How to Build a Composite Deck

If you have a fun, comfortable composite deck space outdoors. Then you can spend a nice weekend outside with family and friends, grilling, dining, or chatting over a cup of coffee.

You may be thinking that building a deck is difficult, so you can break it down into smaller sub-projects so that building a basic deck will be much easier. In the process, you will know what you are doing and will help you build the deck.

Important

The WPC joist should be installed on the flat, sturdy ground with good ventilation and drainage. Before installing the joist, confirm that the maximum rainfall in the installation area does not exceed the height of the joist. It is recommended to use concrete to harden the ground and have a drainage slope of 1-2%. Please make a reasonable plan for the decking project before starting to install the joist which is very important to the safety and beauty of the project.

Codes and Permits

In most areas, you will need to apply for a building permit from your local government before you can proceed with building renovations. One of the benefits of building a deck or floating patio, on the other hand, is that permits are often not required to stay below a certain height.

This project has a deck attached to the house, a situation that usually requires a permit. Also, because decks can be built higher, they need to have railings and handrails.

When to Build a Deck

Early fall is prime time to build a composite deck. As the temperature drops in the fall, it’s a good time to get some outdoor work done. It needs to be done before winter sets in, though. If you decide to do it yourself, you may also choose to start in late spring. Then you’ll have a longer time to work.

Before building a deck

The location for building a deck should be flat and free of other obstacles. You can access the deck from the back or side door of the house. Do not place the deck flush with the height of the house floor. Instead, the deck should be lowered at least 3 inches.

Choosing Decking Materials

Composite deck. Made of recyclable plastic as well as wood fibers, it does not need to be stained or coated. It won’t crack, rot, warp, or splinter. And it requires little to no maintenance, which can reduce significant time and labor costs.

Pressure-treated lumber. This wood is inexpensive. The downside is that it produces wood spurs, making it unsuitable for barefoot walking. Over time, this type of wood decorative decking can also crack and warp.

Cedar. Cedar is about twice as expensive as pressure-treated lumber, it is usually insect-resistant and easy to stain. The downside is that it also has a tendency to crack and warp.

Tropical hardwoods. Tropical imported hardwoods, such as ipe, represent high-end decking materials. Their hardness and density mean they do not absorb stains well and require oil to protect them. Tropical hardwoods must be secured to the joists with special hidden clips.

The Cost of Building a Deck

Cost is one of the biggest concerns. Building a small attached deck will cost $2,000 to $5,000, depending on the size of the deck and the materials used.

The choice of decking material is a major factor in the overall cost of a deck. Pressure-treated wood decking costs $2.50 to $4 per square foot. Composite decking costs $9 to $15 per square foot. The highest prices are for tropical hardwoods, such as ipe, at $17 to $20 per square foot. But when you consider the cost of maintenance later in the year, composite decking costs are lower.

Composite deck Installation

1. Normally, the joist should be laid as vertical to the decking as possible, the gap between the joist should be no more than 14” (350mm). If the joist and the decking cannot be vertical, please select the corresponding joist gap according to the angle between the joist and the decking. Leave 1/4″–1/2″ (6–13 mm) gap between the end of the joist and the obstacle.

2. At the butt seam of the decking, the sister joist MUST be used so that each individual decking board is on its own joist to ensure that the board will not slide off the joist, otherwise the warranty will be invalid. leave 1/5″ (5mm) between the two joists for ventilation and drainage.

3. Fix the joist with expansion screws. Ensure that the expansion screw is installed at the center of the joist. The distance between expansion screws should not exceed 20” (500mm).

NOTE: When fixing accessories on the WPC joist with screw, always pre-drill the pilot hole before securing the screw to avoid damage to the joist. 

4. Fix the other composite decks to the keel in the above order. Pay attention to the 8mm interval between each deck to prevent the deck from deformation caused by heat expansion.

To ensure that your deck railing meets code, follow these guidelines

The railing must be at least 36 inches higher than the top of the deck floor.

The distance between posts cannot exceed 6 feet.

Vertical railings between posts should be no more than 4 inches apart – from side to side, not from center to side.

When to call a professional

Building your deck yourself can save on labor costs. If it’s a single-level, square or rectangular deck, it’s easier to build it yourself. If you want other shaped, multi-level decks, it’s best to hire a professional.