Installing PVC trim outside involves several key steps, from preparing the boards to fastening them and finishing the joints and holes. Following proper techniques ensures a durable and aesthetically pleasing result.
Here is a guide based on common practices and the referenced installation steps.
Preparing Your PVC Trim Boards
Proper preparation is essential for a smooth installation and optimal appearance.
Cutting PVC Trim Boards
- Tools: Use sharp carbide-tipped blades specifically designed for PVC or wood. A chop saw or circular saw is typically used for straight cuts, while a jigsaw or coping saw can be used for intricate shapes.
- Technique: Cut slowly and steadily to prevent melting or chipping the material. Support the trim board well to avoid vibration, which can lead to poor cuts.
Routing
- Purpose: Routing allows you to create decorative edges or specific profiles on the PVC trim board.
- Tools: Use standard woodworking routers and bits.
- Technique: Make multiple shallow passes rather than one deep cut to achieve a clean profile and prevent overheating the material.
Assembly and Attachment
Once the individual pieces are prepared, the next steps involve assembling sections and attaching them to the structure.
Pre-assembling PVC Trim
- Benefit: Assembling trim sections on the ground, like corner boards or complex window surrounds, can make installation easier and more accurate.
- Method: Use appropriate adhesives and/or fasteners designed for PVC to join pieces before lifting them into place.
Drilling
- Purpose: Drilling might be necessary for pilot holes when using certain fasteners or for creating openings for wires or pipes passing through the trim.
- Tools: Use standard drill bits.
- Technique: Drill at a moderate speed to avoid melting the PVC.
Fastening Your PVC Trim Boards
- Fasteners: Use fasteners specifically recommended for PVC trim and exterior use. Stainless steel or hot-dipped galvanized fasteners are crucial to prevent corrosion bleed-through which can stain the white trim. Examples include:
- Trim screws (often self-tapping)
- Finish nails (driven with a nail gun or by hand)
- Technique: Fasten the trim securely according to the manufacturer's guidelines. Avoid over-driving fasteners, which can dimple or crack the PVC. Fasteners should typically be placed every 12-16 inches and appropriately spaced from edges.
Gluing PVC Trim Boards
- Application: Gluing can be used in conjunction with fasteners, particularly for wider trim applications or where mechanical fasteners need extra support.
- Adhesive: Use a high-quality exterior-grade adhesive compatible with PVC.
- Technique: Apply adhesive following the product instructions, ensuring good contact between the trim and the substrate.
Joining and Finishing
The final steps involve connecting pieces seamlessly and concealing fasteners for a clean look.
Cementing PVC Trim Board Joints Together
- Purpose: For strong, weather-tight joints, especially at butt joints or corner connections.
- Product: Use a specific PVC trim cement (sometimes called solvent cement).
- Technique: Apply cement generously to both surfaces being joined. The cement chemically welds the two pieces together. Wipe away excess immediately. Use clamps or tape to hold joints together while the cement sets. This creates a virtually seamless joint that won't open with temperature changes.
Filling Fastener Holes
- Purpose: To hide the heads of fasteners and create a smooth surface.
- Filler: Use a high-quality exterior-grade PVC patching compound or filler.
- Technique: Apply the filler according to product instructions, typically pushing it firmly into the hole. Once cured, sand smooth. Ensure the filler is paintable if you plan to paint the trim.
By following these steps, you can successfully install durable and low-maintenance PVC trim on the exterior of a building.
