Civils

A Comprehensive Guide for a Perfect Deck

Building a sturdy and long-lasting deck is not only about selecting the right materials but also about ensuring proper support placement. At The Decking Block Company, we know that one of the most critical factors in deck construction is determining how to space your decking supports accurately. Properly spaced supports ensure your deck’s structural integrity and longevity, providing a safe and enjoyable outdoor space for years to come.

In this guide, we’ll explore the key aspects of decking support spacing, including why it’s crucial, how to calculate it, and tips for ensuring a solid foundation.

Why Is Support Spacing Important?

Correct spacing of your deck’s supports is crucial for:

1. Load Distribution: Ensuring even weight distribution across the deck surface. Too few supports can lead to sagging, while too many can result in wasted materials and effort.
2. Structural Integrity: Properly spaced supports prevent your decking boards from warping or bending under pressure, creating a flat and secure surface.
3. Compliance with Building Regulations: Following the recommended spacing ensures your deck meets local building codes and safety standards, avoiding costly repairs or rebuilds.

Factors That Influence Support Spacing

Several factors determine how far apart your decking supports should be. These include:

• Type of Decking Material: Composite, hardwood, and softwood decking all have different load-bearing capacities.
• Deck Height and Size: A large or raised deck requires more support than a smaller, ground-level deck.
• Joist Spacing: The spacing between your deck joists directly impacts the spacing of your support blocks.
• Load Requirements: Will the deck hold heavy furniture, a hot tub, or a lot of foot traffic? The more load, the more support you’ll need.

General Guidelines for Support Spacing

While exact measurements can vary depending on the factors above, here are some general guidelines for support spacing:

1. For a Ground-Level Deck

For a ground-level deck (up to 600mm high), you’ll want to place supports:

• Every 1.5m to 2m along the perimeter of the deck.
• Between 1m to 1.5m apart for internal supports. The spacing depends on the size of your joists and decking boards.

2. For a Raised Deck

If your deck is higher than 600mm off the ground, it will need additional support due to increased load:

• Support blocks should be placed every 1m to 1.5m along the perimeter.
• Internal supports should be no more than 1m apart to ensure proper weight distribution.

3. For Larger Decks or Heavy Loads

For decks that will hold heavy loads (like a hot tub or large furniture), the supports should be:

• At most 1m apart on the perimeter.
• Internal supports spaced 0.75m to 1m apart, depending on the load-bearing capacity of your materials.

Step-by-Step Process for Spacing Deck Supports

Now that you understand the basics of support spacing, here’s how to properly space your supports step by step:

Step 1: Measure and Mark

Start by measuring the total area where your deck will be installed. Mark out the perimeter of the deck, and then mark out where your support blocks will go. Make sure your spacing matches the type of deck and material you’re using.

Step 2: Place the Perimeter Supports

Once the markings are in place, install the support blocks around the perimeter of your deck first. Use a spirit level to ensure that each block is level and stable.

Step 3: Install Internal Supports

After setting the perimeter, work your way inward, spacing your internal supports based on the deck design and weight load. Make sure they’re evenly spaced and aligned with the joists for maximum support.

Step 4: Double-Check the Alignment

Before you start laying your decking boards, double-check the alignment of your supports. They should be level and securely positioned to prevent any shifting.

Take the Guesswork Out: Use Our Decking Block Calculator!

To make things even easier, we offer a free decking block calculator. This handy tool helps you quickly determine how many support blocks you’ll need based on the size and shape of your deck. Simply enter your deck dimensions, and the calculator will provide an accurate count of decking blocks required, ensuring you have the right amount to build a safe, secure deck without any unnecessary overspending.

Using our calculator removes the guesswork from planning and ensures you get the perfect number of supports every time.

Tips for Success

• Consider Joist Spans: The span of your joists will affect the spacing of your supports. Shorter joist spans require more supports, while longer spans need fewer but stronger supports.
• Use Quality Decking Blocks: Investing in high-quality, durable decking blocks ensures your supports will remain stable and last for years. Our blocks at The Decking Block Company are designed for easy installation and maximum strength.
• Check Local Building Codes: Always check with your local council or building authority to ensure your deck complies with any building codes, particularly if it’s raised above a certain height.

 

Properly spacing your decking supports is essential for a strong and secure deck. By following the guidelines outlined in this post and considering factors like the type of deck, load requirements, and joist spacing, you can ensure a perfect build. And with the help of our Decking Block Calculator, you’ll know exactly how many blocks you need, saving you time, effort, and money.

At The Decking Block Company, we offer a wide range of top-quality decking blocks that make your installation easy and durable. Feel free to contact us if you need further advice or assistance with your decking project!

When installing decking on uneven ground, it’s essential to create a stable and level base to ensure the longevity and safety of the structure. Here are some common methods and supports used for decking on uneven ground:

Concrete Footings

Poured concrete bases that provide a solid and stable foundation for deck posts, concrete footings provide a solid and stable base for decking.

Pros:

• High Stability: Excellent support and stability for large or heavy decks.
• Durability: Long-lasting and resistant to shifting or settling.
• Code Compliance: Often required by building codes for elevated or attached decks.

Cons:

• Labour-Intensive: Requires significant time and effort for digging, pouring, and curing.
• Cost: More expensive due to materials and labor.
• Weather Dependency: Needs good weather conditions for installation.

Best For: Large, permanent decks, especially those attached to a house.

Installation Process

Here’s a basic outline of the installation process:

• Mark the Deck Area: Outline the area where the deck will be installed.
• Dig Holes for Footings: Dig holes at regular intervals to the frost line depth.
• Pour Concrete: Pour concrete into the holes to create footings.
• Install Post Anchors: Place post anchors into the wet concrete to hold the deck posts.

Adjustable Deck Supports (Deck Risers or Pedestals)

Adjustable deck supports, also known as deck risers or pedestals, allow for precise levelling of the deck surface:

Pros:

• Easy Levelling: Simple height adjustments to accommodate uneven ground.
• Flexibility: Can be used on various types of terrain.
• Quick Installation: Faster and easier to install compared to concrete footings.

Cons:

• Load Limitations: May not support as much weight as concrete footings.
• Cost: Can be expensive, especially for high-quality adjustable supports.
• Material Durability: Often made of plastic, which may not be as durable as other materials like metal or concrete, potentially degrading over time due to weather exposure.

Best For: Medium-sized decks where quick installation and adjustability are important.

Installation Process

Here’s a basic outline of the installation process:

• Position the Supports: Place adjustable supports at regular intervals under the decking framework.
• Adjust Height: Twist or screw the supports to raise or lower the decking to the desired level.

Post and Beam Construction

This traditional method involves creating a framework of posts and beams to support the decking.

Pros

• Strong Support: Provides excellent support for large decks.
• Versatility: Suitable for a variety of deck designs and terrains.
• Durability: Long-lasting and stable foundation.

Cons

• Complex Installation: Requires precise measurements and alignment.
• Labour-Intensive: Significant effort needed for digging and setting posts.

Best For: Large, permanent decks, particularly on uneven terrain.

Installation Process

• Install Posts: Set posts in concrete footings at regular intervals.
• Attach Beams: Secure horizontal beams to the posts to create a level framework for the decking.

Ground Screws

Ground screws are a modern and efficient alternative to concrete footings, especially useful for uneven terrain.

Pros

• Minimal Excavation: No need for extensive digging.
• Quick Installation: Fast to install with the right equipment.
• Environmentally Friendly: Less disturbance to the ground compared to digging.

Cons

• Special Tools Required: May require special machinery or professional installation.
• Soil Compatibility: Not suitable for all soil types, especially very rocky or extremely soft soils.

Best For: Projects requiring minimal ground disturbance and quick installation.

Installation Process

• Screw into the Ground: Use a machine or hand tool to screw the ground screws into the earth at regular intervals.
• Attach Deck Framework: Secure the decking framework to the tops of the ground screws.

Concrete Blocks

Precast concrete blocks can be used as a simple and quick solution for supporting decking.

Pros

• Ease of Use: Simple and quick to install with no curing time needed.
• Cost-Effective: Generally less expensive than poured concrete footings.
• Mobility: Easy to move and reposition if needed.

Cons

• Stability: Less stable and secure than poured footings, especially on soft ground.
• Shifting: Can shift or settle over time, requiring adjustments.

Best For: Small to medium-sized, freestanding decks on relatively level ground.

Installation Process

• Place Blocks: Lay concrete blocks on the ground in a grid pattern to support the deck framework.
• Adjust for Level: Use shims or other materials to adjust the height of the blocks and level the decking.

Floating Deck

A floating deck is not attached to the house and “floats” on the ground.

Pros

• Flexibility: Can be moved or reconfigured easily.
• Easy Installation: Less complicated to install compared to fixed decks.
• Cost-Effective: Generally cheaper due to simpler design and materials.

Cons

• Limited Height: Typically built low to the ground.
• Potential Movement: More likely to shift or settle over time.

Best For: Small, temporary, or movable decks on relatively flat ground.

Installation Process

• Prepare the Ground: Level the ground as much as possible.
• Use Pavers or Concrete Blocks: Place pavers or concrete blocks directly on the ground to support the deck.
• Build Frame on Supports: Construct the decking frame on top of the pavers or blocks.

Summary

• Concrete Footings: Best for stability and durability; ideal for large, permanent decks but requires more effort and cost.
• Adjustable Deck Supports: Great for easy levelling and quick installation; suitable for medium-sized decks.
• Ground Screws: Quick and minimal disturbance; ideal for projects needing fast setup but not suitable for all soil types.
• Concrete Blocks: Easy and cost-effective; good for small, freestanding decks.
• Post and Beam Construction: Strong and versatile; suitable for large decks but labour-intensive.
• Floating Deck: Flexible and easy to install; best for small, low-to-ground decks.

Tips for Success

• Site Preparation: Clear and prepare the site by removing vegetation and debris. A layer of landscape fabric can help prevent weed growth.
• Drainage Considerations: Ensure proper drainage by sloping the ground slightly away from structures.
• Building Codes: Check local building codes and regulations for deck construction to ensure compliance.
• Safety: Wear appropriate safety gear and consider hiring a professional if you’re unsure about any part of the process.

Each of these methods can be adapted to suit the specific requirements of your site and the design of your deck.