how to build a deck with concrete blocks

3 min read 23-01-2025

how to build a deck with concrete blocks

Building a deck with concrete blocks is a surprisingly affordable and durable option. This guide provides a step-by-step approach, perfect for DIY enthusiasts. Whether you're aiming for a simple patio or a more elaborate deck, this method offers versatility and strength. Let's get started on your concrete block deck project!

Planning Your Concrete Block Deck

Before you begin, careful planning is crucial. This phase determines the success of your project.

1. Design and Measurements

Determine the size: How large do you want your deck to be? Consider the available space and your planned use.
Sketch a plan: Draw a simple diagram showing the dimensions, block layout, and any features like stairs or railings. This helps visualize the project and calculate materials.
Check local regulations: Some areas have building codes that regulate deck construction. Verify any necessary permits or restrictions before starting.

2. Material Selection and Quantity

Concrete blocks: Choose hollow blocks for weight and cost savings. Calculate the number needed based on your design and block dimensions. Account for extras in case of breakage or errors.
Gravel base: A layer of gravel provides drainage and a level foundation. Estimate the amount needed based on the deck's area and desired depth.
Sand: A layer of sand ensures a level surface for the blocks. Calculate the required amount similarly to the gravel.
Decking material: This could be wood planks, composite decking, or even pavers. Choose a material that suits your budget and aesthetic preferences. Calculate the quantity based on your design.
Fasteners: Select appropriate fasteners for your chosen decking material.

3. Tools You'll Need

Gather all necessary tools before starting. This saves time and frustration.

Shovel
Level
Measuring tape
String line
Post-hole digger (if needed for support posts)
Wheelbarrow
Safety glasses
Gloves
Mason's trowel (optional for finer leveling)

Building Your Concrete Block Deck: A Step-by-Step Guide

With your plan and materials ready, it's time to build. This is the most hands-on phase of the project.

1. Site Preparation

Clear the area: Remove any existing vegetation, debris, or obstacles.
Level the ground: Use a shovel to create a level surface for your deck.
Compact the soil: Thoroughly compact the ground to prevent settling.

2. Base Construction

Gravel base: Spread a layer of gravel (approximately 4 inches deep) evenly across the area. Compact the gravel thoroughly.
Sand layer: Add a layer of sand (approximately 1 inch deep) on top of the compacted gravel. Level the sand carefully using a level and a straight edge.

3. Laying the Concrete Blocks

First course: Lay the first course of concrete blocks, ensuring they are level and aligned. Use a level to check frequently. You may need to adjust the sand layer for a level base.
Subsequent courses: Continue stacking the blocks, ensuring each course is level and aligned with the previous one.
Block bonding: For added stability, you can use mortar between blocks, particularly for taller structures.

4. Decking Installation

Attaching the decking: Once the concrete block base is complete, attach your chosen decking material. This process varies depending on your chosen material. Ensure proper spacing for expansion and contraction.
Securely fasten: Use appropriate fasteners to ensure a strong and secure connection between the decking and the concrete blocks.

5. Finishing Touches

Railings (if needed): Install railings if required for safety. Ensure they meet local building code requirements.
Steps (if needed): Construct steps using additional blocks or other suitable materials.

Maintaining Your Concrete Block Deck

Regular maintenance extends the life of your deck.

Clean regularly: Sweep or hose down the deck to remove dirt and debris.
Inspect for damage: Regularly check for cracks, loose blocks, or other damage.
Repair as needed: Address any damage promptly to prevent further problems.
Seal (Optional): Consider sealing your concrete blocks or decking to protect against weather damage.

Frequently Asked Questions (FAQs) about Concrete Block Decks

Q: How strong is a concrete block deck?

A: Concrete block decks are surprisingly strong and durable, able to support significant weight when properly constructed. However, it's crucial to follow building guidelines and ensure a strong, stable foundation.

Q: Can I build a very tall deck with concrete blocks?

A: While possible, taller decks require more careful planning and engineering considerations to ensure stability. Consult with a structural engineer if planning a tall structure.

Q: What are the disadvantages of a concrete block deck?

A: While durable and cost effective, concrete block decks may be less aesthetically pleasing than traditional wood decks to some. The construction process is also more involved than simple wood frame decks.

Q: What type of concrete blocks should I use?

A: Use standard hollow concrete blocks. Solid concrete blocks are far heavier and more expensive than necessary for most applications.

Building a deck with concrete blocks is a rewarding DIY project. With careful planning, attention to detail, and the steps outlined above, you can create a durable and functional outdoor space. Remember safety first and always consult local building codes before starting your project.