Commercial Roofing System Types Installed Across Texas
Low Slope vs. Steep Slope Roofing: Which System is Right for Your Commercial Property?
Choosing the right roofing system for your commercial property starts with understanding the fundamental difference between low slope and steep slope systems. Most commercial buildings in Texas, including warehouses, office buildings, retail centers, multi-family complexes, and student housing, use low slope systems. Steep slope systems are more common on institutional buildings, churches, and commercial properties requiring a traditional architectural appearance.
At Mattco Roofing and Construction, we install both low slope and steep slope systems across College Station, Bryan, Houston, and Austin. Our certified installer status with 13 leading manufacturers means we can recommend the right system for your building, your budget, and your long-term capital plan.
Low Slope Roof Systems
When envisioning a low slope roof, one might picture a
surface that appears nearly level. In reality, low slope roofs are designed
with a slight incline to facilitate water drainage. This roofing style has
gained popularity, especially in urban settings, due to its sleek and modern
aesthetic. But what truly makes a low slope roof an appealing choice, and when
might it be the perfect fit for your commercial property?
Advantages of Low Slope Roofs
Maximized Space Utilization: One of the most compelling
advantages of low slope roofs is their ability to provide additional usable
space. This area can be transformed into a rooftop garden, an outdoor lounge,
or a convenient location for HVAC units, all while maintaining the aesthetics
and functionality of the building.
Cost-Effectiveness and Ease of Installation: Generally, low
slope roofs are less expensive to install than their steep sloped counterparts.
Their simpler structure requires fewer materials and can be constructed more
quickly, leading to reduced labor costs. Additionally, the ease of access makes
maintenance tasks, such as gutter cleaning and roof inspections, simpler and
safer.
Disadvantages of Low Slope Roofs
Water Drainage Challenges: The most significant challenge
with low slope roofs is water drainage. Unlike steep sloped roofs, which
naturally guide water and debris to the ground, low slope roofs can allow water
to pool if not properly designed or maintained. This can lead to leakage and
increased wear and tear over time.
Limited Material Options: Low slope roofs typically require
specific types of materials that differ from those used in steep sloped roofs.
These materials need to be more resistant to water pooling, which can limit
options in terms of aesthetics and cost.
Ideal Scenarios for Choosing a Low Slope Roof
Low slope roofs are particularly suitable for commercial
buildings due to their space-efficient design and cost-effectiveness. In urban
environments, where space is at a premium, a low slope roof can provide that
extra area for various functionalities or leisure activities.
Mattco installs all major low slope roofing systems across College Station, Bryan, Houston, and Austin. We work with building owners and property managers to select the right membrane, insulation, and drainage system for each property based on roof size, existing substrate, local climate conditions, and warranty requirements.
Types of Flat Roof Systems
TPO
(Thermoplastic Olefin)
TPO is a single-ply roofing membrane known for its heat-reflective properties and energy efficiency. It is a popular choice for commercial low slope roofs.
- Materials Used: TPO roofing is made from a blend of polypropylene and ethylene-propylene rubber. It is known for its heat-reflective properties and resistance to UV radiation.
- Installation: TPO membranes are installed in large rolls and typically secured with mechanical fasteners or adhesive. The seams are welded together using hot air.
- Benefits: TPO roofs offer excellent energy efficiency due to their reflective properties, which can reduce cooling costs. They are also resistant to UV rays, chemicals, and punctures.
- Considerations: TPO roofs may be more expensive compared to other options, and their performance can vary based on the quality of the material and installation.
Modified Bitumen
(MOD BIT)
MOD BIT is an asphalt-based roofing system reinforced with polyester or fiberglass and modified with SBS or APP polymers for improved flexibility and durability. It evolved from built-up roofing and has been widely used in commercial construction for over 50 years.
- Materials Used: Modified bitumen membranes are made from asphalt blended with polymerized rubber or plastic and reinforced with fiberglass or polyester fabric. The two main types are SBS (Styrene-Butadiene-Styrene), which remains flexible in cold temperatures, and APP (Atactic Polypropylene), which provides excellent UV resistance and heat tolerance.
- Installation: Modified bitumen is installed in multiple layers, typically a two-ply system. Installation methods include torch-applied, where an open flame heats and bonds the membrane; cold-applied, using adhesive; and self-adhered peel-and-stick systems. Torch application by experienced professionals produces the most durable result.
- Benefits: Modified bitumen offers exceptional thickness and waterproofing redundancy. A standard two-ply system provides 240 mils of membrane thickness compared to 60 mils for a single-ply system. It performs well on roofs with high foot traffic, handles temperature swings without cracking, and is straightforward to repair.
- Considerations: Dark-colored mod bit membranes absorb heat, which can increase cooling costs in Texas summers. Torch application requires experienced contractors and proper fire safety protocols. Lifespan typically ranges from 15 to 25 years depending on installation quality and maintenance.
EPDM
(Ethylene Propylene Diene Monomer)
EPDM is a synthetic rubber roofing membrane with one of the longest proven performance records in commercial roofing, having been used on flat and low-slope roofs for over 60 years.
- Materials Used: EPDM is formulated primarily from ethylene and propylene derived from natural gas, with diene added for flexibility and UV resistance. It is available in black or white membranes in thicknesses ranging from 45 mil to 90 mil. Wider sheet widths up to 50 feet reduce the number of seams on large commercial roofs.
- Installation: EPDM can be installed using three methods: fully adhered with bonding adhesive, mechanically fastened with plates and fasteners, or ballasted with stone. Large sheet sizes mean fewer seams compared to other systems, reducing potential leak points. Seams are sealed with liquid adhesive or seam tape.
- Benefits: EPDM offers outstanding durability, with properly maintained systems lasting 30 to 50 years. It is resistant to UV radiation, ozone, extreme temperature swings, and hail impact. White EPDM membranes reflect heat and reduce cooling costs, making them well suited for commercial properties in Texas. EPDM is also recyclable and contains no chlorine.
- Considerations: Black EPDM absorbs heat rather than reflecting it, which is a real factor in Texas climates where cooling costs already run high. Adhesive-based seams degrade over time and are more vulnerable to wind-driven rain compared to heat-welded seams used in TPO and PVC systems. Seam quality and installation method are critical to long-term performance.
PVC
(Polyvinyl Chloride)
PVC is a single-ply thermoplastic roofing membrane that has been used on commercial buildings since the 1960s. It is particularly well suited to industrial and food service facilities due to its outstanding chemical resistance.
- Materials Used: PVC membranes consist of two layers of polyvinyl chloride reinforced with a polyester scrim between the layers. Plasticizers are added for flexibility and UV stabilizers are incorporated to prevent degradation from sun exposure. Most PVC membranes are white or light colored, providing natural heat reflectivity.
- Installation: PVC membranes are installed in large rolls and can be mechanically fastened, fully adhered, or installed with fleece-backed products. Seams are heat-welded using hot air, creating a continuous watertight bond that is stronger and more durable than adhesive-based seam systems. This makes PVC one of the most reliable systems for seam performance.
- Benefits: PVC offers excellent chemical resistance, making it the preferred choice for restaurants, commercial kitchens, industrial facilities, and any building where grease, oils, or chemical exhaust contacts the roof surface. It is fire resistant, highly reflective for energy efficiency, and delivers a lifespan of 20 to 30 years with proper maintenance. Heat-welded seams provide superior wind uplift resistance.
- Considerations: PVC has a higher upfront cost compared to TPO and EPDM. In extreme cold climates the membrane can become less flexible, though this is less of a concern in Texas. PVC contains chlorine and some environmental programs favor TPO or EPDM for sustainability goals. Plasticizers in older PVC membranes can migrate out over time, which is why modern formulations have improved significantly.