PVC trim has long been a well-loved product by contractors and homeowners alike, especially in wet climates like ours. It’s easy to install, rot- and moisture-resistant, and impervious to insect damage, making it last many years before requiring replacement. Since PVC trim came on the market more than two decades ago, manufacturers have made significant improvements to their PVC products. Today, we’re learning about the next generation of PVC trim—AZEK PVC Trim with PaintPro® Technology.

Below you’ll find answers to some of the most frequently asked questions about PaintPro trim, supplied by an AZEK representative.

What is AZEK PVC Trim with PaintPro® Technology?

AZEK’s PaintPro product was engineered to address the challenges that go along with trying to maintain a proper finish on other materials like wood, fiber cement, and other trim materials. Essentially, the goal was to create one of the most low-maintenance paintable trim substrates on the market.

If you’ve ever applied paint to a piece of PVC, you’re familiar with the imperfect application (“beading” of color on the surface) and long cure time. PaintPro was developed to solve both of these problems. Not only does it easily accept paint, but also forms a superior bond between the paint and PVC surface, reducing the need for frequent repainting and eliminating any chance of cracking, warping, or chipping.

How is PVC different from other trim materials?

All building materials expand and contract; wood expands through the absorption of water, while PVC expands with changes in temperature (most commonly from heat from the sun). 

It’s virtually impossible to avoid water contact with most exterior wood trim installations—paint wears down over time allowing water to find its way in. This means that the only way to truly limit expansion and contraction is by diligently maintaining the paint finish. 

With PVC trim, while it expands and contracts lengthwise, you can minimize movement with proper installation and paint selection. Fastening close to the edges and applying adhesive at the joints will minimize expansion and contraction.

How does PaintPro Technology trim work?

PaintPro trim has the same moisture resistance and workability as regular PVC trim—it's designed to be handled the same as a piece of lumber. The biggest difference between PVC trim and PaintPro is more efficient paint application and superior paint adhesion. To start, the product has been specially treated in manufacturing to deliver a “primed” performance for superior paint application. With AZEK PaintPro Technology there is no need to sand or prime before you paint, saving time and labor on the job site. 

With regular PVC, once the paint has been brushed or sprayed on, the front side of the PVC paint will dry to the touch in less than an hour; however, the underside of the paint (which comes into contact with the PVC) can take up to 30 days to fully dry. That means you run the risk of smudging before it’s fully cured.

With PaintPro, paint dries to the touch 20-30 minutes after application and fully cures within 24 hours. 

What sizes does PaintPro trim come in?

PaintPro trim and siding come in both narrow board and sheet sizes, including sizes for board and batten siding. Although 4’ wide sheets are manufactured in eight-foot, 10’, 12’, 16’, and 20’ lengths, 16’ and 20’ sheets are currently not available in the Puget Sound region. PaintPro also comes in a square-edged corner board and one-piece skirt board.

What should I know before installing PVC trim?

AZEK recommends a number of installation best practices, summarized below:

  • The best time to install any kind of cellular PVC trim product is when it’s at its coldest (i.e., not in direct sunlight). Cellular PVC expands and contracts as temperature changes, so it’s at its smallest when it’s cold. 
  • Follow AZEK’s fastening recommendations: Fasten within 1” from the edge and ends of the board. For boards up to 8” wide, use 2 fasteners at the ends of the board and then 2 fasteners every 16” or less  (use three fasteners if boards are over 8” wide).
  • Use a PVC adhesive to glue joints together—this is a key step to eliminate the risk of joint separation. 
  • To fasten, it is recommended to use one of the following: the Cortex Fastening System, #8 stainless steel screws, or stainless steel coil siding nails. The Cortex Fastening system includes a plug manufactured using the same material as the trim; this eliminates the need to caulk, sand, and paint each nail hole.
  • Allow ⅛” of gap for every 18 feet of trim board; this accounts for any expansion/contraction due to temperature changes.
  • For more best practices, see AZEK’s installation basics.

What are the best practices for painting PVC trim?

When painting PVC trim products (regular or PaintPro), it’s important to follow AZEK’s paint type and color guidelines to ensure the best long-term performance. The first thing to know is that you should only ever use a paint that is made from 100 percent acrylic latex and approved for exterior use—this is a must.

When selecting a color, it’s important to pay attention to the Light Reflective Value (LRV) of the paint color in order to limit overheating. Each paint color has an assigned LRV, usually on the side of the can or available via the paint manufacturer’s website. This number specifies the total quantity of visible and usable light reflected by or absorbed into a surface. The LRV scale is numbered from zero to 100; zero is absolute black, 100 is absolute white.

If the color of paint you’re using falls on the light half of the scale (55 or above), you can use 100 percent acrylic latex exterior paint; if it falls on the dark half of the LRV scale (55 or below), you’ll need to use a paint specially formulated for PVC or vinyl application. Most major paint manufacturers make PVC-specific products. For absolute-black or custom-colored trim, AZEK recommends using a special paint called AquaSurTech. 

For more help with paint selection, we recommend consulting AZEK’s painting guidelines, where you can find recommended paint colors and manufacturers approved for use on their product.

PVC trim changed the way we thought about trim when it came onto the market 25 years ago; today, PaintPro trim is expanding its possibilities. To learn more about AZEK’s line of products, head to their website. For more information about PVC trim and siding, check out these tips for working with AZEK trim from master craftsman Daniel Westbrook.