How to Build a Deck
Time Required: Over 1 day
Learning how to build a deck in your outdoor space can enhance your home’s options for entertaining and relaxation. It can also be a demanding job, so carefully plan the amount of decking you’ll need and enlist any helping hands that you can. This guide will teach you how to build a ground level deck with step-by-step instructions.
● Wear hearing and eye protection when using power tools.
● Wear eye protection when using striking tools.
● Wear a dust mask when cutting lumber and mixing concrete.
● Do not wear gloves when operating power saws.
● Use GFCI-protected power cords when operating corded power tools outdoors.
● Use manufacturer-approved hardware and fasteners for all wood products.
- This guide will cover how to build a ground-level deck that does not require stairs and a stair railing. In many areas, a ground-level deck is defined as one that has a maximum height of 30 inches above the ground and is not attached to the house.
- Ground-level decks typically do not require a railing around the perimeter, and they may not require a permit. Ground-level decks also do not include the use of a ledger board in their design. Check with your local building department to determine your local code requirements when building a ground-level deck.
- If your deck calls for concrete piers or footings set in the ground, call 811 before you dig. Your local utility company will mark the location of any water, gas and power lines in your yard. Avoid digging near any marked lines. Dig holes using a post hole digger or two-person auger. You can use our tool rental services to rent an auger and make quick work of digging holes. If using an auger, avoid any areas marked by the utility company. To be safe, dig by hand if a hole needs to be located within 18 to 24 inches of a marked utility.
- While you have a good amount of flexibility in choosing the location of a free-standing ground-level deck in your yard, there will likely be some building code requirements to take into account. Your local building department will specify how far away from property lines a deck will need to be built, so be sure to check before moving forward. Also consider accessibility for getting building materials to the area. Lastly, a flat, level area is the best place for a free-standing ground-level deck.
- When determining how to build a deck, consider what type of deck board you’ll want. Composite decking boards installed with hidden fasteners create a clean look and low-maintenance finish. There are a variety of composite decking styles and colors to choose from. Pressure-treated wood decking is a common, budget-friendly option that can be stained any color you want. Keep in mind that pressure-treated wood and other wood species decking require regular maintenance.
- Once you have a general idea of the design you want, bring your ideas to your local Home Depot for a detailed drawing. You can use this drawing to estimate deck materials, and to submit to the local building department for code approval. Keep in mind that if your deck requires a permit, the building inspector will need to check various stages of the deck build process.
- Ground level decks are usually one step up from the ground, so won't require deck stairs, railing or stair railing unless it is higher than 8 inches.
Depending upon your area and local building codes, some decks may only require ground-level footings. In most instances, decks require support from concrete piers that are set into the ground. The terms “piers” and “footings” are often used interchangeably though they are technically not the same thing. Piers transfer the deck’s weight into the soil. Footings spread the weight out over a larger area. Depending upon building code requirements and soil conditions in your area, footings may also be required beneath the piers to spread the deck’s weight out. These specifications will be detailed in your deck drawings and guided by local building codes. Your deck drawings will indicate the size, number and location of deck piers or deck footings.
- Begin by using batter boards and mason's string lines to lay out the location of the piers and footings. This will provide the deck’s foundation. Batter boards are temporary frames used to mark the elevation and location of the corners of your deck.
- Lay out the deck perimeter using batter boards and mason’s line. Start by running a mason’s line parallel to the house first. Then run perpendicular lines to complete the perimeter, crossing the mason’s line at the corners.
- Square the corners using the 3, 4 ,5 method. Measure 3 feet from where the lines intersect and make a mark on the string line. Measure 4 feet along the line that runs perpendicular to that line and make a mark. Measure between the 3-foot and 4-foot marks and adjust the line until the marks are exactly 5 feet apart.
- Mark deck pier/footing locations using spray paint based on the drawings.
- Use a posthole digger or power auger to dig holes for the piers/footings.
- Be sure to dig below the frost line, if required by your local code.
- Place concrete tubing forms in the holes and level them so that they stick up about 1-inch above ground level. You can use scrap 1x screwed to each side of each form to help hold it level. The scrap 1x pieces should be long enough to stretch across the hole, suspending the tube in it.
- Use the mason’s lines and a tape measure to center the tubes according to the drawings, adjusting the hole locations as needed.
- If you want to have all the piers the same height, use a long level. This isn’t usually necessary, though, as any inconsistencies can be made up in the post lengths that will be set on top of them.
- Backfill the holes around the tubing forms, tamping the soil down every so often as you go.
- Mix ready-mix concrete bags in a wheelbarrow per the manufacturer’s instructions using a shovel or mortar hoe.
- Pour the mixed concrete into the tubing form, then place a post anchor bolt into the center of each footer before the cement begins to harden. Leave enough of the bolt above the footing to connect to the post base. Note: Use a mason’s string line stretched across the tubing forms to align the anchor bolts.
- Allow time for concrete to cure according to manufacturer’s instructions.
- Once the concrete has cured, set post bases over each anchor bolt and align according to layout indicated on the drawings.
- Don’t tighten the wood post base down all the way; leave the nut loose enough so that the base can be tapped in either direction later. The bolts can be tightened later, once the posts are set where you want them.
- Your deck plans likely call for posts to be set on each post base to be bolted to the deck framing later. In some cases, your deck plans may call for a beam to be set directly in the post bases.
- If plans call for posts, cut them a few inches above the finished height of the deck framing. You can cut them flush later.
- Set the posts in the post base and attach with appropriate post-base hardware nails or screws.
- If your deck plans call for a flush beam (a beam set within the same plane as the deck’s framing), set the beam directly onto the post bases. Use metal strapping hardware or composite shims to fine-tune the beam level. Don’t use wood shims as they will compress over time.
- Attach the beam to the post bases using post-base hardware nails or screws.
- Check beam alignment and adjust as needed to make sure beams are square.
With the posts or beams in place, it’s time to build the deck frame. Because the deck is free-standing, it does not require a ledger board, which gets attached to the house. Instead, your deck will consist of rim joists that make up the deck’s perimeter, to be filled in with joists that will support the decking.
- If building a low-level deck that is connected to posts set within the framing, attach the rim joist to the posts using galvanized 10D common nails, or 3-inch galvanized screws. Use one fastener per post as these are just temporary. Use a long level and a helper to ensure the rim joist is level.
- Install the remaining rim joists in the same manner to create the perimeter of the deck.
- Secure the rim joist to the posts using the appropriate hardware indicated by the drawings and your local building code. In most cases, specially-designed structural screws may be used, galvanized through-bolts or galvanized lag bolts.
- Cut the posts flush to the top of the rim joist so that the decking can sit freely over it later.
- If the beams represent the ends of the deck, finish the sides by installing a rim joist on either side. The perimeter of the deck is now comprised of a beam on either end, and a rim joist on either side.
- Add any additional hardware required by code, such as angle brackets.
Tip: Most framing lumber has a slight bow in it along its edge. This is called a “crown.” Install the rim joists and all framing materials so that the “crown” is up.
With the deck’s rim joist complete, it’s time to install the joists.
- Start by laying out the joist spacing on opposing rim joists. Pull your tape measure across the rim joist and mark the joist location which will be every 12, 16 or 24 inches, per your drawings. If your deck is comprised of two beams, pull your measurements along the beams and mark the beams.
- Repeat this process across the rim joist (or beam) parallel or opposite the one you just marked. Be sure to pull your layout from the same side of the rim joist as you did in the previous step.
- Go back and use a square to mark a line down the inside face of the rim joist / beam and place an x on the side of the line that is opposite from where you pulled your measurement from. So if you pulled your measurement from the left, place the x on the right of the line. If you pulled your measurement from the right, place the x on the left side of the line.
- These lines indicate the side of the joists and the x is where the ends of the joist will go.
- It’s typically easier to install joist hangers now, but you will need to make sure that they are placed at the proper height. If you’re installing the joists between the beams, you’ll have to install the joist hangers first.
- To install joist hangers, you can make a simple template using a cut end of the joist material that’s about 3 to 4 inches long. Nail a scrap piece of lumber on top of the cut joist piece so that it hangs over the end about 1 to 2 inches. Now, use this template to register the joist hanger on as you set it.
- Set the template so that the top registers on the rim joist, and the cut end of the joist piece sits where the joist will go. Holding the joist hanger to the template, nail each hanger in place using the appropriate structural nails or screws (hold the sides of the joist hanger slightly loose so that you can slide the joist in place later). Repeat until all hangers are installed.
- Measure the joist length using the area closest to the ends (the area in the middle may have bowed in or out slightly). Now cut all of the joists to length, and set in the joist hangers.
- Nail the joists using hardware-appropriate structural nails or screws.
- If you’re installing your joists between two rim joists instead of a beam, you can install the joists first and then the joist hangers later.
- Cut the joists to length, then nail them on the layout from the outside of the rim joist using galvanized 10D common nails.
- With the joists in place, go back and install the joist hangers using the hardware-specific structural nails or screws.
- Remember to crown the joists before you install them.
- Now, add self-adhesive flashing tape across the tops of the joists to help prolong the life of them. This is an optional step that adds some cost, but is becoming a best practice among professional deck builders.
- If your deck will be free-standing against the house, you’ll want your wood decking boards to run parallel to the house. If your deck will be out in the yard, then you’ll need to make the decking run parallel to the deck framing itself.
- To start the decking so that it’s parallel to the house, align the edge of the first deck board so that it is parallel to the house and run the fasteners in. Let the ends run long on either side.
- If you’ve pre-planned and are sure you will end with a full-sized board, you can start against the house and move outward.
- If you are not sure where the final board will land, start with the board farthest from the house and move toward the house.
- Continue running boards in this way, maintaining the appropriate spacing between boards. If using hidden fasteners, the fasteners have spacing built into them. If face-screwing pressure-treated wood decking, maintain about a 1/8 to 3/16-inch spacing between boards. 1/8-inch is typically recommended as the decking will tend to dry over time, shrinking and making the gap larger. You do want to have space between the deck boards to allow for drainage and air-flow.
- As you install the decking boards perpendicular to the joists, drive two fasteners through each board into the center of each joist. Position each fastener 3/4 to 1 inch from the edge of the board.
- As you move to the end of the deck (or towards the house), measure the distance at each corner to ensure you are moving in a straight line and will end parallel to the rim joist (or house, depending upon the direction you’re going).
- If running deck boards on a deck that is not near the house, start by snapping a line that is equidistant at each corner and allows for 1-inch to 1-1/2-inch overhang along the length of the first board.
- Install the first board as above, and repeat the process.
Tip: For the best appearance, stagger the seams between adjacent rows of decking. Seams should look random so keep them two or more joists away from one another.
With the boards in place, it’s time to trim the ends.
- Start by pulling a measurement of 1 inch or 1-1/2 inches at each corner, then snap a chalk line across the decking ends to connect the two.
- Repeat the process on the opposite edge.
- Cut along the line using a circular saw. To ensure a precise cut, screw or clamp a temporary guide for the circular, or use a track saw.
- When the cuts are complete, you can go back and run a router equipped with a bottom-bearing 1/4-inch round-over bit to ease the edge. If you don’t have a router, a sander equipped with 120-grit sandpaper will work as well.
Learning how to build a deck requires a command of basic carpentry and a commitment of time and resources. Once completed, a deck adds value to your home and helps you enjoy the outdoors in greater comfort.
When determining how much lumber you need, don’t guesstimate, calculate. Know exactly how much you need with our project calculators. For more help when constructing a deck, contact our experts in the Installation Services department.