Decking – Wood, Composites and Synthetics
Taking the confusion out of modern decking materials

Well over 15 years ago, the decking market was brought out of the stone ages of lumber being the only choice for decking material with the invention of composite decking material. This rather simple concept has paved the way for many startup decking manufactures as well as seasoned decking manufacturers to modernize and diversify their product lines by, what was considered at the time, the latest fad. Time and use of these new products have proven them not a passing fad, but a brilliant use of modern and old school technologies to build a better mouse trap.

First, let’s examine what a composite is. The word composite means, a blend or mixture of two or more materials or substances to create a new material. The reasons for seeking a composite was two fold; First, to create a material that would not crack, warp or require constant maintenance and second, a material less affected by the wood market and it’s up and down roller coaster pricing as a commodity. An additional benefit was discovered along the way that would utilize the enormous amount of recyclable plastics that were clogging up our landfills. The concept has seen enormous competition and growth because once one new composite decking product was on the market, everyone wanted in on this promising new technology.

Some manufacturers were more successful than others at producing a better product. With nothing more than a Google search on “decking litigation” you can see who has been accused of not doing such good job. Understand that there have been a lot of materials to come and go. Some composites have worked, while others have failed. The first composites on the market all worked pretty much the same. The manufactures attempted to make a composite board using a mixture of plastic and wood chips, or wood that was ground into a powder or flax seed casings. Basically, they all had the idea to blend plastics with an organic filler. Why did they use organic fillers? Primarily because, if the entire board was made of plastic it would not have enough strength to span the typical distance between decking stringers. It would in effect bend downward as weight was applied to it. This bending under a load is called deflection. All building products have some degree of deflection, so achieving the acceptable amount of deflection is the goal. If the manufacturers could stiffen the plastic with other additives, they could meet the allowable deflection amounts and be accepted as viable option by the building industry. In these early cases, they used all or some of the organic materials listed above, blended it, and “Shazam”, the birth of an industry.

What are the pros? Well, with a wood or organic filled composite, you get a product without wood grain (growth pattern) that will split or crack as wood deck boards will. You can also buy a composite that is colored to resemble just about any kind of wood without the expense of costly exotic wood. Also for just about double the price of standard lumber you can have a product that has a warranty and doesn’t give the kids splinters.
Sounds good, doesn’t it? Well not so fast. For all of the pros that composites have, the fact remains that there are still some major concerns. First of all, a wood filled composite will, in almost every case, absorb water. Why should you care? Well, let’s take a piece of wood and saturate it with water, encase the wood in plastic and then expose it to the immense summer heat. What happens? You guessed it, mold and mildew. After all, organic material is made to naturally decompose and this process results in rot and decay. Also the manufacturers use resins and glues to get all that stuff to stick together. Therefore, it is almost impossible to find a color that doesn’t have a pretty dramatic rate of fade. Many manufactures also have problems with cracking and splitting as the product weathers and most have to be pre-drilled upon installation which drives the cost of labor up. So as you see there are things you give up for the advantages of a wood filled composite.

I think we would all agree that these modern composites are a step in the right direction from the once a year pressure washing, sanding and staining of standard decking lumber but isn’t their something better? I mean, we can put a man on the moon, delve into the ocean depths and clone a sheep but we can’t figure this out…… Yes, we can and it is called Synthetics.

Synthetic decking material has been used for years but not until recently have prices come down and the quality of recycled materials gone up to the conclusion of a competitive over the counter price. Now synthetic decking is well within the budget of most consumers and have far better warranties and a much higher performance standard than regular wood filled composites. With that said, let’s look at a couple of different synthetics. The synthetic market is primarily made up of two products; The first is a 100% virgin material PVC (polyvinyl chloride) and the second, a mostly recycled product utilizing HDPE (high-density polyethylene). There have been many advances in both of these products, and they each have there own individual features. HDPE and PVC both share the same advantages over wood and wood filled composites, which is, they do not use any material inside the board that can rot, mold or mildew. This means the splitting, cracking, splintering and mold and mildew growth do not occur. Both of these synthetic examples do not absorb moisture, because they are what is called a “closed molecular structure plastic”. This means they can not absorb moisture because the pores of the plastics are closed. Also these products are much more color stable than wood or wood composites because they are manufactured using dyes that are specifically designed and engineered for the plastic not all the wood, glue, resins and plastics contained in a wood filled composite. With all of these advantages at the same price point as your better rated wood filled composite, Synthetic decking products is the smartest choice for an educated consumer.

Which synthetic decking material is right for you? That is a questions that I can not answer, but here are a few points that can help you in your choice. First of all, PVC is a product that most of us are already comfortable with. You can look at your neighbor’s fence or your PVC lattice work in the garden or even the PVC baseboards in your office or at a commercial building or hospital. The uses of PVC never cease to amaze me. The product goes through many different phases and by products before it is turned into deck boards, but suffice to say you already own PVC products that have lasted for years. With the typical product being 5/4” thick and spans capable of up to 16” on center, PVC offers lasting performance and color choices that really do look like wood. However, with PVC synthetics you will experience a color fade, although not as significant as wood filled composites. The PVC’s color can be brought back with a pressure washer or a couple of different PVC renewing chemicals. Consider the fact that unlike wood composites, you can pressure wash PVC decking without the fear of damaging the decking. Just use some common sense in the amount of pressure and stay away from the heated steam pressure washer. PVC synthetics will be around for years with minimum maintenance and will be beautiful for its lifespan.

HDPE is just as familiar to your household as PVC. They are most commonly found as a milk jug, or laundry detergent bottle. The biggest advantage to the HDPE over the PVC is that HDPE is the most environmentally friendly product available to the decking industry. Some HDPE products are up to 80% recycled from post industrial recycling streams. In other words, they melt and shred all of the milk and detergent bottles they can find and use them to make something beautiful, while at the same time helping the environment by keeping these waste products out of our landfills. The interesting thing about HDPE is after the product has finished its time as a decking product, it can be sent to the recycling facility to start the process all over again. How long will it last? Well, most of the industry engineers say that it will last well over 100 years. How’s that for long lasting? With HDPE decking, you have a couple of choices in how the product is made. The first method is extrusion. This means the melted HDPE is forced through a dye that shapes it as it passes through and then is immediately cooled. The product is then embossed with a grain on one side and then cut to length. This extrusion produces a very smooth finish on the un-grained side and produces a very consistent color on both sides. The un-grained side is very popular for use as seating or handrails because of its soft feel. The extruded HDPE also has the advantage that no other decking material has in that it can be shaped, cut and routed just like a piece of wood because it is solid and the color is consistent all the way through the board. That’s right, if you use a high quality extruded HDPE synthetic product you can do just about anything with it you need. HDPE also has the ability to be made into 2×6 or larger dimensions to span 24” on center thus being the perfect product for that old dock or deck that was framed to support wood decking at 24” centers.

The second method used to manufacture HDPE synthetic products involves using molds. This method is very popular for structural HDPE products. Fiberglass and other non organic materials are added to the HDPE to achieve a structural rating. This method does not produce the silky smooth appearance of the extrusion method, but results in a more matte finish. People have commented that with the finish a little duller than extruded HDPE, the board has a lot more character. I’ll let you be the judge of that. No matter which method of achieving a HDPE board, it will outlast just about everything on the market and some brands can even achieve less than 3% fading over 10 years. In Florida, where I live, that is unheard of.

No matter which product is right for you, I would urge you to ask a couple of key questions when shopping new decking options;
#1 Is this a PVC, HDPE or Composite?
#2 If it is a composite, does it contain organic or non organic filler?
#3 Does the product contain ANY wood or organic fillers?
#4 Does this product have a warranty? If so, how long and what is covered?
#5 Where can I see a job done with this product that is at least two years old?
#6 Always check the internet for research on litigation issues against the specific manufacturer of the product you are interested in, Google the brand name specific and search for reviews. Remember that everything looks great when it’s brand new, but what does it look like in three or four years?

Decking has come a long way and we can all benefit from the technological advances in modern decking materials. Wood worked well for centuries, wood filled composites made a huge advance in decking science and brought us to the future of the decking industry, synthetics. No matter your application, there is a product on the market to meet your needs and using synthetics your project will have a life expectancy that is longer than your own.