After decades of cobbling together deck railings from various pieces of pressure-treated lumber — often to ill effect — carpenters now have new options. Following on the development of composite and plastic decking, manufacturers are offering kits that can speed installation and provide a clean, professional-looking railing that doesn’t need painting or staining. For this article, I looked at wood-plastic composite and vinyl railings, as well as a few aluminum systems.
The railing kits include top and bottom rails, balusters, and installation hardware. Screws and hardware are usually made from stainless steel and, if exposed, are powder-coated to match the rails. Post sleeves, caps, and post trims are typically purchased separately. Special hardware — usually hinged brackets that you pivot to the proper angle — is available for angled layouts and stair rails.
Manufacturers offer a variety of styles and colors to match or complement most types of decking. Products can be customized by using different types of balusters or mixing colors.
While manufactured rails promise easy installation — the post sleeves require no assembly, the balusters are precut, and all the connections have been worked out in advance — there are a couple of key points to keep in mind.
First, baluster spacing is fixed, because the top and bottom rails come with predrilled holes for fastening balusters. This is a great time-saver, but it means there’s no good way to fudge the spacing when balusters crowd the posts. The instructions typically say to lay out rail cuts from the middle — usually the center of a space — in order to create equal end spaces. Check before you cut; you might be able to gain space by shifting the layout and using one less baluster. You’ll get the best results if you can lay out your posts to match the railing, but this isn’t always possible.
Second, while many manufacturers offer rugged post mounts for attaching to stone or concrete slabs, most railing kits installed in residential settings rely on 4x4 posts for their structural integrity. This means that the builder assumes responsibility for giving the customer a safe, code-compliant railing. Fortunately, researchers and manufacturers have addressed this issue and there are now several hardware options available that provide a straightforward solution (more on that to come).
Wood-Plastic Composite Railings
Composite railings are made from the same kinds of formulations used in composite decking. First-generation railing products were made from a single layer of composite. More recently, manufacturers have begun using co-extruded material.
Single-layer railing products have the look and feel of composite decking; typically heavier and more flexible than wood, they’re often waxy and mottled in appearance. Composites contain a mix of wood flour (finely ground sawdust) and a polymer such as polyethylene or polypropylene. The polymer binds the material together; the wood fiber is an inexpensive filler that increases strength and thermal stability.
The most basic type of composite railing is made from a single layer of the same material used to make composite decking.
Pieces are heavy and waxy and look slightly grainy — the plastic equivalent of MDF or particle board.
Parts are produced by extrusion. Manufacturers take pains to ensure that the fiber is fully encapsulated within the polymer so that the composite is resistant to insects, rot, and mold. Inevitably, though, some of the fiber remains at or near the surface, where sun and rain can get to it. Past failures of composite decking were often the result of fiber getting wet. In extreme cases, the material cracked, swelled, or deteriorated; more typically, the partially exposed fibers became stained or supported the growth of mold. Most composites now contain biocides to suppress the growth of rot and mold.
Discoloration from the sun is also a problem. Manufacturers add pigment and UV stabilizers to the mix, but fading is usually excluded from warranty coverage.
Co-extruded composites. Some newer composite railings are co-extruded, meaning that a thin cap layer of vinyl (or acrylic) is bonded to the composite core. Co-extruded composites are more resistant to mold and fading because there’s no wood fiber in the cap. The cores are typically a wood-vinyl mix, which bonds well to the vinyl cap and is also lighter and stiffer than a conventional composite. The cap layers are fairly tough: In researching this article, I scraped co-extruded parts from several manufacturers with the tip of a screwdriver. It was hard getting through to the core — much harder than scraping through paint on wood. The resulting scratches looked bad but posed no danger to the composite below.
Co-extruded railings are available in standard colors like white, tan, brown, and gray, as well as in black, which is currently quite popular. The cap layer can be textured to look like painted wood, though the finish is typically glossier. Azek’s Premier Rail and GAF’s RailWays are among the more convincing lookalikes, resembling wood that’s been sprayed and then back-rolled. Radiance Rail (TimberTech) and Horizon Plus (Fiberon) are also fairly convincing, though their balusters are a bit too smooth. At the other end of the spectrum are products such as CertainTeed’s Panorama, which is far too smooth to be mistaken for wood.
Co-extruded material has a wood-vinyl composite capped by a thin layer of vinyl.
The mottled appearance of the single-layer composite at far left is due to the presence of partially exposed wood fiber; the cap layer of the co-extruded material to its right contains no fiber.
The cap layer on the GAF RailWays product has the texture of wood that’s been painted and back-rolled.
Installation of composites. Composite rails are easy to install. The carpenter slides the post covers over the 4x4 support posts, cuts the rails to length, then assembles the balustrade. In most cases, the balusters attach with screws driven through predrilled holes in the subrails. Once assembled, the balustrade is positioned between the posts, fastened in place, and covered with a top rail. While screwing in balusters is not the fastest method of assembly, it’s certainly the most bullet-proof, providing little opportunity for joints to open or balusters to rattle. Some manufacturers have devised methods to speed the installation of balusters by omitting the screws.
Like many composite products, the Azek Premier Rail system is installed by sliding a post sleeve over a wood support post.
Screwing balusters to a subrail.
Covering the subrail with a top rail.
Then securing the rails to posts.
The hollow balusters in GAF’s RailWays system fit over ribbed plastic fittings screwed to the rail before assembly.
Fiberon’s Horizon Plus Railing relies on press-fit plastic inserts — one end fits in the baluster and the other in a slot in the rail.
The balusters in Trex’s Artisan Series drop into routed openings in a vinyl spacer strip; it snaps into the rail.
Rails are typically joined to posts with stainless-steel fasteners and L-shaped metal brackets that butt to the post and the bottom of the rail. While color-matched powder-coated brackets are fairly inconspicuous, a cleaner look is achieved with a two-piece rail that completely conceals the hardware, as with CertainTeed’s Panorama, TimberTech’s Radiance, and Trex’s Artisan series.
While the powder-coated hardware on this Azek rail is fairly unobtrusive, the bracket on the TimberTech Radiance rail.
The completely concealed by the top rail.
Vinyl rails consist of hollow vinyl sleeves over structural metal channels. The metal, usually an aluminum extrusion, supports the sleeve, which by itself is not stiff enough for long spans. Because balusters are subject to less stress than rails, they can be made from vinyl alone. Dark vinyl tends to fade, so only light colors are available — white, tan, brown, and gray.
Though vinyl railings are intended to resemble painted wood, the effect is not convincing. The smooth, shiny surface is a giveaway, as are the plastic brackets that vinyl systems typically rely on to conceal the connections between posts and rails.
Vinyl rail extrusions are reinforced with aluminum channel.
In most vinyl kits, an obvious plastic bracket covers the joint between post and rail.
Most companies buy vinyl extrusions from large manufacturers like Veka or Kroy, then combine the parts in various ways to produce individualized products. It’s not unusual to see the same parts across several brands.
Installing vinyl rails. Vinyl systems are very easy to install because the balusters drop into holes in the rails. (The drawback is that because they’re not screwed into place, the balusters could rattle in the wind or squeak when someone leans on the rail.) The railing cuts aren’t critical because the connection is hidden by the plastic bracket.
With the lower rail of the Veka VI Pro system in place and the balusters in their holes.
All that’s left to do is fit the upper ends of the balusters into the top rail. The VI Pro uses heavy aluminum hardware.
Plastic hardware — as on the CertainTeed Panorama rail — is more typical for vinyl railings.
Noteworthy products. CertainTeed makes a couple of vinyl products that — when viewed from a distance — might almost pass for wood. The company’s Edgewood series rails are colored and textured to resemble wood brushed with paint or stain. If it weren’t for the plastic brackets, they’d be fairly convincing. And its Colonial vinyl baluster, which is supposed to look like a turned wood spindle, is thicker-walled than most and crisp enough to be believable.
Veka’s VI Pro Handrail System comes with the usual square balusters or can be routed to accept round 3/4-inch steel pickets in a variety of patterns and finishes. Curved railings are available in stock and custom radii. The beefy aluminum connectors for the VI Pro rail are more substantial and contain more screws than the plastic connectors normally used with vinyl rail.