🏗️ How To Build A Foundation

A solid foundation is the key to a long-lasting shed. At Outdoor Living Today, we want to help you create a sturdy, level base for your shed—without confusion or guesswork. Whether you’re a DIY pro or first-timer, this guide walks you through clear, step-by-step instructions and multiple foundation options.

 Three Recommended Foundation Types:

• Patio Stones (Fast & Easy)
• Pressure-Treated 4×4 Beams (Durable & Elevated)
• Concrete Slab (Permanent & Weather-Resistant)

STEP 1: Clear & Prepare the Site

Before your shed kit arrives:

• Remove grass, debris, roots, and rocks.

• Make sure the area is flat and drains well.

• The ground should slope away from the site (approx. 1/8″ per foot over 10 feet) to prevent water buildup.

• For best results, excavate 4 inches and fill with gravel or crushed rock.

💡 Pro Tip: Use a landscape fabric under gravel to prevent weed growth and soil shifting over time.

STEP 2: Mark Out the Shed Foundation

• Pick one corner (Point A) and drive a stake into the ground.

  Use the 3-4-5 triangle method (based on the Pythagorean theorem) to ensure your layout is square—this method works for any shed size:

  • Measure 3 feet (or any multiple) on one side, and 4 feet (or same multiple) on the adjacent side. The diagonal between them should be exactly 5 feet (or the matching multiple).

  • For larger sheds, you can use 6-8-10 or 9-12-15—just maintain the ratio.

  Once your corners are square, outline the full perimeter using string and batter boards.

📏 Need help squaring? There are apps and online calculators that can assist with right angles using your shed dimensions.

STEP 3: Choose Your Foundation Type

Patio Stone Foundation

• Best for small to medium sheds on stable ground.

• Level the soil or gravel, then place stones under key floor joist points (see your floor plan).

• Adjust using sand or soil for leveling.

• Space stones evenly to support the shed’s perimeter and any internal floor joists for balanced weight distribution.

• Use a long 2×4 and a carpenter’s level to ensure all stones sit flat and level across the entire footprint.

✅ Quick to install, affordable, and easy to move or adjust.

 

4×4 Pressure-Treated Beam Foundation

• Ideal for slightly uneven terrain or areas where airflow is needed beneath the shed.

• Lay beams perpendicular to joists on a gravel base.

• Use rebar (½”) driven through pre-drilled holes to secure beams in place.

• Leave space between beams to promote drainage and prevent moisture buildup under the shed.

• Ensure all beams are level and aligned before attaching floor joists for a stable, even base.

🪵 Leaves room underneath for ventilation and helps prevent rot.

 

Concrete Slab Foundation

• Best for large, heavy-duty sheds or long-term placement.

• Excavate 6 inches: 4″ of gravel, 4″ of concrete slab.

• Include a plastic vapor barrier between gravel and slab.

• Frame your pour with 2x4s, level and finish with a trowel or bull float.

🔒 Most permanent option. Offers unbeatable durability and pest resistance.

⚠️ Final Tips Before You Start:

• Always check local building codes and permit requirements.

• Call your local utility provider before you dig to avoid underground lines.

• Don’t skip drainage—it’s your best defense against rot and frost heave.

🔍 Need More Specific Foundation Guidance?
While this guide provides general best practices for preparing a foundation, individual product designs may have unique requirements. For a more tailored guide for your specific model, please refer to the provided product assembly manual included with your kit or available above .