Vi-Lux Cellular PVC Mouldings & Trim. Quality. Service. Value. The Reliable Choice.

Cellular PVC Trim & Moulding

Installation and maintenance

Installation Recommendations

The following guidelines are intended to help contractors and installers obtain the most professional and long-lasting results when working with Vi-Lux products. For details about the Vi-Lux product warranty, please click on warranty.


safetyObey all safe-work practices, including wearing safety boots, goggles and construction helmets. When cutting or sanding product, wear a mask to avoid inhaling dust. Ensure adequate ventilation when gluing, caulking or painting. Follow all manufacturer’s recommendations and warnings.

Product storage

product storageVi-Lux products are more flexible than wood, so it may conform to uneven surfaces, particularly in warm weather. Store Vi-Lux mouldings up off the ground on a flat, level surface. Product stored outside should be covered to keep the product clean. If it does get dirty, clean after installation. Vi-Lux mouldings should be stored away from direct sunlight and high temperatures.

Cutting, Bonding and Fastening


cuttingVi-Lux mouldings can be cut using standard woodworking power tools. Keep blades sharp for best results. If clamping when cutting, use blocks to avoid marking the products. Best results are obtained using saw blades designed for cutting wood or plastic. A 32-tooth carbide-tipped blade is recommended with circular saws. To maintain a smooth edge, support the trim across its entire length when you cut it.

AVOID rapid sawing or fine-tooth blades to reduce heat build-up.


You can drill Vi-Lux mouldings with standard woodworking drill bits. Do not use bits made for rigid PVC. Avoid heat buildup from excessive friction, and remove the shavings from the drill hole frequently.


For crisp, clean edges, use a carbide-tipped bit on a router.


bondingGluing Vi-Lux mouldings to Vi-Lux mouldings or other PVC: Never use adhesives alone to fasten Vi-Lux mouldings to a substrate. However, to bond joints such as corners, window surrounds, and long fascia runs, use products such as Gorilla PVC™ or Bond & Fill®.

The amount of gap required depends on various factors; the length of piece being installed, the overall range of temperatures experienced over the year, exposure to the sun, and the temperature at the time of installation. When installing longer pieces in cold weather (25 to 55°F), leave a gap of about 1/8” per 12’ length. (For shorter pieces the gap can be less). In warmer weather (75°F or over), do not leave a gap, providing the product is warm when applied.

Seal Joints and Gaps:
To prevent joint separation, fill all joints (whether butted tight or with a gap) with a urethane acrylic sealant (which expands and contracts at the same rate as the product). Two recommended products are Pro-Series Quad Window, Siding, Gutter & Roof Sealant from OSI (, and Bond & Fill Structural Adhesive & Filler ( When sealing a butt joint, apply sealant only to one butt end, and apply to the front half of the butt end only, so the sealant can expand back into the joint. Ensure good contact between the sealant and the two butt ends. Touch up irregular areas with additional sealant, and tool normally.

butted and mitered jointsEnsure all surfaces to be glued are smooth and clean. Use exterior-grade, PVC compatible, urethane-based adhesives. Two recommended products are Pro-Series Quad Window, Siding, Gutter & Roof Sealant from OSI (, and Bond & Fill Structural Adhesive & Filler ( When fastening to PVC substrates, use white PVC gutter cement; note that PVC gutter cement tends to turn yellow over time outdoors, so it should not be used in visible applications. AVOID using silicone-based adhesives. Clamping or other mechanical fastening is recommended to hold product in place while adhesive cures. For all adhesives, follow the adhesive manufacturer’s recommendations.

Bonding to other surfaces:
Vi-Lux mouldings can also be bonded to a variety of substrates. Specific substrate combinations require specific adhesives: contact cement, epoxy, rubber-based adhesives, or urethane-based adhesives. Ensure to use appropriate cement for each substrate. Always follow the adhesive manufacturer’s instructions, and check the bond on a test piece before proceeding with the installation.


fasteningFor longer lengths of product, begin at one end and work to other end or at middle and fasten outwards. NEVER fasten from both ends toward the middle, which can create stress and expansion problems. Fasten at 16” intervals along the length, and keep nails and screws at least 5/16” from ends and edges to avoid splitting. Fastener heads should be flush with the surface of the trim or slightly indented and no closer than ¾” from the end of the board.

  • Nails: Use corrosion-resistant, smooth-shank, screw, annular-threaded or spiral type nails, at least 6d in size (shank diameter of 0.090”), and long enough to penetrate substrate by at least 1.5”. AVOID large-head nails and ring-shank nails due to excessive heat during fastening. When installing, nail flush to avoid the need for finishing holes. In cold weather (below 32°F), pre-drilling is recommended to avoid cracking. If using a power air nailer, adjust the length of stroke (not the air pressure) to control nail depth.
  • Screws: Use standard, flat-head, stainless steel wood screws, at least #6, long enough to penetrate substrate by at least 1”. Use drill bits designed for wood or metal. Slightly countersink screws and finish holes.

Window and Door Trim

Cladding and trim are not meant to be watertight barriers. Before you install any cladding materials or trim, flash all openings so that they shed water to exterior of the cladding and trim materials. window and door trim

  1. Install flashing along the bottom of the opening. The width of the flashing must extend beyond the width of the trim being installed. Be sure the bottom flashing is long enough to direct water over the cladding material.
  2. Install flashing along each side of the opening. Be sure to overlap the bottom flashing. The width of the flashing must extend beyond the width of the trim being installed.
  3. Install the top flashing by overlapping the tops of the side flashing.
  4. To install the trim, miter the joints and use a PVC adhesive to adhere the joints. Fasten the trim to the substrate on both sides of the miter. Use at least two fasteners per board.
  5. For best results, create a scarf joint by cutting a taper on the end of the trim pieces. Gluing the joints between the trim pieces will help eliminate separation caused by expansion and contraction. Place fasteners either through the scarf joint or on both sides of the scarf joint. This will help minimize expansion and contraction.


bendingVi-Lux mouldings can be easily bent to accommodate curved applications. Convection air-circulating ovens, strip heaters or radiant heaters can be used. Apply heat evenly to both sides until product is flexible. Oven times will vary depending on the size and density of the profile.

To bend Vi-Lux mouldings:

  1. Control the temperature of the surface and the amount of time the material is heated – the surface temperature should not exceed 300°F for more than 10 minutes.
  2. To guarantee uniformity, gradually increase the temperature and heat both sides of the material simultaneously.
  3. In general, heating time is about 3 minutes for each ¼” of thickness of material. When the trim’s shape is irregular or the heat is not uniform, heating times may be longer. Heating times will also differ depending on oven design.
  4. Apply the heat evenly until the trim becomes flexible and easy to form.
  5. Take care not to overheat the material, as overheating can produce a rough texture and discoloration.
  6. When you bend textured cellular PVC, the wood grain may distort depending on the radius of the bend.
  7. Once the moulding/trim is heated, remove and put into a fixture or a jig to hold the finished shape while cooling is taking place. Cooling can be accomplished with fans or compressed air.

Take care when handling heated materials, as hot PVC can produce severe burns. Wear protective gloves that are thick enough to avoid burns.

Expansion and Contraction

Cellular PVC may expand or contract due to changes in temperature. You should allow for this movement when fastening Vi-Lux mouldings. You can minimize the movement of PVC trim by observing proper fastening techniques along the entire length of the trim.

  • Allow 1/8” per 12’ length of product for expansion and contraction (1/16” at each end).
  • Scarf joints work well to minimize seams and allow expansion and contraction.
  • Gluing the joints (such as butt joints) will help eliminate separation caused by expansion and contraction.

Finishing and painting

paintingVi-Lux exterior mouldings come with factory applied VI-GUARD® coating in natural white and do not require painting for protection. If you want to paint it a custom colour, follow these important guidelines:

  • As with any surface to be painted, the trim must be clean, dry and free of chalk, grease, oil, dirt and mold or mildew.
  • Apply a 100% acrylic latex paint with an LRV (light reflecting value) of 55 units or higher. (Generally, the higher the LRV, the lighter the colour. The LRV of a particular colour should be listed next to the colour on your paint dealer’s colour chart).
  • For paint colours with an LRV of 54 or lower, you must use a paint that has been specifically developed for application on PVC. Sherwin-Williams VinylSafe Color Technology is available in their SuperPaint Exterior and Duration coatings.
  • In every case, follow the paint manufacturer’s recommendations for use and application of the paint.
  • Due to the extended cure times of paint applied to PVC cellular trim, we recommend installing Vi-Lux mouldings first and then painting it unless the trim is painted in a professional prefinishing operation and allowed to cure completely.

Tips on Painting

  • To obtain adequate paint adhesion, be sure the surface of the Vi-Lux Trimboard is clean, dry and free of dirt, loose or peeling paint, mildew, chalk, grease and any other surface contaminants before applying paint. Use a mild detergent (Spic and Span®) and water or denatured alcohol for cleaning.
  • Paint can take up to 30 days to fully cure depending on outside temperatures and humidity conditions.
  • Follow the pain manufacturer’s surface preparation and application recommendations.
  • If you paint Vi-Lux a dark color you must first remove it before applying a lighter color paint with an LRV of 55 units or greater.

AVOID using dark colors of paint (which can lead to increased product expansion due to heat gain), which voids the Vi-Lux warranty. If dark paints are used, use a paint that has been specifically developed for application on PVC such as Sherwin-Williams Vinyl Safe Color Technology paints. AVOID stains, oils/alkyd paints and primers or vinyl-based paints.

Examples of Unacceptable Paint Colors: Less than 55 LRV Units

Pay attention to light reflective values (LRV) when painting Vi-Lux mouldings and trim.

Less than 55 Units
Less than 55 Units LRV

Examples of Acceptable Paint Colors: Greater than 55 LRV Units

Pay attention to light reflective values (LRV) when painting Vi-Lux mouldings and trim.

More than 55 Units
Less than 55 Units LRV

Cleaning and maintenance

Vi-Lux mouldings can usually be cleaned with a hose, brush and an ordinary detergent, household cleaner or glass cleaner such as Windex or Fantastic All-Purpose. For scratches, gently sand out with very fine sandpaper (at least 220 grit), then fill with caulking or filler.

AVOID using acetone, paint remover or lacquer thinner; as well as harsh cleaners containing glycol ethers or ethanol-type solvents, which will damage the PVC surface if left on for several minutes.