HOW TO POUR A CONCRETE POST FOOTING USING A FREE CARDBOARD FORM
Removing an old fence post along with its concrete footing often leaves behind a massive, unmanageable hole. Your first instinct might be to run to the home improvement store to buy a commercial sonotube or a specialized concrete form to fill the gap. However, there is a much cheaper and easier way to solve this issue using materials you probably already have lying around the house.
THE CARDBOARD BOX HACK
Instead of purchasing a store-bought form or wasting extra bags of concrete to fill the entire oversized cavity, simply grab an old cardboard box. You can easily bend and shape the scrap cardboard into a cylinder right inside the hole. This acts as a perfect temporary form to hold your wet concrete tightly in place while you work.
THE LAYERING TECHNIQUE
To ensure your new footing is strong and stable, do not pour all the concrete into the cardboard at once. The trick is to build it up in stages. Pour a small layer of concrete inside the cardboard form, and then backfill a little bit of dirt around the outside of the cardboard. Pack the dirt firmly to hold the form rigid. Repeat this process, alternating a layer of concrete on the inside and a layer of dirt on the outside, until you reach the top of the hole.
CRUCIAL DRAINAGE TIPS
As you finish your pour, you need to pay close attention to the very top of the concrete. Always shape and slope the top surface slightly so that rainwater naturally drains away from the center of the post. If the concrete is perfectly flat or dipping inward, water will sit there and eventually rot your wood.
Additionally, try to avoid burying the top of the concrete under the soil. Make sure the finished concrete sits at least one inch above the ground level so ground moisture is not constantly trapped against the base of your structure.
CONCLUSION
By using this simple cardboard trick, you can save money on supplies and extra concrete while quickly repairing oversized post holes with professional-grade results. Keep these tips in mind for your next backyard fencing or deck project to save a trip to the hardware store.
