1. What is Span-to-Depth Ratio for Fences?

Definition: The span-to-depth ratio (SDR) compares the horizontal span length to the vertical depth of fence components.

Purpose: It helps determine structural stability and appropriate dimensions for fence posts and panels.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( SDR \) — Span-to-depth ratio (dimensionless)
• \( S \) — Span length (meters, m)
• \( D \) — Depth (meters, m)

Explanation: The span length is divided by the depth to determine their proportional relationship.

3. Importance of Span-to-Depth Ratio

Details: Proper SDR ensures fence stability against wind loads, prevents sagging, and maintains structural integrity over time.

4. Using the Calculator

Tips: Enter the span length between supports and the depth (height) of the fence. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical SDR for wooden fences?
A: For most residential fences, SDR between 2:1 and 3:1 is common, depending on material and wind conditions.

Q2: How does SDR affect fence stability?
A: Higher ratios mean longer spans relative to depth, which may require stronger materials or additional supports.

Q3: When would I need a lower SDR?
A: In high wind areas or for heavy materials (like stone), lower SDR (1.5:1 or less) provides better stability.

Q4: Can I use this for other structures?
A: While the principle applies generally, specific structural calculations may be needed for non-fence applications.

Q5: How do I measure span length?
A: Measure center-to-center distance between fence posts or support structures.