Windows play a crucial role in enhancing the aesthetic appeal of a home, and the exterior window trim is an essential component that not only complements the architectural design but also provides protection against the elements. Choosing the right material for your wood exterior window trim is paramount for achieving long-lasting results.
Wood Exterior Window Trim Materials
Real Wood
Historically and conventionally, authentic wood has been the preferred material for exterior window trim.
The utilization of real wood for exterior trim has often been met with scepticism, and at times, rightfully so. Many wood varieties struggle to withstand the harsh conditions imposed by weather and prolonged exposure to sunlight.
In previous instances, issues such as inadequate paint adhesion, rot, mildew, surface cracks, warping, and decay have significantly impacted the durability of real wood, even when treated with primer paint.
Certain manufacturers opt to treat raw wood with primer paint, commonly referred to as Primed White Wood (PWW). Alternatively, some manufacturers incorporate preservatives into their primer paint to address specific concerns. However, it’s important to note that not all manufacturers adhere to optimal practices.
Despite these challenges, there are compelling reasons why wood remains the optimal choice. Let’s explore the two available options within the realm of authentic wood.
Cedar
Cedar is another popular choice for wood exterior window trim. It boasts natural oils that act as a deterrent to insects and decay, making it a suitable material for outdoor applications. Cedar's lightweight nature also makes it easier to work with during installation.
Cedar stands out as a superb material for exterior embellishments. Its versatility is evident in a range of applications, spanning from cedar shakes to porch posts, siding, trim, and fascia. The inherent qualities of cedar, such as resistance to rot, mould, and mildew, coupled with its relatively lightweight nature, make it an attractive choice.
Natural cedar exhibits ample strength, allowing for structural applications, and its easy installation is facilitated by its availability in various sizes.
Opting for cedar as a window trim is a prudent decision, considering its inherent durability and reliability. Nevertheless, it is worth noting that cedar ranks as the most expensive window trim option in today’s market, typically lacking the inclusion of a warranty.
While ideal for those unconstrained by construction costs, the majority of us may find ourselves exploring alternative options due to the considerable price difference, leading to a somewhat startling realization when comparing the available choices.
Non-Wood Fascia for Exterior Window Trim
While wood exudes charm, modern alternatives offer durability and low maintenance, addressing some of the shortcomings associated with traditional wood trims.
OSB Based Products
Oriented Strand Board (OSB) based products provide a cost-effective alternative to real wood. These engineered wood products offer dimensional stability and resistance to warping and splitting. However, they may lack the natural aesthetics of real wood.
OSB-based products are commonly employed for window wrapping and demonstrate effective performance in this context approximately 90% of the time. Particularly suitable for use in dry climates, OSB boasts strength, cost-effectiveness, ease of cutting, and widespread availability. Its inherent resistance to rot, mildew, and decay is attributed to its resin content.
However, there are notable drawbacks. Exposure to water can lead to swelling in OSB, especially affecting cut ends, which may deform and fail to regain their original shape upon drying. The crux of the matter lies in the fact that when swelling occurs, it not only appears unsightly but also diminishes the overall aesthetic appeal of a home.
Another aspect where OSB falls short of window trim is in architectural styles that necessitate the extension of the top and bottom of the window trim beyond the side legs to achieve a classic craftsman look. Unless the top and bottom trim pieces can be mitred and seamlessly terminated into the ends of the legs, it results in a rough edge that does not lend itself well to paint application.
Consider the challenge of painting the edge of an OSB piece; the process proves to be impractical and yields unsatisfactory results.
Fiber Cement
Fibre cement is a composite material that combines cement, sand, and cellulose fibres. This blend results in a durable and weather-resistant material that can mimic the appearance of wood. Fibre cement requires minimal maintenance and is impervious to rot and pests.
Fibre cement addresses the drawbacks associated with OSB products, particularly by resisting swelling. The painted finish on the cut butt ends matches that of the front surface, providing a uniform appearance.
While fibre cement stands out as an excellent choice in damp and humid environments, it is essential to acknowledge certain issues associated with its use.
In dry and sunny climates, the prevalence of cracks is most notable on walls exposed extensively to sunlight. Considering the scarcity of areas in a house shielded from direct or indirect sunlight in arid regions, this becomes a notable concern.
The weight and brittleness of fibre cement pose challenges during installation, leading to fatigue for the installer. Its propensity to chip and break easily can contribute to increased costs, factoring in labour and breakage.
As houses naturally settle over time, fibre cement boards become susceptible to cracks, heightening the risk of water infiltration in the future.
A practical suggestion is to procure more fibre cement boards than initially planned, allowing for potential breakage during installation or handling, thereby ensuring a smoother and more cost-effective construction process.
FAQs
What to use for exterior window trim?
For exterior window trim, it’s common to use materials like wood, PVC, or composite materials. These options are chosen for their durability, resistance to weathering, and ability to complement the overall aesthetics of the home.
What is the wood trim above a window called?
The wood trim above a window is typically referred to as the “header” or “lintel.” It serves both functional and decorative purposes, providing structural support while adding visual appeal to the window.
What is the best wood trim for exterior windows?
Cedar and redwood are often considered among the best choices for exterior window trim. These woods are naturally resistant to decay and insects, making them durable options for withstanding outdoor elements.
What is the difference between exterior window casing and trim?
While the terms are sometimes used interchangeably, there’s a subtle difference between exterior window casing and trim. Casing usually refers to the moulding around the window frame, providing a finished look, while trim encompasses a broader range of elements, including casing, sills, and other decorative features that enhance the window’s appearance.
