A deck adds outdoor living space to a house. Whether it’s used to host the social event of the season, to have a family meal, or just to relax and watch the sunrise or sunset, a deck is a valuable part of many houses.
About Deck Construction
Decks were once considered structures that anyone could build, but investigations of deck failures and research into deck construction practices have shown that decks are more complicated than people realize. As a result, building codes have mandated stricter standards for building decks in recent years, and many building departments are enforcing these stricter standards.
Deck inspections often reveal failures to comply with modern deck construction standards. Such compliance failures are common with older decks but can also occur with recently built decks. Some of these compliance failures involve safety issues. Building codes typically do not require that existing decks be brought up to current standards, however, when safety is involved, homeowners would be wise to address safety issues regardless of whether or not doing so is required.
The service life of deck components ranges between 10 years (or less) for decks located on the ocean to thirty years for decks in a dry environment. Twenty years is a good average to use in most environments.
What Is a Deck?
A deck is a structure generally made from wood that is usually located adjacent to the house. When most people think about a deck, they think about the structure located at the rear of the house. A deck can, however, be located anywhere on the property. A front porch may be a deck. A stairway and a landing serving a door may be a deck. If the structure is built like a deck, then it is a deck, regardless of where it is located and what it is called. If the structure is a deck, then the deck construction standards apply.
Types of Decking Materials
Choosing the right decking material helps increase its longevity, improve its appearance, and reduce the maintenance requirements needed. Here are the most common types of decking materials:
Wood Decking
Wood is the traditional choice for decking, offering a natural look and feel. Common wood species include:
- Cedar: Naturally resistant to rot and insects.
- Pressure-treated pine: Affordable and widely available.
- Redwood: Durable and aesthetically pleasing.
Pros and Cons of Wood Decking
Pros:
- Can be stained or painted
- Environmental benefits
- Natural aesthetic
Cons:
- Can splinter over time
- Requires regular maintenance
- Susceptible to rot and insects without treatment
Composite Decking
Composite decking is made from a mixture of wood fibers and recycled plastic. It offers several advantages:
- Available in various colors and textures
- Low maintenance
- Resistance to rot, insects, and fading
While more expensive initially, composite decking can be cost-effective in the long run due to its durability and minimal upkeep requirements.
Pros and Cons of Composite Decking
Pros:
- Less prone to warping and splintering
- Eco-friendly options available
- Long-lasting and durable
Cons:
- Can get hot in direct sunlight
- Higher upfront cost
- Limited options for customization
PVC Decking
PVC (polyvinyl chloride) decking is a fully synthetic option that offers:
- Excellent resistance to moisture and stains
- Lightweight and easy to install
- Low maintenance needs
PVC decking is often more expensive than wood or composite options but provides superior durability and longevity.
Pros and Cons of PVC Decking
Pros:
- High resistance to mold and mildew
- Very low maintenance
- Wide range of color options
Cons:
- Can be slippery when wet
- Can look less natural due to its synthetic nature
- Higher cost compared to other materials
Metal Decking
Metal decking, typically made of aluminum, is less common but offers unique benefits, such as:
- Exceptional durability and longevity
- Fire resistance
- Low maintenance requirements
While metal decking can be more expensive, it’s an excellent choice for areas prone to extreme weather conditions.
Pros and Cons of Metal Decking
Pros:
- Fire-resistant
- Recyclable
- Strong and durable
Cons:
- Can be noisy
- Higher material costs
- Limited aesthetic options
Decks Around Aboveground Pools
Decks are sometimes built around permanent aboveground swimming pools to provide access to the pool and a place to relax at the water’s edge. These decks present some special challenges.
Most local governments require an access barrier system around swimming pools to help keep children from entering the pool without supervision and possibly drowning. If the deck around the pool is part of the access barrier system, it must comply with some special requirements. These requirements can include a specific height for the deck and guards, as well as self-closing and self-latching gates that allow access to the pool deck.
Pool water contains chemicals that can deteriorate deck components. You should be careful when selecting and installing components for decks around pools. Consider stainless steel for hardware and fasteners and consult the manufacturer’s instructions when selecting deck flooring (decking) to ensure that it is designed to resist deterioration by pool water chemicals.
Parts of a Deck
Decks can range from a simple, single-level rectangle to a complex multi-level structure with angles and rounded turns. Whether simple or complex, most decks consist of the same components. While all deck components are important for safety and longevity, some are more important than others. The International Residential Code (IRC) outlines all of the requirements for decks. The following list is in order from the most important to the least important from a safety perspective.
1. Flashing
Flashing is required between the deck and the house when the deck is attached to the house. Flashing helps keep water from entering between the deck and the house. Water can damage the important connection of the deck to the house, which can cause the deck to collapse when it pulls away from the house. Water can also create conditions for fungal (mold) growth.
2. Ledger Attachment
Most decks are attached to the house. The board that attaches the deck to the house is called the ledger board, or ledger. The ledger must be attached to the house using bolts or screws. Nails, by themselves, are not acceptable. The deck must also be secured to the house using connectors called lateral load connectors (tension ties). Failure to properly secure the deck to the house can cause the deck to collapse when it pulls away from the house.
3. Guards (Guardrails)
A deck that is more than 30 inches above the ground is required to have a guard around the perimeter to keep people from falling from the deck. Many deck injuries are caused when the deck guard fails and people who are leaning on the guard fall to the ground. Building codes have requirements about the force that a guard must resist, but the codes provide no guidance about how to build a guard to resist that force. As a result, very few guards comply with the code requirements.
Building codes also have requirements for the height of deck guards above the deck flooring. A horizontal deck guard should be at least 36 inches tall, except in California, where the minimum height is 42 inches.
4. Stairways and Handrails
A stairway is required if the deck is more than 7 3/4 inches above the ground. A handrail is required if the stairway has four or more risers (the vertical part of the stairway). Injuries involving stairways are common. This is especially true for exterior stairways, which are exposed to rain and snow. Take special care when building exterior stairways and handrails.
Handrails and guards on the open sides of deck stairways should be at least 34 inches, and not more than 38 inches, above the leading edge of the stairway treads. Handrail shape requirements for all exterior stairways, including deck stairways, are the same as for interior stairways. A handrail made from a two-by-four or larger lumber is not a proper, or a safe, handrail.
5. Framing
Framing includes components such as floor joists, joist hangers, deck flooring, and the nails and screws that hold everything together. Installation of framing components according to building code requirements and manufacturer’s instructions is important, but it is unusual that framing errors are the sole cause of deck injuries.
6. Posts and Footings
Like framing components, installation of deck posts and footings is important, but it is unusual that improper installation of these components is the sole cause of deck injuries.
Deck Codes and Standards
It is important to know that a deck built in compliance with the local building code may or may not be safe. There are many reasons why this is true, including slow adoption of up-to-date building codes by local building departments and sporadic enforcement of building codes in some areas. In addition, building codes are a minimum standard. Building a deck beyond the minimum standard is recommended for both safety and longevity.
Deck Inspections
Experts advise that decks be inspected by a qualified professional. How often this occurs depends on the deck. Once a year is ideal for decks older than 10 years, while every two or three years may be acceptable for newer decks.
While not a substitute for a professional inspection, here are some things you can look for that might help you determine if your deck presents a significant safety risk.
- Guards move when you push on them.
- Joist hangers, nails, or other metal hardware present significant visible red rust.
- Stairs move or shake when you walk on them.
- The deck ledger is attached to the house using only nails or uses only small screws, such as deck flooring screws.
- The wood to which the deck ledger is attached to the house is soft when probed with a sharp object such as a screwdriver, or it shows water stains. The damage you can see from inside the basement or crawlspace may be worse where you can’t see it.
- Wood is soft when probed. This is especially common where posts are buried in soil.
Deck Maintenance and Longevity
In addition to getting your deck checked regularly, you should also clean your deck annually and apply a water-repellent sealer every two to three years. Composite and PVC decks may require less frequent cleaning overall.
If you notice an issue with your deck, address it promptly by replacing damaged boards or hardware as needed to prevent further deterioration. Keep spare materials on hand for quick repairs, especially for composite decking, where colors may vary between batches. Fully repairing a deck, especially if structural repairs are necessary, is usually best left to professionals. If you try, be sure to follow the manufacturer’s instructions for any joist hangers, connectors, and screws or nails that you install.
Perform seasonal maintenance, such as removing snow accumulation in winter and checking for mold growth in damp climates. Properly store deck furniture during off-seasons to reduce wear and tear.
Should You DIY Your Deck?
Building a deck is also usually best left to professionals. If the deck is not more than about three feet above the ground and is a simple rectangle, then experienced do-it-yourselfers (DIYers) may be able to try it, but you should have some experience building structures if you plan on giving it a shot. Many jurisdictions require a building permit to build a deck, so be sure to contact your local building department to learn their permitting and inspection requirements.
Enhancing Your Deck
You can also customize your deck to suit your lifestyle by adding some enhancements, such as:
Lighting Options
Install deck mood lighting for safety and ambiance. Options include post cap lights, stair lights, and string lights. Consider solar-powered lights for an eco-friendly option.
Furniture and Accessories
Choose weather-resistant furniture, outdoor rugs, and planters to create a comfortable and inviting space. Accessories such as cushions and throws can add color and comfort.
Built-In Features
Consider adding built-in seating, planters, or a pergola for shade and visual interest. A built-in grill or outdoor kitchen can turn your deck into the perfect space for entertaining.
Outdoor Heating
To extend the usability of your deck into cooler seasons, consider outdoor heaters or a fire pit. Be sure to install them carefully, following safety guidelines to prevent fire hazards.
Common Decking Problems and Solutions
As the life of your deck extends, you may run into some common issues, such as:
Warping and Splintering
Warping is caused by moisture exposure in wood decks. Regular sealing and prompt repairs can prevent these issues. Using high-quality, pressure-treated wood can also reduce the occurrence.
Fading and Discoloration
UV exposure can cause fading in both wood and composite decking. Choose materials with UV resistance or apply UV-protective sealers. Regular maintenance and cleaning can also help maintain the deck’s appearance.
Mold and Mildew Growth
Proper drainage and regular cleaning can prevent mold and mildew. Use a deck cleaner formulated for your decking material. Elevated designs can further improve airflow and reduce moisture buildup.
Rust and Corrosion
Metal components can rust or corrode over time, particularly in coastal areas with salty air. Use corrosion-resistant fasteners and perform regular inspections to identify and replace affected parts.
Cost Factors for Decking Projects
According to Angi, building a new deck typically costs anywhere from $4,341–$12,526. The size and location of the project will impact the cost, as well as the material you choose. The cost of decking material ranges from $2–$45 per square foot. Pressure-treated wood is the least costly at $2–$5 per square foot, while composite decking costs between $12 and $22, and aluminum/metal costs between $15 and $20 per square foot.
Labor costs between $15–$35 per square foot, depending on the complexity of the project, per Angi. There also may be additional costs such as permits, which can cost between $230 and $500, and added features such as a staircase ($25–$50 per stair) or outdoor lighting fixtures ($8–$30 each).
