Concrete picnic tables and patio furniture have become a popular choice for many homeowners and commercial property managers who want outdoor furniture with little maintenance and upkeep. Concrete picnic tables are durable, long-lasting and stand up to weather and everyday use much better than wooden picnic tables. Concrete picnic tables also provide built-in protection from thieves and vandals. When a concrete picnic table does become damaged or broken, you may be tempted to replace the unit. With the right materials, you can actually repair most types of breakages in a concrete picnic table yourself.
Mix concrete powder with water in a mixing container, or prepare a pre-mixed concrete solution according to the package instructions. The concrete solution should form a thick paste you can mold to hold the shape you form. The mixture should be completely moistened and easy to stir, but it should not be watery or runny. Continue mixing and add more water or concrete mix in small amounts to get the right consistency.
Spray the picnic table with a steady stream of water from a garden hose for about three minutes to moisten the area with the breakage. If you are repairing a complete breakage, soak the broken piece of concrete in a water bath for about three minutes. Moist concrete is easier to repair when you are using a concrete mixture. If the concrete is dry, it may absorb the water from the concrete mix and make the mix dry and difficult to work with.
Towel off the picnic table to remove any standing water or puddles, and allow the water to soak into the table for about two minutes. Apply the concrete mix to cracks in the surface of the picnic table with a putty knife. Force the mixture deep into the crack, and smooth over the surface to remove the excess concrete. Use a trowel or putty knife to apply the concrete mix onto both sides of a section that has broken off completely, and line up the seam to rejoin the two pieces together. Prop up the broken section with a support such as a rock or table, or try securing it in place with duct tape.
Cover the repaired area with a tarp or plastic sheeting, and allow the concrete mix to cure for at least 24 hours. Apply another layer of concrete repair to compensate for any shrinkage during the drying process. Repeat the application until the breakage appears seamless.