1. What is Deck Footing Spacing?

Deck footing spacing refers to the calculation of how many footings are needed to properly support a deck based on the total load and the capacity of each individual footing. Proper spacing ensures structural integrity and safety.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( Load \) — Total weight the deck needs to support (lbs)
• \( Capacity\ per\ Footing \) — Weight-bearing capacity of each individual footing (lbs/footing)

Explanation: The formula divides the total load by the capacity of each footing to determine how many footings are needed.

3. Importance of Proper Footing Spacing

Details: Correct footing spacing prevents deck sagging, bouncing, or collapse. It ensures even weight distribution and complies with building codes.

4. Using the Calculator

Tips: Enter the total expected load on the deck (including people, furniture, snow load, etc.) and the capacity per footing. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine the total load?
A: Include dead load (deck weight), live load (people, furniture), and environmental loads (snow, wind). Typical residential decks use 50 psf (pounds per square foot).

Q2: What's a typical footing capacity?
A: Capacity varies by soil type and footing size. Common capacities range from 3,000 to 6,000 lbs per footing in good soil conditions.

Q3: How does soil type affect footing capacity?
A: Sandy soils have lower capacity than clay or rocky soils. A geotechnical engineer can provide precise soil bearing capacity.

Q4: Should I add a safety factor?
A: Yes, most professionals recommend a safety factor of 1.5-2x the calculated load for additional margin of safety.

Q5: Are there building code requirements?
A: Yes, local building codes specify minimum requirements for footing depth, diameter, and spacing based on frost lines and seismic zones.