Aluminum Decking Verses Treated Wood and Composites

Few building materials offer the flexibility and strength of aluminum. Combining it’s non- corrosive properties, longevity and minimal negative impact on our environment, aluminum is one of the greenest building products available. Made from bauxite ore, the most abundant metal on earth, together with being the second most recycled product makes aluminum very sustainable with an unlimited lifespan.

Utilizing extruded aluminum and bonded finishes consumers can achieve the look, design, and longevity combined with strength for all their outside projects. Posts, decking and rails constructed of aluminum will last 50+ years and offer virtually no maintenance.

Natural oxidization, a white film surface coating, is an extremely stable compound that does not flake off like rust on iron. This property makes aluminum the metal of choice in many components from aerospace, transportation, buildings and marine applications. It is quickly rising in residential construction for decks, docks, railings and fences.

Some Material Properties of Aluminum:

Corrosion Resistant Non-Toxic

Durable High Strength to Weight Ratio

Recyclable Non-Magnetic

Non-Sparking Non-Combustible

Lightweight Attractive

Resilient Paintable

Longevity Cost Effective

Treated Wood

Wood treated with chromate copper arsenate has finally been banned by the EPA for residential use. However, it is still accepted for commercial construction, posts, foundations & marine applications. CCA wood leeches arsenic and other deadly toxins into our soils and water contaminating the very area we hope to enjoy. Research has found 15 year old treated wood still has extremely high levels of arsenic on the surface along with high levels in the soil nearby. These toxins easily absorb through the skin with contact and wash from their surfaces into the water poisoning our lakes and rivers.

Since the ban of CCA, other treated wood products have entered the market which are deemed safer, yet they still have many pesticides, fungicides, and other toxins to preserve the wood from natural decay. Few studies have been done on environmental impact and the health concerns of these new products. To be sure, prolong exposure to will have negative consequences across the board. Keep in mind, wood still has a very limited lifespan and requires much maintenance.

The most common treated wood now available is Alkaline Copper Quaternary. Building with ACQ lumber presents new challenges that must be addressed if we desire our projects to hold up for more than just a few years. Because of the high levels of copper, ACQ wood must be fastened with either stainless steel or hot dipped galvanized steel to avoid galvanic reaction between the copper and steel causing quick corrosion of fasteners. Structural integrity will be lost if high grade hot dipped galvanized steel or stainless steel fasteners are not used in all construction. Check for approved suppliers and do your due diligence with contractors.

Composite Woods

Over the last decade composite wood, or plastic wood has been touted as the ‘no maintenance’ solution to docks and decking. Much money has been spent to convince the public that composites are better than wood and will last forever. NOT TRUE.

Composites are made from sawdust and recycled plastics mixed with various fungicides, pesticides, and preservatives. Even with all these chemicals added, composites still mold and stain because wood absorbs moisture creating internal fungus growth. Many of the cleaners are extremely hazardous and only clean the surface leaving the cause untouched.

Wood composites are not structural components. Most manufactures suggest 12″OC or less for joists because composite wood will sag under it’s own weight. Also, some of the new lines with hollow cores are easily punctured with high heels or patio furniture. Furthermore, composites expand and contract a greatly with temperature changes, causing loosening of fasteners & boards.

Environmentally, composites just don’t cut it. Yes, they are made from post consumer waste, however they quickly become consumer waste that cannot be recycled or reused. They are associated with many health concerns both in construction and VOC (volatile organic compounds) emissions such as formaldehyde and other toxins linked to cancers, skin diseases and even respiratory problems.

Several lawsuits have been filed and a few settled with composite manufacturers. With big advertising budgets many people are lured to believe composite decking is a great choice. However, with minimal research one could spend days reading complaint after complaint on these products. Numerous composite manufacturing companies have shut down under one name only to reopen under another avoiding warranty issues. Composite woods are definitely a buyer beware product and not even close to ‘no maintenance’ and ‘lifetime warranty’.


Building materials for our outdoor living spaces need to be as clean and green as possible.

Often we are quite exposed being barefoot and barely covered while on our docks and decks.

Contact with toxic chemicals from wood or composites is never worth the cost.

Aluminum poses no such health concerns and will not rot, decay or pollute our soils and water. For decking and docks with no maintenance and lifetime durability, aluminum is the best choice for our children today, tomorrow and forever.