Step-by-Step Guide: How to Build a Concrete Block Bench

Transforming ordinary concrete blocks into a functional and stylish bench can be an incredibly rewarding DIY project. Not only does it allow you to create a unique piece of outdoor furniture, but it also helps you make the most of your space while keeping your budget in check. In this comprehensive guide, we'll walk you through the process of making a bench with concrete blocks, from planning to completion.

Before we dive into the step-by-step instructions, let's discuss some key considerations. First, decide on the size and design of your bench. A standard bench is about 4 feet long and 1.5 feet deep, but you can adjust these measurements to suit your needs. Also, consider the height - typically, a bench seat is around 18 inches off the ground. Next, choose a location for your bench that's level, well-drained, and receives the right amount of sunlight based on your preferences.

Gathering Materials and Tools

To ensure a smooth construction process, gather all the necessary materials and tools before you start. Here's a list to help you prepare:

• Concrete blocks (standard 8-inch by 8-inch by 16-inch blocks)
• Gravel
• Sand
• Cement
• Water
• Bucket
• Trowel
• Wheelbarrow
• Shovel
• Level
• Tape measure
• String line and stakes
• Gloves
• Safety glasses
• Optional: Sealer or stain for finishing

Preparing the Site

Before laying the first block, prepare the site by clearing any debris and ensuring the ground is level. If necessary, use a shovel to remove high spots and fill in low spots with soil or gravel. For added stability, you can also create a base of compacted gravel to support your bench.

Once the site is prepared, mark out the dimensions of your bench using stakes and a string line. This will serve as a reference as you build your bench and help ensure it's square and level.

Mixing Concrete

Mixing concrete is a simple process that involves combining cement, sand, and gravel in the right proportions. A common mix is one part cement to two parts sand to three parts gravel. Pour the dry ingredients into a wheelbarrow or large bucket, then gradually add water while mixing until you achieve a consistency similar to thick oatmeal.

For this project, you'll need to mix enough concrete to fill the voids between the concrete blocks and create a solid base for your bench. A good rule of thumb is to mix one 80-pound bag of cement with three 0.5 cubic foot bags of sand and four 0.5 cubic foot bags of gravel.

Building the Bench

Now that you have your materials and site prepared, it's time to start building your bench. Begin by laying the first course of concrete blocks along the length of your bench, following the marked dimensions. Use a level to ensure the blocks are even and aligned.

Once the first course is laid, fill the voids between the blocks with your concrete mixture, using a trowel to pack it in tightly. This will create a solid base for your bench and help prevent weeds from growing between the blocks.

Laying the Second Course

After the concrete has set for a few hours, begin laying the second course of blocks on top of the first. Stagger the joints between the blocks in the second course to create a stronger structure, similar to how bricks are laid in a wall. Again, use a level to ensure the blocks are even and aligned.

Fill the voids between the second course of blocks with concrete, just as you did with the first course. Continue this process, laying alternating courses of blocks and filling the voids with concrete, until you reach the desired height for your bench seat.

Creating the Seat

For the final course of blocks, which will serve as the bench seat, lay the blocks flat instead of on their sides. This will create a smooth, even surface for sitting. Fill the voids between these blocks with concrete as well, ensuring the top surface is level and smooth.

Once the concrete has set for a few hours, use a trowel to scrape off any excess concrete from the surface of the blocks. Allow the concrete to cure for at least 72 hours before using your bench to ensure it reaches its full strength.

Finishing Touches

After the concrete has cured, you can apply a sealer or stain to protect the bench and enhance its appearance. Choose a product that's specifically designed for concrete and follows the manufacturer's instructions for application. This step is optional but can help extend the life of your bench and make it more resistant to stains and weathering.

Adding Comfort

To make your bench more comfortable, consider adding a cushion or padding to the seat. You can purchase a pre-made bench cushion or create your own using outdoor fabric and foam. Secure the cushion to the bench using ties, straps, or brackets to prevent it from blowing away in windy conditions.

Alternatively, you can build a simple wooden seat frame that fits on top of the concrete blocks. Attach a piece of outdoor-rated plywood or composite decking to the frame, then add a cushion or padding for comfort.

Congratulations! You've now created a unique and functional bench using concrete blocks. Enjoy your new outdoor space and the sense of accomplishment that comes with a job well done. As you sit back and relax on your new bench, consider how you can continue to enhance your outdoor living area with more DIY projects and creative touches.