Modified bitumen roofing, often referred to as mod bit roofing, is a highly durable roofing system first introduced in the 1960s. Comprising a thick asphalt layer coated with protective granules, this type of roofing is typically available in rolls. These rolls are applied to the roof deck, creating a robust and long-lasting roof system that, when properly maintained, can be recoated over time to extend its lifespan.
ABOUT MODIFIED BITUMEN ROOFING
Modified bitumen roofing is a flexible asphalt material topped with granules and features a smooth underside that adheres to a base layer. Unlike roll roofing, modified bitumen is more durable and superior due to its composition and application methods. Available in rolls that are generally 3 feet wide, it is suitable for both large commercial roofs and lower slope residential areas, such as porch roofs. Various methods of application include heat application (torched down), cold adherence, hot adherence (hot tar), or self-adherence.
Modified Bitumen Roof in Arizona
The versatility of modified bitumen makes it ideal for use in various climates, including the diverse conditions found in Arizona. This roofing system can be coated with a cool roof coating to reflect sunlight better, extending its lifespan. After 10-15 years, a modified bitumen roof can be recoated with silicone or other coatings to prolong its life by an additional 5-10 years or more. Many commercial roofs, when replaced, reveal that the base layer was originally modified bitumen, showcasing its adaptability as a base coating for other roofing systems.
THE MODIFIED BITUMEN ROOFING SYSTEM
Installation Process
- Preparing the Roof Deck: Ensure the roof deck is sound and slopes at least 1/4 inch per foot. If necessary, additional framing or insulation board and taper board can be installed.
- Application Methods:
- Torched Down: A base layer, typically a self-adhering asphalt material, is installed. The modified bitumen roll is then slowly applied, heated with a torch, and compressed into the base layer. Each roll overlaps the previous one, creating a continuous roofing system that drains properly.
- Cold Adhered: A cold application compound is applied to the base layer, followed by the modified bitumen roll, which is then allowed to dry.
- Hot Adhered: Hot tar is piped to the roof, poured in sections, and the modified bitumen roll is applied into the hot tar.
- Self-Adhered: Modified bitumen with an adhesive backing is applied to the roof, although this method is less preferred due to weaker adhesion compared to other methods.
LIFESPAN AND WARRANTIES
ABOUT M&M ROOFING
M&M Roofing has been installing modified bitumen roofing systems across Arizona since 1984. Our service areas include Tucson, the Phoenix metro (Queen Creek, Gilbert, Chandler, Phoenix, Tempe, Scottsdale, Glendale, Goodyear, Avondale, Peoria, and surrounding areas), Prescott, Flagstaff, Kingman, and everywhere in between.
Frequently Asked Questions
Modified bitumen roofing is a type of asphalt-based roofing system designed for buildings with low-slope or flat roofs. It is composed of five layers, including a polymer-modified bitumen membrane, reinforcing fabrics, and surfacing materials. This roofing system is known for its durability, flexibility, and resistance to harsh weather conditions.
While modified bitumen roofing is generally durable and reliable, it can have some problems:
- Installation Issues: If not properly installed, it can lead to poor adhesion and water infiltration.
- Blistering and Cracking: Extreme temperatures can cause the material to blister or crack over time.
- Ponding Water: Flat or low-slope roofs may accumulate standing water, which can damage the roofing material.
- Maintenance: Regular maintenance is required to ensure longevity and prevent small issues from becoming major problems.
The lifespan of a modified bitumen roof typically ranges from 20 to 30 years, depending on factors such as installation quality, environmental conditions, and regular maintenance. Proper care and timely repairs can help maximize the roof’s lifespan.
Despite its advantages, modified bitumen roofing has some disadvantages:
- Cost: It can be more expensive to install compared to some other roofing options.
- Weight: Modified bitumen is heavier than other roofing materials, which may require additional structural support.
- Environmental Impact: The production and disposal of bitumen can have environmental consequences.
- Limited Aesthetic Options: It offers fewer aesthetic choices compared to other roofing materials like shingles or tiles.