How to Choose the Right Sliding Gate for Your Property

Thinking about installing a sliding gate to update your entrance, save space, or secure your property? This guide walks you through how to accurately measure for a sliding gate, common mistakes to avoid, and how to select the best gate for your outdoor space.

1. Measure the Width Between Gate Posts

Measure the inside distance between the two gate posts at three different heights:

A

Top

B

Middle

C

Bottom

Why three measurements? Posts may not be perfectly parallel—especially on older installations or if they've shifted over time.

Record the smallest of the three measurements—this is your usable gate width.
If the difference between measurements is more than 1/2 inch, check the alignment of your posts before installation. For example: If you measure 119.3" at the top, 118.5" in the middle, and 118.9" at the bottom, use 118.5" as your width.

2. Measure the Height from the Ground to the Underside of the Post Cap

Next, measure the total height available from the finished ground level up to the underside of the post cap (or pillar cover).

• • Take this measurement on both sides, as the ground may slope slightly.
• • The final gate height should be 2 to 4 inches less than the available space to allow for hardware clearance and smooth operation.

Make sure the rack and gate motor (if using automation) will fit without interfering with the gate height.

4. Check Ground Level and Alignment

Before installing a sliding gate, make sure the ground is level and solid. If the surface is uneven, the gate could drag, get stuck, or wear out faster.
The ground should be firm, with no holes or bumps—even small level differences can cause issues. If needed, pour a straight concrete pad (called a threshold) along the full width of the opening.

If your driveway slopes, consider a cantilever gate (which doesn’t require a ground track) or adjust the concrete to create a level base. Before installation, always use a laser or bubble level to check that everything is straight—this ensures your gate will slide smoothly and last longer.

Summary:

Measure the width between posts at the top, middle, and bottom. Use the smallest measurement.
Measure the gate height from the ground to the post cap.
Allow for side clearance at least equal to the gate width plus 20 inches.
Check that the ground is flat and stable. Install a concrete threshold if needed.

If you’re unsure, contact a professional for on-site measuring—this is the best way to ensure a perfect fit.