Your Guide to Building or Replacing a Solid Decking Foundation.

Don’t let a wobbly, sagging deck put a damper on your summer fun! The secret to a sturdy and long-lasting deck lies in its substructure. Whether you’re building a new deck or just replacing the decking, following best practices for the substructure can save you time, money, and headaches down the road. But before you strap on the ole tool belt, let’s determine whether you need a new substructure or not. 

How Can You Tell if Your Substructure Needs Replacing? 

Signs that it may be time to replace or upgrade your deck’s substructure include visible wear and tear, sagging or bouncing, loose or missing connections, inadequate spacing, pest damage, and structural issues. If any of these signs are present, it’s important to address them promptly to avoid safety hazards, structural issues, and costly repairs.

What If Your Substructure Doesn’t Need Replacing, But Your Decking Does?

If your substructure is in good condition but your decking needs replacing, pressure-treated Southern Yellow Pine (SYP) is a great choice for your new deck boards. SYP decking is a strong, dense wood product that can withstand heavy foot traffic, harsh weather conditions, and even insect damage. 

These natural attributes make it an ideal choice for decking, as it can hold up to years of use without losing its structural integrity. Not only is it a durable wood, but it has a distinct grain pattern and appealing golden color that can enhance any outdoor living space.

If you do need a new substructure, here are our top six pro tips to ensure a safe, long-lasting structure:

1. Use Pressure-Treated Wood

Using pressure-treated wood is important for the substructure of a deck because it is in constant contact with the ground and exposed to moisture. And few wood species are as well suited to pressure treatment as SYP. 

That’s because the wood boasts a unique cellular structure, making it the preferred species for pressure treatment. This process involves injecting the wood with natural perservatives to make it resistant to decay, insects, and other forms of damage.

2. Remember Size Matters 

When it comes to substructure best practices, the right size of lumber is essential to ensuring the structural integrity of your deck. Using undersized lumber can cause the substructure to sag, whereas using oversized lumber can add unnecessary weight and cost. Check with your local building codes to find out what size lumber is needed to meet safety and load-bearing requirements. 

3. Keep it Level Throughout

Ensuring that your substructure is level is crucial for the longevity and safety of your deck. If the substructure is uneven, it can cause the deck boards to warp, buckle, and become a safety hazard. Furthermore, an unlevel deck may not drain properly, which can cause water damage and rot over time.

4. Factor in the Environment

Wood, including pressure-treated (SYP), is one of the greenest building materials for several reasons. Firstly, wood is a renewable resource that can be sustainably harvested and replanted. Secondly, the production and transportation of wood require less energy and emit fewer greenhouse gasses than other building materials like steel and concrete. 

Lastly, wood is biodegradable and can be recycled or repurposed at the end of its lifespan. Pressure-treated SYP, in particular, is treated with eco-friendly preservatives that extend its lifespan and reduce the need for replacement, further reducing its environmental impact.

5. Properly Space Joists

The spacing of the joists is critical for the structural integrity of your deck. When joists are spaced too far apart, they cannot support the weight of the deck. Thus, causing it to sag and weaken over time. Be sure to follow the manufacturer’s instructions or building code requirements when determining the correct spacing. In terms of safety, this is one of the most important substructure practices to follow.

6. Build With Quality Hardware

Proper fasteners are essential to ensure the safety and longevity of your deck. It is crucial to use the appropriate hardware to secure your substructure to your house and to secure the joists to the beams. This helps prevent the deck from shifting, twisting, or collapsing, which could cause injury or property damage. So for optimal results, be sure to use ACQ-approved fasteners such as hot dipped galvanized or stainless steel.