how to build a deck on concrete blocks

3 min read 07-02-2025

Meta Description: Learn how to build a sturdy and attractive deck on concrete blocks! This comprehensive guide covers materials, planning, step-by-step instructions, and safety tips for a successful DIY project. Transform your outdoor space with this easy-to-follow tutorial, complete with helpful images and expert advice. Building a deck has never been easier!

Planning Your Deck on Concrete Blocks

Before you even think about grabbing a hammer, careful planning is crucial for a successful deck-building project. This section will help you prepare for building a deck on concrete blocks.

1. Design and Measurements

Determine Deck Size and Shape: Decide on the dimensions and shape of your deck. Consider the available space and your desired aesthetic. Sketch out your plan, noting the exact measurements.
Choose Your Materials: Select pressure-treated lumber for its durability and resistance to rot and insects. Consider composite decking for a low-maintenance option. You'll also need concrete blocks, joist hangers, and fasteners.
Check Local Building Codes: Before starting any construction, confirm that your plans comply with all local building codes and regulations. Permits may be required depending on your location and deck size.

2. Selecting Concrete Blocks

The right concrete blocks are essential for a stable deck. Consider these factors:

Size and Strength: Choose blocks appropriate for the weight of your deck. Larger blocks provide a more stable base. Check the manufacturer's specifications for weight capacity.
Number of Blocks: Calculate the number of blocks you need based on your deck's dimensions and the spacing between the blocks. It's always better to have a few extras on hand.
Leveling: Ensure the blocks you choose are level and consistent in size to create a stable foundation. A slight variation can lead to an uneven deck.

3. Preparing the Site

Proper site preparation is paramount for a level and stable deck.

Clear the Area: Remove any grass, weeds, debris, or existing structures from the area where you plan to build your deck.
Level the Ground: Use a rake and level to create a flat and level surface. This ensures that your deck sits evenly on the blocks. Compact the ground to prevent settling.
Check for Utilities: Before digging or placing any blocks, contact your local utility companies to ensure that there are no underground lines or pipes in the construction area.

Building Your Deck on Concrete Blocks: A Step-by-Step Guide

This section provides a detailed step-by-step guide for constructing your deck.

1. Laying the Concrete Blocks

Mark the Perimeter: Use string and stakes to mark the perimeter of your deck. This will guide the placement of your concrete blocks.
Place the Blocks: Position the blocks evenly spaced around the perimeter, ensuring they are level and aligned. Use a level to check for evenness. Adjust as needed. Consider using gravel or sand for better leveling and drainage.
Secure the Blocks: If needed, consider using concrete adhesive to further secure the blocks in place, particularly on uneven ground.

2. Installing the Joists

Measure and Cut Joists: Measure the distance between the blocks and cut your joists to the appropriate length. Use a saw to cut the joists precisely.
Attach Joist Hangers: Install joist hangers to securely attach the joists to the concrete blocks. Follow the manufacturer's instructions. Ensure that the hangers are securely fastened.
Level the Joists: Use a level to ensure that the joists are level and parallel to each other. Make any necessary adjustments before proceeding.

3. Attaching the Decking Boards

Measure and Cut Decking Boards: Measure and cut the decking boards to fit the joists, ensuring a snug fit. You may need to cut some boards for the edges of the deck.
Attach Decking Boards: Attach the decking boards to the joists using appropriate fasteners. Maintain consistent spacing between the boards to ensure even airflow and drainage.
Finish the Edges: Once the decking boards are attached, finish the edges of the deck with appropriate trim or edging.

4. Adding Finishing Touches

Railings (if needed): If your deck requires railings, install them according to local building codes and regulations. Ensure they are securely fastened and meet safety standards.
Staining or Sealing: Protect your deck from the elements by staining or sealing the wood. This will enhance its durability and aesthetic appeal.

Safety Tips for Building a Deck on Concrete Blocks

Safety should always be your top priority when working on any construction project.

Wear Appropriate Safety Gear: Always wear safety glasses, gloves, and sturdy work boots.
Use Proper Tools: Ensure that you are using the appropriate tools for the job and that they are in good working condition.
Follow Instructions Carefully: Always follow the manufacturer's instructions for all materials and tools.
Get Help If Needed: Don't hesitate to ask for help if you are unsure about any step of the process.

Conclusion

Building a deck on concrete blocks can be a rewarding DIY project that adds significant value to your home. By carefully following these steps and prioritizing safety, you can create a beautiful and functional outdoor space. Remember to always check local building codes and consult with professionals if you have any doubts. Now get out there and start building!