A DIY Homeowner’s Guide to Deck Building

A homeowner with DIY experience may well be tempted to tackle deck building since a deck is one of those projects where the professional labor costs more than the materials. By performing the labor, a DIYer has lots of opportunity for saving money on a deck. Further, the lifestyle benefits are significant because adding decking is a great way to expand family living space into the yard for a relatively low investment. When compared to similar projects, such as building a room addition, porch or gazebo, deck building is often more affordable and easier for most DIYers to tackle.

However, don't assume that deck building is easy just because the materials are fairly basic and the required tools are familiar. A sophisticated deck with multiple levels, geometric angles and complex stairways and railings is quite a major DIY project. If the goal is this kind of complex design, most homeowners prefer to have the work done by a professional builder.

A deck can be a very basic structure — little more than a wooden platform that rests on the ground — or it can be a very sophisticated, multilevel structure with stairways, railings or even a built-in arbor or gazebo. Most DIYers with a realistic assessment of their abilities build a floating deck, or a fairly simple rectangular deck, that serves to extend living space from a kitchen or dining room to the outdoors, or it might be a detached deck somewhere in your yard, serving as a platform to entertain guests or for other outdoor living activities.

Almost any DIYer with some experience with carpentry tools can build this kind of basic deck. Even some multilevel decks are within the reach of a skilled DIYer provided they are not elevated too high. Some multilevel decks aren't much more than two or more simple deck platforms connected together structurally.

Deck building becomes a much easier project if you understand the basic components of a deck. Virtually all decks use variations of the same structural elements, and if you understand how they work together, building a basic DIY deck should prove to be no great challenge.

All decks rest on some kind of ground footings. This can involve simple concrete piers that rest directly on the ground to support the beams beneath a ground-level deck, or the footings might involve deep concrete footings that anchor tall posts supporting an entire elevated deck structure. From the footings, most decks have vertical posts, usually 6x6 lumber that forms the main support for the entire deck structure.

A ledger board is used where a deck is attached directly to the home. It anchors into the wall framing and is carefully flashed to keep water out of the connection. Any deck that is attached to the house must have a foundation that is frost-protected so it won't rise and fall with the seasonal freezing and thawing of the ground.

Beams are the major horizontal support members that rest on the posts. They support the parallel horizontal joists that lie immediately beneath the decking boards that make up the deck surface​.​ With decks that are very low to the ground, these components — footings, beams, joists and surface decking — might be all that is required. However, any deck that is more than 30 inches above the ground will probably require additional components.

A railing with vertical balusters or horizontal rails spaced close enough to protect users from falling is usually required for any deck that is more than 30 inches above the ground. This is also the height at which a stairway down to the ground is often required. The stairway can range from a simple box step to a multistep stairway that requires its own railings and perhaps even an interim landing if the stairway is tall enough to warrant it. Many decks will have additional extras, such as skirting to hide the underside of the deck, vertical trellises or overhead arbors and possibly built-in benches.

At one time, decks were always built from wood of some type from top to bottom. While today's decks usually still use traditional pressure-treated lumber for the support structure, the visible surface decking and railing materials may well be some sort of synthetic decking material that offers long life and easy upkeep. Attractive lumber, such as redwood or cedar, is still a common material for the decking and other visible elements, but synthetic lumber is increasingly used for these elements.

The deck-building materials available at consumer home improvement centers include:

• ​Pressure-treated lumber:​ This type of lumber, impregnated with chemicals that retard rot and insect damage, is virtually always used for the load-bearing elements that are hidden from view. Pressure-treated lumber can also be used for surface decking and railings, but many homeowners choose more attractive materials for these elements. Pressure-treated lumber may be pine, spruce, fir or other softwoods. Southern yellow pine is a relatively high grade of treated lumber.
  
  
• ​Cedar or redwood lumber:​ These species of lumber are naturally resistant to decay, but because they are considerably more expensive than pressure-treated lumber, they are usually reserved for the visible elements of a deck, especially the surface decking and railings. Good-quality redwood has become a very expensive option, so most people seeking the look of attractive wood will opt for cedar for the surface deck boards and railings.
  
  
• ​Composite lumber:​ This material is made from a mixture of wood or bamboo byproducts and recycled plastics. It is an increasingly popular material for surface decking and railing components. It is now available in several different colors, and it may be texturized to resemble natural wood. Composite decking is slightly more expensive than good-quality cedar decking boards, but when the low maintenance and long life is factored in, it actually becomes the less expensive option.
  
  
• ​PVC vinyl decking​: Surface decking boards can also be made of solid PVC vinyl material. PVC decking can be up to 50 percent more expensive than composite lumber, but it comes in many colors and has a very realistic texture. Using PVC decking is one of the best ways to achieve a durable deck with designer appeal.
  
  
• ​Metal connectors and fasteners:​ All decks will use a large number of metal connectors and nails or screws for construction. Make sure to use hot-dipped galvanized or stainless steel connectors and fasteners. These will not corrode when contacting the chemicals in pressure-treated lumber.
  
  
• ​Concrete​: Poured concrete is used to form structural piers or footings to support the deck's vertical posts. With large decks, a DIYer may choose to have ready-mix concrete delivered, but it is also possible to mix and pour your own concrete using dry concrete mix sold in bags.

Serious accidents caused by collapsing decks are more common than you might think, and for this reason, just about every local building code has precise requirements for how a deck should be built. An early visit to your community's building inspection office is a very good idea since it can offer a wealth of information on subjects such as:

• ​Depth and size of posts and footings​. These factors are dictated by the size of the deck and the expected load that the deck must bear. In snowy climates, for example, the building code may anticipate that the deck may need to hold a substantial amount of heavy snow in the winter.
  
  
• ​Spacing and span measurements for beams and joists​. These dimensional requirements are designed to make sure the deck can adequately support the expected live load (the weight of people and furniture) that will be placed on it.
  
  
• ​Anchoring methods.​ If the deck will be attached to the house by means of a ledger, the building code will detail the proper way to do this. If the deck is freestanding, the code will govern how the posts must be anchored to the footings.
  
  
• ​Special requirements if you live in an earthquake or hurricane zone.​ Special tie-down metal connectors may be required if you live in a region subject to these natural forces.
  
  
• ​Permit and inspection details​. These requirements vary considerably by state or even from community to community within a state. It is essential, though, not to bypass the permit process if your community mandates it. The penalties for ignoring permit requirements can be substantial, and you can even be required to tear down a deck that is built illegally.

It's quite true that you can save a lot of money by building a deck yourself. It's also true that you can waste a vast amount of time and money if your skills turn out to be inadequate to do the job. Before deciding, do your homework. Make sure you have a specific blueprint or deck plans for the project you're envisioning and then read up on the techniques required. A DIY deck requires a fair amount of skill in several areas, from concrete work to basic carpentry to wood finishing.

Just as important as your own skill is your ability to enlist the aid of good helpers. While a single individual can certainly build a deck, the process can take many weeks. With two or three good helpers, the project can reasonably be finished in a couple of weekends.

If, after studying the work required, you decide that it makes more sense to hire professionals, make sure to choose your builder carefully. The same criteria used to hire any contractor also applies to hiring a deck builder. Interview only builders who have liability insurance that is current and check for a history of Better Business Bureau complaints. Also, look for a history of complaints posted in online forums, such as Angie's List and Yelp. A bad review here or there can simply be a fluke — or even the work of a competitor — but a contractor with an ongoing pattern of poor online reviews has probably earned those reviews for a reason.

Probably the best way to choose a builder is through word-of-mouth recommendations from friends or neighbors who own recently built decks that you admire. If you don't have that kind of social network, inquire at a local hardware store for recommendations for builders. Your neighborhood might also have an online chat forum, such as Nextdoor, where you can solicit recommendations for trustworthy and competent contractors.

Whether you are building a deck yourself or hiring a builder, the process follows pretty much the same sequence.

First, obtain whatever building permit is required by the local building department. With a working plan or blueprint in hand, you can now lay out the shape of the deck and the location of the support posts on the building site. Dig the post footings to the depth and spacing required by your local building code. Pour concrete footings and anchor the posts according to the building plan. Posts used to be embedded right in the concrete, but this promotes rot, so now it is much more common to attach metal anchors to the top of the concrete footings and then attach the posts to those anchors.

Once the concrete footings have fully dried and the posts are attached, horizontal beams are installed, supported by the posts. At one time, it was common practice to create these beams by sandwiching pairs of 2x8s or 2x10s around the posts, but most current building codes now require that the support beams rest on top of the posts and are anchored with bolts or metal framing connectors.

With beams installed, the joists are now installed, spaced according to the building plan and local code requirements. On a freestanding deck, the joists rest on top of two or more beams. If the deck is attached to the home or another structure, one end of the joists is usually attached to a ledger board anchored to the home's rim joist or foundation wall.

Next, the surface decking boards are installed over the joists, following the building plan. A uniform gap between boards is essential. Longitudinal joints between boards should be offset so they don't line up from row to row.

Railings and stairways are now installed — a process that is sometimes more complicated and time consuming than the construction of the deck itself. Here is where a considerable amount of carpentry skill is often required. Elevated decks that require long stairways with landings are especially complicated to build. The construction phase of the deck may also involve the building of an arbor, benches, skirting and other add-ons.

The last step will be to complete whatever staining or wood finish is required. The lumber manufacturer may recommend an aging period before applying a stain or sealer.