Pilings provide the critical support for a structure. Wood choice for the pilings will determine the longevity of the structure. Pine-treated pine and cypress are two woods you can use. Both are durable and long-lasting, but finer differences between them will help you choose the best option for your pilings.
During pressure treatment, a softwood, like pine, is infused with a preservative to enhance its longevity and durability. Builders use pressure-treated pine for projects, such as railroad ties or underwater pilings, that are exposed to weather extremes. The treatment makes the wood more resistant to rot and decay. The type of treatment product applied to the pine dictates where the wood can be used.
Treated Pine for Pilings
Treating pine with a preservative and pressure makes it more durable. Creosote provides the best protection for pine to be used in pilings. When using creosote-treated pine, extended contact with the skin can cause irritation. Gloves should be worn when installing the pilings. For pilings used in the ground or for freshwater applications, look for a hazard rating on the pressure-treated pine of H5. If you are installing the pilings in saltwater, you will need a more durable H6. This rating reflects the amount of wood preservative used during the pine treatment.
Cypress is naturally durable and resistant to rot. Heartwood from an old-growth cypress tree is the most durable cypress available and is suitable for use in pilings. Today, old-growth cypress is difficult to find, and secondary growth makes a lower-quality substitute. If you can find old-growth heartwood from a cypress, it can be used for pilings without treatment due to its natural resistance to the elements.
Considerations When Using Cypress for Pilings
Pilings are best made with old-growth heartwood cypress, but if secondary growth cypress is the only kind available, treat it with a wood preservative before using it for the pilings. When constructing a pier or a deck, use a stronger wood than cypress for the walking surface planks. While pilings of cypress are strong, boards are not as resilient. Cypress boards are prone to warping, according to "Building and Designing Decks," by Scott Schuttner. When purchasing cypress pilings, you might find some cypress wood with natural pits, called pecks, in it. These come from a fungal infection, and while the holes do not affect the strength of the cypress, they do render it unsuitable for underwater use.
- Architectural Graphic Standards for Residential Construction; Dennis J. Hall, et al.
- Building and Designing Decks; Scott Schuttner
- The Encyclopedia of Wood; U.S. Department of Agriculture
- Great DIY Book; Gordana Trifunovic, et al.
- Builder's Instant Answers; Sidney M. Levy, et al.
- Photo Credit Thinkstock/Comstock/Getty Images