It’s a question I get from everyone in the decking business, from vendors and installers to homeowners and real estate agents. There are several factors.
First, are we talking about an existing deck? If so, age is a factor in its age. For new construction, experience tells me that deck service life depends on:
- The choice of building materials
- The deck builder’s skill
- The climate
- The deck’s configuration and
- Maintenance practice
It’s that last one—maintenance—where homeowners have the most control over the lifespan of their existing deck. You’ll find the other factors are important to consider when you want to repair or replace the deck and need to decide which materials to use.
If you repair the deck, you keep it in service at the least cost. But by replacing the deck boards—and updating the joist flashing while you’re at it—you extend the service life much more. Building a new deck is also a good option since a deck adds value, returning about 50 percent of your investment. That’s a higher payback than you get from remodeling a kitchen or bathroom.
Based on my years of experience, here are my tips on how to assess the life expectancy of your outdoor living space. I also provide some tips on how to keep the deck in service longer.
Wood Deck Lifespan
Wood is the traditional and most common decking option. It has a natural appeal and is available in various species and over a wide price range. How long a wood deck lasts depends a good deal on the type of wood you use.
Pressure-treated wood, typically fir and pine, is a popular choice. These softwoods are infused with preservatives and resist decay, insect damage, and fungal growth. The level of treatment indicated on the label determines where pressure-treated lumber can be used. Some are suitable for ground contact (deck structure), and some are for above-ground use only (decking boards).
A deck covered with pressure-treated wood can last anywhere from 10 to 30 years, depending on where it’s used (climate), the quality of the wood, and how well it’s maintained. Regular maintenance, including washing and refinishing, will maximize the deck’s longevity. But not everyone is up to that, and I’ve seen many wood decks fail prematurely from neglect.
Cedar and Redwood
These two natural wood species are more resistant to decay and insects than untreated pine and fir. Even so, they need refinishing every couple of years to maintain their desirable appearance. With proper maintenance, redwood and cedar decks can last 20 to 30 years.
Like cedar and redwood, this type of hardwood decking is naturally resistant to the effects of water and insects but it’s more durable. Popular species include mahogany, ipe, and teak. These species have gained popularity for high-end decks and can last several decades. I’ve seen ipe decking outlast elements of a deck’s support structure.
How Long Does Composite Decking Last?
A well-maintained composite deck can last 25 to 30 years or even more, depending on the quality of the material and the climate conditions.
Known for its durability and low maintenance, composite decking materials such as Trex combine wood fibers and plastic. The quality of the composite material and its resistance to fading and deterioration vary among manufacturers and product lines. The higher-cost options tend to last longer and offer more colors, textures, and accessory options.
Composite decking typically requires the support framing to be 12 inches on center, which nudges up the cost for the framing versus wood decking. Still, it’s a small fraction of the overall installation cost.
How Long Does a PVC Deck Last?
Well-maintained, a PVC deck will last 25 years or more, depending on the quality of the material. Like composite deck boards, PVC decking comes in various colors, textures, and accessory options. However, it contains no organic material that can harbor mold, mildew, or rot. While no-maintenance materials are a myth, some Timbertech PVC deck boards carry a 50-year warranty against fades and stains.
Factors That Influence the Lifespan of a Deck
In addition to the building materials you select, builder skill, climate conditions, and deck configuration also factor in deck longevity.
We sell to many contractors who specialize in deck building, and the best ones are usually busy, so plan ahead. Look for experienced installers. They’ve seen how decks fail and how to protect them. Here’s my advice for DIY’ers: Talk to the local building inspector. Understand how to place footings and anchor the deck to the house on the ledger board. I also recommend using flashing tape for deck protection at the ledger board, joists, and beams. This is our easy-to-apply product that shields the “bones” of your deck from moisture and makes it last longer.
Exposure to the elements can take a toll on decks and deck railings.
Moisture and Rainfall
Decks in regions with high humidity or frequent rainfall are more susceptible to moisture-related issues like rot and mold. Proper drainage and ventilation are crucial in such climates. Likewise, freeze-thaw cycles can lead to the expansion and contraction of materials, and footings that are too shallow can “heave.”
Prolonged exposure to sunlight can cause fading and deterioration. Using UV-resistant finishes or choosing materials designed to withstand exposure to UV rays can mitigate this. Also, be aware that intense heat can dry out a wooden deck and cause the boards to crack and splinter.
Complex designs and elevated decks can be a challenge to support and frame.
Design and Structure
The framing scheme for the deck should distribute the load evenly to minimize stress on individual components. Multi-level and cantilevered decks require special attention. To maximize structural integrity and longevity, avoid large spans and verify that the lumber, hardware, and fasteners are rated for the job.
Elevated and hillside decks are susceptible to greater lateral forces from wind and deck loads. These decks may require specialty footings and additional bracing to ensure stability and longevity. Ground-level decks are at greater risk of moisture damage.
How Long Does Trex Decking Last?
Trex composite decking will last 30 years if properly installed and maintained. As one of the first companies to offer composite decking, Trex has implemented many innovations in material science and deck board manufacturing. Some product lines come with a 50-year warranty against fading.
Maintenance Tips for Prolonging the Lifespan of Your Deck
Even hardy materials like composite decking need upkeep to maximize their service life. Here are the basics of deck maintenance.
- Regular Cleaning. Keep the deck surface swept to prevent tree litter and other debris from accumulating. If not, moisture can build up and cause mold and mildew to grow. Scrubbing the deck at least once yearly with a soft-bristle brush and a mild detergent would be best. Rinse thoroughly. Don’t use chlorine bleach. It damages the wood fibers.
- Sealing and Staining. Applying a protective sealer or stain defends wood from the effects of UV rays and moisture. They also improve the look of the wood. How frequently your wood deck needs sanding and refinishing depends on its exposure to the elements, its age, and how much foot traffic it gets.
- Inspection and Repair. Watch for signs of wear, damage, and loose fasteners and/or hardware. Replace damaged boards, tighten or replace loose fasteners, and get help with structural repairs immediately.
By considering these factors and implementing appropriate building practices and maintenance routines, homeowners can significantly enhance the longevity of their outdoor space.