You’ve settled on a deck for your next DIY project, and you’re ready to start. Trouble is, you’re not sure how to take that first step. It may seem like a simple endeavor, but as you’re well aware, the little details make all the difference.
With that in mind, we’ll walk you through everything you need to know. Follow this easy guide, and you’ll build a wooden deck in no time at all.
1. Determine the Size of the Framing Material
The first step to building a deck is collecting the framing material: the beams, piers, ledger, and joists. You’ll need to adhere to a few rules as you measure these components:
When you’re working with beams or rim joists from doubled-up 2x lumber, your boards’ nominal width in inches should match the span in feet.
You’ll make the ledger from a single board of the same width, so pay close attention to the dimensions of the previous components.
For interior joists, halve the span and add two. A joist spanning 8 feet will require a 2-by-6.
Remember to round up any fractions or odd numbers to the next even number.
2. Attach the Ledger to the Side of Your Home
Once you’ve measured your framing material, you’ll attach the ledger to the side of your home. Remove the trim and siding 1 foot above where you want the ledger to sit. Use a self-adhering waterproof membrane to cover the exposed sheathing, then mark the exact location at the top of the ledger.
As a side note, the step downward to the finish decking on top of the ledger must be 4 to 7 3/4 inches beneath your door sill. Snap a level line in chalk, and you’re free to proceed. When you’re confident in the placement of your ledger, cut a treated wood spacer that’s 2 inches wide and 1 1/2 inches thick for every 24 inches of ledger length.
Next, line the ledger up with the tops of the spacers and use 16d nails to nail it to the wall at each individual spacer. Then drill a 3 3/8-inch pilot hole through your ledger into your home’s rim joist at each spacer in a zigzag pattern. Insert a 1/2-inch lag screw in each hole and tighten it to your washer with an impact wrench.
3. Safeguard the Ledger With Metal Flashing
You’ll have to protect your ledger after you’ve attached it to your home. Cut a piece of waterproof membrane that’s 6 inches wide and the exact length of the ledger, then fold it lengthwise to form a right angle. Press it against the ledger-to-house joint so one leg extends up the wall and the other is covering the top of the ledger and spacer blocks.
Manipulate a piece of metal flashing in the same way, cutting it 6 inches wide and the length of the ledger. Fold it lengthwise and place it on top of the membrane. When the flashing is firm against the membrane, hammer your roofing nails every 8 inches through its top edge.
When you’ve attached the flashing to the membrane, you’re free to affix your concealed flange double joist hangers to each end of your ledger. Make sure they’re tight to the edges along the bottom and use joist hanger nails to secure it. Upgrade your stone patio or walkway in mind if you’re planning to connect it to your new deck and make sure it’s not damaged in your construction.
4. Decide on Your Footings and Piers
You can use mason’s strings and batter boards to figure out the footing locations at the deck’s outside corners. Place them at 8-foot intervals along the front rim joist, and mark the locations before you momentarily remove the mason’s strings. At each of the footing locations, dig a hole that’s wide enough for the footing form and deep enough that it passes below the frost line.
Then, assemble your footing and pier forms by following the manufacturer’s instructions. Position one in each hole and backfill. As for the pier’s finish height, you can run a level line from the very top of your ledger to the pier tube, measure down by 1/16 inch every foot of the distance between the pier and your house — in addition to the height of your post base and rim joist.
Make sure to mark the form at the point you’ve found, and repeat the process for each pier, trimming the pier tubes at your marks. After you’ve checked the piers’ positioning, fill the area with concrete and use a shovel to work out any air pockets. Give the concrete about one week to cure.
5. Set Your Side Rim Joists and Post Bases
Position a post base on top of a pier so it doesn’t interfere with your joist hangers, then mark its location. Remove it and use a hammer drill with a masonry bit to bore into the piper. When you’ve drilled the hole, reposition the post base and use an impact wrench to tighten an anchor bolt, repeating the process for each pier.
Prepare your pressure-treated 2x stock to use for your doubled side rim joists and beams. Use construction adhesive to glue them up and nail them together from both sides every 16 inches in a zigzag pattern with 12d nails. Then, place a side rim joist in the joist hanger at one of the ends of the ledger, squaring the corner.
After you’ve fit the side rim joist, use 16d nails to toenail through the hanger into the ledger. Set the opposite end of the joist on a corner pier, and repeat the process with the other side joist as you remove mason’s strings. You can cut your 2x stock for your deck’s front rim joist, staggering any butt joints as you vary the board lengths.
6. Install Your Beams, Interior and Rim Joists
You’ll continue to develop the structure of your deck with your beams, interior and rim joists. Start by fastening your double joist hangers to the furthermost part of the inner 2xs of your front rim joist. Secure your inner 2xs in your post bases, then move on to your side rim joists.
For your side rim joists, you’ll need to square their corners and fit them in your front hangers. Use hanger nails to affix your front rim joist 2x to your post bases, then use six 16d nails to attach your front rim joist to the side rim joist’s end. You can repeat the process with your other side rim joist.
Once you’ve covered that step, you’ll want to attach the face-mounted double joist hangers you’ve gotten for your beams along your ledger and front rim joist, flush to the edges at their bottom. Fasten them every 8 feet on center, fitting and nailing each beam in the same way you handled the others.
You’ll manage your doubled front rim joist when you glue and nail the outer 2xs to the inner 2xs. Then, you’ll have to install your 2x joist hangers along your beams, 16 inches on center. Fit and toenail your joists through your hangers and remember to install your joists crown-side up if they have a crown.
7. Secure the Trim and Decking
Collect paint-grade trim boards that are the width of the rim joists and secure them to their outside faces using two 8d stainless finish nails. Space them every 12 to 16 inches. You’ll want to miter the joints at the corners and scarf any joints in the run.
Next, you’ll need to assess the distance between the outside of your trim board and the wall, adding an inch for overhang. Cut your deck boards to that length. Apply a polyurethane marine sealant along the top edge of a side rim joist, and lay a straight deck board on the adhesive with its long edge overhanging the trim board by an inch.
Use an 8d finish nail to attach each end of your deck boards, tacking them into the joists alongside the first board as you dab adhesive onto the top edge of every joist. Lay the next board and nail it down as before, gluing and nailing until you’ve finished. When you’re done, replace your home’s siding to within 1/2 to an inch of the decking.
8. Remain Mindful of Ventilation
As a final note, ground-level decks will attract mold if you don’t provide proper ventilation. When you’re building a ground-level deck, make sure that air can flow beneath it. The ground should slope away from the house under ground-level decks to prevent any issues with moisture and rotting.
Take the First Step Today!
As you brush the dust from your clothing and put away your supplies, you’ll feel proud of yourself for following through on your project. Take the first step today!
Scott Huntington is a writer from central Pennsylvania. He enjoys working on his home and garden with his wife and 2 kids. Follow him on Twitter @SMHuntington