Considerations for Exterior Trim
When selecting exterior trim materials, several factors come into play.
-
Durability is a primary concern, as materials must resist moisture, insects, and temperature fluctuations to ensure longevity.
-
Maintenance requirements vary significantly; some materials require frequent painting or sealing, while others are virtually maintenance-free.
-
Another crucial factor is aesthetic appeal, as the trim should complement the architectural style and finishes of the structure.
-
Additionally, installation challenges, such as weight, cutting methods, and fastening requirements, can affect labor costs and complexity.
-
Finally, cost and availability influence the decision-making process, as budget constraints and regional accessibility play a role in selecting the most suitable material.
Overview of Exterior Trim Materials
Wood Trim
Wood trim has been a standard in construction for centuries. It’s valued for its natural beauty, many uses, and easy procurement. Wood trim can be used on Colonials, Victorians, Tudors, and other historic architecture. It offers warmth and depth that synthetic materials can’t always replicate.
Wood trim's primary advantage is its high customization level; you can paint or stain it to match many architectural styles, making it a timeless choice for pieces like:
-
Window and Door Casings
-
Fascia and Soffits
-
Corner Boards
-
Decorative Moldings
-
Columns and Post Wraps
-
Shutters
-
Board and Batten Trim
-
Eaves and Overhang Details
However, to prevent deterioration, wood requires regular maintenance, including sealing or painting. Over time, it’s also vulnerable to warping, cracking, and termite damage, making it a less durable option than modern alternatives. Despite these drawbacks, wood remains preferred for some traditional homes, historical restorations, and high-end custom projects where traditional materials are a priority.
Engineered Wood Trim
Engineered wood trim is a cost-effective alternative to solid wood, manufactured using wood fibers and resins to enhance stability and minimize natural imperfections. It’s often pre-primed for easier finishing and can convincingly mimic the appearance of real wood. One of the most significant advantages of engineered wood is its affordability, making it a popular choice for budget-conscious projects and suburban housing developments.
-
Window and Door Trim
-
Fascia and Soffits
-
Corner Boards
-
Belt Courses and Band Boards
-
Skirt Boards
-
Porch and Column Wraps
-
Garage Door and Entryway Trim
However, it’s susceptible to moisture-related swelling and delamination if not properly sealed, limiting its durability in humid climates. While engineered wood offers many of the visual benefits of solid wood, its lifespan and maintenance requirements must be carefully considered in project planning.
Fiber Cement Trim
Fiber cement trim is composed of cement, sand, and cellulose fibers. It is known for its exceptional durability and resistance to environmental damage. Fiber cement is also fire-resistant, insect-proof, and highly durable, making it a strong contender for long-lasting trim applications. Additionally, it can convincingly replicate the look of wood, offering an attractive alternative without the drawbacks of natural materials.
Its weight and cutting requirements make installation more labor-intensive, often needing specialized tools. Silica dust produced during cutting also requires protective measures, adding to installation complexity. Despite these challenges, fiber cement is an excellent choice for high-moisture climates, fire-prone areas, and commercial projects where longevity and minimal maintenance are priorities.
It’s often used in:
-
Window and Door Trim
-
Fascia and Soffits
-
Corner Boards
-
Column Wraps
-
Belt Courses and Band Boards
-
Skirt Boards
-
Trim for Fiber Cement Siding
Cellular PVC Trim
Cellular PVC trim is a synthetic material designed for maximum durability, making it ideal for areas exposed to harsh weather conditions. Unlike wood, it’s impervious to moisture and insects, ensuring a long lifespan with minimal upkeep. It can also be shaped and routed for specific designs, making it highly customizable. With a high flexural modulus of 130,000 psi, it resists bending and warping better than traditional wood.
Keep in mind, PVC can expand and contract in extreme temperatures, requiring proper installation to prevent gaps. It also has a higher initial cost than wood or fiber cement. Cellular PVC is particularly well-suited for coastal homes, modern construction, and projects that require long-lasting, low-maintenance materials.
When painted in darker colors (with a Light Reflective Value (LRV) of 56 or less), a solar reflective paint should be used to mitigate the risk of thermal expansion and contraction. It also has a higher initial cost than wood or fiber cement. Cellular PVC is particularly well-suited for coastal homes, modern construction, and projects that require long-lasting, low-maintenance materials.
Fiberglass (GFRP) Trim
Due to its strength and minimal maintenance requirements, you’ll often see fiberglass used for columns and cornices. It’s exceptionally durable, resistant to rot and pests, and available in structural and decorative configurations. Fiberglass can also mimic stone or other high-end materials, making it an excellent choice for various applications.
Common applications include:
-
Structural columns and beams
-
Large cornices and moldings
-
Custom architectural elements for modern and classical designs
It offers high load-bearing capabilities with a flexural strength of 20,000 psi and tensile strength of 18,000 psi. It is also Class A flame-retardant, making it ideal for fire-resistant applications. However, it’s heavier than PVC and requires specialized fasteners and installation techniques to ensure stability. This makes it a preferred option for large-scale projects, classical architecture, and applications requiring highly durable trim solutions.
Glass Fiber Reinforced Concrete (GFRC) Trim
Glass Fiber Reinforced Concrete (GFRC) is a high-strength composite material widely used in commercial and high-end residential applications. It is non-combustible, making it a strong choice for fire-rated applications. GFRC trim typically has a compressive strength of up to 12,000 psi and can be molded into intricate designs to replicate cast stone or masonry.
Common applications include:
-
Historic restoration projects
-
Large architectural panels and facades
-
Fire-rated exterior trim for commercial buildings
It’s significantly heavier than other trim options, requiring additional structural support and increasing installation complexity. Despite this drawback, GFRC is commonly specified for historic restorations and large commercial buildings requiring durability and aesthetic appeal.
Molded Limestone Trim
Molded limestone trim replicates the look of natural limestone while reducing weight and cost. This material is often used in classical and historic architecture, providing a high-end appearance with improved workability compared to quarried stone. Molded limestone is durable, weather-resistant, and can be customized to match existing stonework.
You’ll see molded limestone in:
-
Window and door surrounds
-
Decorative keystones and pilasters
-
Cornices and custom façade elements
Molded Polyurethane Trim
Molded polyurethane trim is a lightweight and versatile material best suited for decorative elements. It’s also resistant to moisture and insects, making it a low-maintenance option. With a screw withdrawal strength of 143 lbs and a structural load capacity of up to 225 psf, it is durable but not intended for load-bearing applications. Custom designs can be more challenging, as polyurethane trim requires molds to be created, limiting its flexibility for one-off applications. In those instances, cellular PVC might be a more affordable option.
Molded polyurethane is often used for:
-
Ornamental trim and brackets
-
Custom-designed moldings and corbels
-
Replicated historic details for restoration projects
Aluminum Trim
Aluminum trim is gaining popularity in exterior applications, particularly in modern and industrial-style designs. It’s corrosion-resistant, lightweight, and available with factory-applied powder coatings for long-term durability. Aluminum isn’t often used for traditional trim applications due to its lack of texture and warmth compared to wood-based materials. It’s best suited for contemporary facades, pergolas, trellises, and shade structures with a sleek, modern aesthetic.
Comparing Materials: Choosing the Right Option
Best for Traditional or Custom Designs: Wood, Cellular PVC, Fiberglass
Best for High-Moisture or Coastal Areas: Cellular PVC, Polyurethane , Fiberglass
Most Budget-Friendly: Fiber Cement, Engineered Wood, Polyurethane
Most Durable & Low Maintenance: Fiberglass, GFRC, Cellular PVC
Which is Best for Your Project?
Exterior trim is essential to a structure's longevity and overall esthetic. Whether prioritizing cost, durability, or aesthetic appeal, selecting the right material ensures long-term performance. Builders and architects should evaluate project needs carefully to determine the best fit, leveraging advancements in material technology for both function and style. Which material is right for your project? Contact us today, and we’ll be happy to help you find the perfect fit.