How To Build A Porch Gate

Knowing how to build a deck gate is a beneficial skill for homeowners. Putting a gate at the top of your deck stairs is a simple safety solution. With a gate in place, your deck becomes a secure play area for your children and pets.


Before you start building, consider safety. International Building Code regulations are the most stringent guidelines you can use, so Mr. Handyman recommends following these rules when building your deck gate:

  • Hand rails and gates must be at least 42″ above the deck surface.
  • No gaps in or under the gate can be wider than four inches.
  • The gate must open onto the deck, not the stairs.


With just some basic tools and materials, you can add a simple but attractive gate to your deck. There are far worse ways to spend a sunny afternoon at home!

You will need:

  • Measuring tape
  • Table saw
  • Drill
  • Lumber – pressure-treated 2x4s and several 2×2 balusters, depending on the desired width
  • Wood screws
  • Two gate hinges
  • One gate latch
  • Four metal corner braces

Here is how to build a deck gate in eight easy steps:

  1. Measure the opening at the top of the stairs. Subtract one inch from this measurement to allow space for hinges and a latch. Cut two pressure-treated 2x4s to this length. These will make the top and bottom of your gate’s frame.
  2. Measure the desired height of the gate; remember that the bottom edge of your gate cannot be more than four inches above the deck surface. Subtract the width of the top and bottom boards (about 7 inches total) from your measurement, and then cut two 2x4s to that length. These will frame in the sides of your gate.
  3. Use three-inch wood screws to attach the four 2×4 beams together in an open rectangle, with the wider (3.5″) edges of the boards facing outward like a picture frame.
  4. Lay a 2×4 underneath the gate frame diagonally. Use a pencil to mark where you need to cut the ends of the cross member. Trim the 2×4 and screw it into place.
  5. Now you need to add balusters to the inside of the frame. Measure the inside dimensions of the frame and cut the desired number of 2×2 balusters to the appropriate length. Remember that you cannot have any gaps in the gate greater than four inches. Attach the balusters to the frame with wood screws. If you wish to paint your gate, do it before moving on to step 6. Be sure to apply durable exterior paint in a well-ventilated area – preferably outside. Allow the paint to dry completely before continuing to work on the gate.
  6. Next, add hardware to the gate. Attach two hinges (top and bottom) to one side of the gate and affix a latch barrel to the other side. Screw a metal brace into each corner for additional stability.
  7. Ask a friend to hold the gate in place, ideally resting it on a level support while you attach the hinges to the deck railing. Remember that the gate must open onto the deck, not the stairs.
  8. Attach the latch mechanism to the opposite side of the deck railing.

Congratulations, you have built and attached a deck gate.

Building an outdoor deck gate is a DIY project that can be achieved by even those new to home improvement. The following is an overview of the building process that outlines taking measurements for your gate, choosing and cutting materials, and making sure the frame is properly built.

Measuring the Width of Your Deck Gate

Making the measurements for your deck gate requires you to anticipate a few things. Start at the base of the stairs, and use a tape measure to determine the desired width of your gate. Subtract an inch to allow the gate to swing, as well as making room for the hinges and latch. Then measure how tall you’ll want the gate while keeping in mind that the bottom edge can’t be more than 4” above the floor of your deck.

Measuring the Space

The gate needs to swing back onto the surface of the deck. Typically, the gate is at the top of steps leading off the deck to the ground below. You’ll discover two handrail posts at the top of the staircase up on the deck. Your new gate is going to close off this opening.

Step 1: Use a 2-foot level and check each of the posts for plumb. Make a note if either of the posts are leaning towards one another, away from each other, or are out of plumb the same amount in one direction creating a parallelogram.

Step 2: Use your tape measure to record accurate measurements 4 inches up from the surface of the deck and as the code requires, 42 inches up off the surface of the deck. Draw a rough picture of the opening on a piece of paper or scrap lumber and record these.

Selecting the Wood

The most appropriate wood for your gate depends on your budget, climate, and color preferences. However, most people often choose pressure treated 2×2 balusters and 2×4’s. Whatever your choice, avoid low-grade lumber for building a deck gate because it’s prone to shrinking or warping, which can impair the functionality of a gate.

Choose lumber that has vertical grain to minimize warping and twisting. When you look at the ends of vertical-grain lumber, you’ll be able to see the center of the tree in the best pieces.

Cutting the Wood

While keeping in mind the gate can’t be more than 4” above the deck, cut the top and bottom gate frame horizontal 2x4s to the length required based on your measurement between the posts making sure to subtract the amount so the gate can open and close without touching the posts.

Cut the two vertical side-frame 2×4’s to the desired length based on your measurements. Temporarily lay the pieces of 2×4 on the deck with the wide face (3.5-inch) facing down and up to the sky. Without screwing it together, assemble the frame to measure its inside dimensions and determine the desired length of your balusters. Then cut your 2×2 balusters to length.

Building The Frame & Adding Balusters

The strongest corners you can create are half-lap joints. You do this by carefully cutting away 13/16ths of an inch of wood a little over 3.5 inches wide from the end of each 2×4. Overlap the pieces of lumber and then use six countersunk 1 and 1/4-inch galvanized screws to lock the corners together. It’s a good idea to also use exterior wood glue on the overlap joints just before installing the screws. As you assemble the outer frame, be sure to check that the shape of the gate matches the actual shape of the opening where it will fit.

The result should look similar to a photo frame. The quantity and precise placement of balusters is up to you, as long as the gaps between them do not exceed 4”. Connect the top and bottom halves of the frame, and then individually add balusters with wood screws.

Painting or Staining the Wood

Staining can be a time-consuming portion of learning how to make a wooden deck gate. With pressure-treated lumber, it is absolutely necessary to stain or paint the wood. Without this protection, Mother Nature will undo all your hard work in a matter of a few years. Allow the assembled gate to air dry in the shade or a garage for a week or two if the treated lumber seems extremely wet. Once it’s painted or stained, allow it to dry before adding hardware or attempting to install the gate.

Adding Corner Braces

Corner braces are one of the most commonly overlooked steps in how to make a deck gate. They’re important because they help evenly distribute force across the entire frame. After painting or staining, use a drill to screw metal braces into each corner of the frame to help ensure lasting stability. A brace about 9 inches long on each leg offers great strength.

Your half-lapped corner joints may not require this extra reinforcement. That said, it’s a great idea to add L-shaped galvanized corner braces made by Simpson Strong-Tie. Use their approved outdoor-exposure structural screws to attach the braces to the gate.

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