One of my saddest experiences as a contractor occurred when I revisited a gorgeous wood deck I had built 10 years before. It was a wreck. The homeowner had tried to keep up with the maintenance, but he'd found that it was too much work. He had discovered, like so many other wooden-deck owners, that even when it doesn't rot, wood tends to crack, splinter and warp.
Fortunately, a whole range of new deck and railing materials have been developed in recent years that last longer than wood and need little maintenance. Although still more expensive than standard treated wood, composite woods—and other maintenance-free materials like vinyl and aluminum—are getting popular fast.
In this article, we'll walk you through the variety of materials now available for low-maintenance deck railings and tell you their strengths and weaknesses. While many are by the same manufacturers that make decking, they're a separate product. You can use them on any type of deck, including decks made of wood.
Figure A: Low-Maintenance Railing Materials
Hollow posts; hollow railing and balusters; usually surface bolted to deck; special assembly system.
Vinyl and plastics
Hollow posts; railing and balusters hollow and usually steel reinforced; 4x4 wood posts sometimes required; special assembly system.
Hollow posts; railings and balusters hollow; 4x4 wood posts required; special assembly system.
Hollow posts; railings and balusters either solid or hollow; 4x4 wood posts often required; special assembly system.
Solid posts; railings and balusters either solid or hollow; often installed like solid wood.
The post sections shown in Figure A illustrate the range of materials now used for railings. The composites are the most popular, as is composite decking. They're made from a blend of wood fibers and either virgin or recycled plastic, mixed into a paste and then extruded into the various railing shapes. The fibers provide strength and stability while the plastic protects the fibers from moisture, rot and insects.
Most lumberyards and home centers now stock at least one or two brands and will special-order others. Each brand has a slightly different design, selection of colors and sometimes texture. Some are hollow and some are solid. Each system comes with its own assembly directions, which must be followed to ensure strength and safety.
Solid types are more like solid wood; you bolt the posts to the deck framing just as with wood 4x4s. Since the color is consistent throughout the material, you can shape or bevel edges with a router and leave post ends exposed. And since the material is solid, it's more resistant to dings and nicks. On the downside, solid composites are heavier, and if you don't support them properly, they'll sag. And you won't find them with PVC coatings.
Hollow composites are lighter and slightly stiffer. Rails and balusters are usually connected with special brackets, which are hidden (Figure B). They allow you to make strong connections easier and faster.
You can also slide the hollow posts in most systems right over standard 4x4 wood deck posts. In fact, some hollow systems require 4x4 wood posts for strength. On the downside, hollow posts tend to be larger than solid types. They often require special trim pieces to cover joints and edges. Curves aren't an option as they are with solid railings.
Most composites are paintable, but eventually the paint will age and you'll have to repaint, increasing the maintenance factor.
Tips for Installing Composite Railings
If you've worked with wood, you won't have any trouble working with composites. Each system is engineered to meet the requirements of the building code, so it's important not to deviate from those instructions. Composites (as well as PVC and plastics) also need extra space for expansion in hot weather. The instructions will specify how much, or the fastening system will account for this factor. Composites are not meant for ground contact.
Keep in mind that composites can't be used for structural purposes. And although they're heavier and denser than wood, they're neither as strong nor as stiff. They can break if dropped or bent too far. If you skimp on supports, composites will sag from their own weight. On the plus side, this means that some types will bend easily or can be heated and forced into attractive permanent curves.
And finally, be aware that some systems have limitations and not all have been tested and approved to meet the building code. Always check this detail with the manufacturer and with your local building officials.
Several companies make solid-plastic decking and handrail systems that look like composites. You install them similar to hollow composites. They're slightly more expensive, but the manufacturers claim that solid plastic is more durable and long lasting.
If you want a white railing, vinyl railings can be a good choice. You'll find a wide price range. The more expensive varieties are long lasting and tough and have well-engineered metal inserts for stiffness and strength. Vinyl doesn't stain or collect mold as easily as composites in most situations, and its smooth surface is easy to clean.
On the downside, all the parts are hollow, so vinyl railings usually require more pieces for strength. You slip the vinyl posts over either a sturdy metal base or a wood 4x4 bolted to the deck frame.
All-aluminum railing systems are made by many companies, usually for apartment and commercial buildings. They're slimmer and a bit commercial looking, but they're extremely long lasting. Since they are usually surface mounted, they require especially strong anchoring systems.
Low-maintenance balusters made from metal or glass and designed to be used with wood (or solid composites) are also available. They're available through home centers and lumberyards or can be ordered online.