Concrete has a well-deserved reputation as one of the hardest and most durable building materials on the planet. Yet that doesn’t mean that concrete has no Achilles’ heels of its own. On the contrary, as time goes on, concrete may fall victim to a wide variety of problems. So-called spalling represents one the most common problems.
Fortunately, you can restore the appearance and structural integrity of spalled concrete through the procedure known as an overlay. If you would like to educate yourself about this vital concrete restoration technique, read on. This article will discuss the issues posed by spalling, and outline how an overlay can help to eliminate the problem.
Whether you realize it or not, you have likely encountered spalled concrete on many occasions. This unwelcome phenomenon involves the outer surface of the concrete cracking, crumbling, and flaking away. Spalling leaves behind craters and pits that destroy not only the visual appeal of the concrete but also represent a potential tripping hazard.
Spalling occurs as the result of stresses imposed on the concrete by the environment. Water tends to be a significant factor. The more time water spends on the surface of your concrete, the greater its destructive effects will be. Those who live in areas where winter temperatures regularly dip below freezing must be especially careful, as the freeze/thaw cycle will promote more rapid spalling.
Regardless of how your concrete became spalled, you must be proactive about having it repaired. Otherwise, the problem will only escalate, as the missing patches of concrete will allow greater amounts of water to accumulate. A concrete overlay effectively eliminates the problem by filling in the missing areas, leading to an entirely new – and entirely level – top layer of concrete.
The depth of a concrete overlay may vary, with most being between 1/8″ and ½” deep. Generally speaking, the more traffic the concrete sees, the thicker the overlay should be. This will increase its effectiveness at resisting pressure-related damage – say, from heavy vehicles. For sidewalks and other residential purposes, a thinner overlay should work just fine.
Installing Concrete Overlay
A concrete overlay should only be installed by a professional with the requisite knowledge and experience to do the job right. However, you will be able to help by preparing the damaged surface. Thoroughly remove any bits of broken concrete, then give the area a good washing to remove any dirt or debris – preferably with a pressure washer.
Overlay installation proceeds similarly to that used in installing a new concrete surface. First, the contractor sets up wooden forms around the outside of the slab. These forms will act to contain the overlay, preventing it from overflowing from the designated area.
The wooden forms used in installing a concrete slab must be quite thick and sturdy, in order to resist the substantial weight of all that wet concrete. Because an overlay is many times thinner, however, the forms used here do not have to be quite as hardy. Contractors can often get perfectly good results using strips of plywood furring.
Once they have mounted all of the forms, the contractor will mix up a special combination of water, sand, and cement. This mixture will help to promote a strong bond between the overlay and the existing concrete when applied the spalled patches with a paintbrush. Think of it as the primer that painters apply to a wall before laying down the top coat.
Finally, the pre-mixed concrete overlay will be carefully poured out into the forms. Workers then level the surface with a bull float. If desired, they will also add surface texture using the tool known as a concrete broom. After a couple of days of curing, the overlay should be good to go.
Concrete Repair Experts
If you’ve got damaged concrete on your property, don’t worry. A good chance exists that a trained professional can repair it. For more information, please don’t hesitate to contact the experts at Harding Group.