dams, wind-driven rain, and other weather elements.
Using rubberized asphalt technology, it seals tightly around nails for a leak-resistant barrier. Its slip-resistant surface provides a safer surface for roofing contractors to work during installation. Strategically placed around roof edges, valleys, and penetrations, it reinforces flashing to protect the roof deck and interior from water damage.
| PROS | CONS |
| Ease of Installation: No additional fasteners needed, reducing the risk of leaks | Cost: Typically more expensive than traditional options like felt paper |
| Excellent Adhesion: Forms a strong, watertight seal with the roof deck | Limited Repositioning: Once applied, adjustments can be challenging, requiring precise installation |
| Durability: Resistant to extreme weather conditions |
#3. Rubberized Asphalt Underlayment
Made from a blend of rubber polymers and asphalt, this roofing underlayment is known for providing the best waterproofing capabilities. It creates a strong barrier against moisture, offering superior protection compared to other options.
Despite being more expensive, it’s easy to install and can last up to 50 years due to its durability and resistance to UV rays, cracking, and weather changes. This peel-and-stick product adheres directly to the roof deck, forming a tight seal without needing nails, effectively keeping water away from the decking.
| PROS | CONS |
| Waterproof and Durable: Excellent barrier against moisture, enhancing the roof’s lifespan | More Expensive: Higher cost compared to traditional asphalt-saturated felt |
| Mold and Mildew Resistant: Resistant to mold and mildew growth, creating a healthier roofing system | Limited Breathability: Moisture can become easily trapped behind the underlayment in certain conditions |
| Self-Adheres for Easy Installation: Simplifies installation with a secure seal | Heavier: Some versions are heavier than synthetic alternatives |
| Resistant to Extreme Temperatures: Withstands varying weather conditions without degrading | Challenges With Adhesive Backing: Extreme temperatures can affect the adhesive’s performance |
#4. Synthetic Underlayment
The next option is synthetic underlayment, made from materials like polyethylene, polypropylene, and fiberglass, which serves as a durable, water-resistant barrier between the roof deck and roofing materials.
It’s lighter and more tear-resistant than traditional asphalt-saturated felt, offering better UV resistance and durability against rotting or deterioration. This type of underlayment also provides improved traction for workers during installation. Although it comes at a higher cost compared to asphalt-saturated felt, it’s still cheaper than rubberized asphalt, providing a good in-between option for those who don’t want to sacrifice quality over cost.
| PROS | CONS |
| Durability: Resists harsh weather conditions and UV rays, offering long-lasting protection. | Cost: Initial cost is higher than traditional felt paper, though offset by long-term durability. |
| Lightweight: Easier to handle during installation, reduces stress on the roof’s structure. | Installation Skill: Requires skill and attention, may be challenging for DIY projects. |
| Traction: Textured surface provides superior grip for roofers on steep slopes. | Puncture Risk: Can be susceptible to punctures during installation without careful handling. |
| Versatility: Compatible with various roofing materials, enhancing flexibility. | Traps Moisture: Inadequate ventilation can lead to moisture issues like mold or rot. |
| UV Resistance: Does not degrade when exposed to sunlight. | Environmental Impact: Some materials may not be eco-friendly, so choose options carefully. |
| Water Resistance: Virtually waterproof, preventing moisture infiltration and rot. |
What’s An Ice and Water Shield?
An ice and water shield is slightly different from roof underlayment as it’s completely waterproof, whereas underlayment is only water resistant. However, we’ve included it here because they can be utilized together to specifically protect against water intrusion from ice dams and wind-driven rain. It features a rubberized asphalt adhesive layer supported by a slip-resistant, high-density polyethylene film.
The ice and water shield can be applied to the roof deck, or on top of the underlayment in vulnerable areas such as roof valleys or anywhere water tends to collect on your roof. No matter the type of roofing material you’re installing on your home, an ice and water shield is a great additional layer of protection.
| PROS | CONS |
| Enhanced Leak Protection: Creates a waterproof barrier, even with damaged roofing materials. | High Cost: More expensive per square foot compared to other options |
| Extends The Roof’s Lifespan: Safeguards vulnerable areas, prolonging the life of the roof | Difficult Removal: Adhesive makes removal challenging during re-roofing |
| Code Compliant: Meets building code requirements for specific roof areas | Installation Challenges: Must be applied directly on the roof deck for effectiveness |
| Easy Installation: Flexible and lays flat, simplifying installation |
Can Underlayment Be Applied Over Existing Shingles?
If you’re re-roofing your home you may be wondering if you can install another layer of shingles over the old ones, and if so, whether underlayment can also be installed too.
Underlayment should never be applied directly over existing shingles. Its main purpose is to protect the roof deck from anything that gets past the shingles so it makes it counterintuitive to install underlayment over old shingles. This would also produce an uneven surface for the next layer of shingles, and increase the risk of premature wear and leaks.
The proper procedure is to strip the old roof all the way down to the roof deck, thoroughly inspect and repair any damage, and then install a new layer of underlayment before applying the new shingles.
Can You Install Roof Underlayment Yourself Or Is Hiring A Professional Better?
DIYers with roofing experience can install roof underlayment themselves, but hiring a professional is often recommended to ensure proper installation that is in accordance with building codes and manufacturer specifications.
Professionals are equipped to handle complexities such as roof slope and material compatibility, ensuring that the underlayment is effective at protecting your roof in the long run.
Conclusion
Choosing the right type of roof underlayment is important for long-term roof performance. By understanding the pros and cons of each type mentioned above, you can make the best decision that fits your project’s needs and budget. Consulting with a professional roofing contractor ensures you select the best underlayment for your specific roof, ensuring reliable and lasting protection for your home.
If you’re looking for reliable roofing services, Empire Roofing & Exteriors is your answer. Specializing in new installations, repairs, and replacements, we offer the best services to ensure your home is well-protected. Contact us today at (225) 347- 8877.