Cellular PVC is a durable, low-maintenance building material commonly used for exterior trim. It’s made from polyvinyl chloride with a unique internal structure that gives it the strength and versatility of wood while resisting moisture, rot, and insects.
Thanks to its clean, polished appearance and ability to be shaped and milled like wood, cellular PVC is a favorite among builders and architects working on high-end homes and commercial projects. It offers the timeless look of traditional trim without the upkeep, making it ideal for applications where quality and longevity matter.
What is cellular PVC?
Cellular PVC is an expanded form of standard polyvinyl chloride that includes tiny air pockets, giving it a lightweight yet strong structure. It’s solid throughout, but unlike rigid PVC pipe, it can be cut, nailed, routed, and milled with ordinary woodworking tools.
This makes it an excellent replacement for wood in trim, fascia, soffits, columns, window surrounds, decorative moldings, pergolas, and more. It’s smooth, paintable, and doesn’t absorb water, which makes it especially well-suited for exterior applications.
Why Builders Use Cellular PVC Trim
Cellular PVC trim is engineered to solve the problems that come with natural wood. It doesn’t rot, swell, crack, or split when exposed to moisture, and it won’t attract insects. It’s also resistant to mold and mildew, making it ideal for humid climates and ground-contact applications.
Because of its versatility, it’s commonly used in both modern and historic applications, including:
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Window and door surrounds
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Decorative brackets and cornices
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Column wraps and entablatures
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Pergolas and trellises
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Railing and balustrade systems
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Custom and curved millwork
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Replication of traditional architectural elements
The material is also flame retardant and nonporous, making it safe and hygienic for exterior use.
Does PVC trim expand and contract?
Yes, like all plastic-based materials, cellular PVC expands and contracts with changes in temperature. This is a normal part of its behavior and should be accounted for during installation. Builders must use proper spacing, fastening, and adhesive techniques to ensure long-term stability and prevent buckling or gaps.
If you plan to paint your trim, especially in a darker color, it’s essential to consider how heat will affect the material. That brings us to one of the most common questions about cellular PVC.
Can you paint PVC trim?
Yes, you can paint PVC trim—and in fact, we recommend it. While cellular PVC comes pre-finished in white, painting it can help seal any cut or milled edges, reduce dirt and mildew buildup, and keep it looking clean longer.
If you’re choosing a lighter color (with an LRV of 57 or higher), standard 100% acrylic latex paint works well. For darker shades, it’s important to use a solar-reflective paint that minimizes heat absorption and reduces the risk of thermal movement.
Is cellular PVC right for your project?
If you’re looking for a trim material that balances performance, longevity, and aesthetics, cellular PVC is hard to beat. It offers the workability of wood with none of the maintenance headaches, and it performs exceptionally well in environments where moisture and weather exposure are a concern.
Whether you’re designing for a coastal home, a high-end commercial building, or a restoration project, cellular PVC is a wise choice that combines modern engineering with classic appeal.
Have questions or want to explore trim options for your next build? We’d love to have a conversation about your options.