How to Choose the Right Sliding Gate for Your Property

Thinking about installing a sliding gate to update your entrance, save space, or add security? This guide walks you through how to measure for a sliding gate step by step, highlights common mistakes to avoid, and helps you select the best option for your outdoor space.

1. Measure the Width Between Posts

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

A

Top

B

Middle

C

Bottom

Why measure three times? Posts aren’t always perfectly parallel—especially on older installations or if they’ve shifted over time.

Record the smallest of the three measurements. This is the usable width for your gate.
If the difference between measurements is more than 1/2 inch, check that the posts are plumb 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 reference 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 bottom of the post cap (or cover).

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

Make sure the rack and gate motor (if used) will fit without interfering with the gate’s movement.

4. Check Ground Level and Alignment

Before installing a sliding gate, make sure the ground is level and stable. If the surface isn’t flat, the gate may drag, jam, or wear out faster.
The base should be solid, with no holes or bumps, as even small uneven spots can cause issues. If needed, pour a straight concrete pad (called a threshold) along the full width of the opening.

If your driveway is sloped, consider a cantilever gate (which doesn’t require a ground track) or adjust the concrete to create a level base. Always check with a laser or bubble level before installation—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 value.
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.