Begin by laying four concrete blocks on the ground, two at each end, and two in the middle to form the base of the bench.
Place the wooden beams on top of the blocks, parallel to each other.
Use your measuring tape to ensure that the distance between the blocks is equal on both sides. This will ensure that your bench is level and stable.
Drill screws through the wooden beams into the blocks to secure them in place.
Repeat the process for the second layer of blocks, placing them on top of the wooden beams.
This second layer will form the backrest of the bench. So, make sure the blocks are aligned perfectly and securely attached with screws.
For additional support, you can add a third layer of blocks on the sides of the bench base and secure them with screws.
Lastly, you can sand down the edges of the blocks to create a smooth finish and paint the bench with your desired color to give it a more polished look.