Repair a Concrete Step
Not only is a flaking, crumbling, or cracked concrete step unsightly, it can also be a dangerous trip hazard. When the combination of years and weather elements begin to take a toll on your concrete steps, you need a way to repair them quickly, safely and economically. Fortunately, this is a project that you can do on your own with too much mess and without a great deal of expense.
If the horizontal surface of your concrete step is flaking or chipping away, then you may just need to resurface it. There are several good products on the market that you can use to accomplish this task. A vinyl concrete patch is perhaps the easiest. This material mixes up easily and, instead of spot patching as you would with regular concrete patch, this material is spread over the larger surface of the step. It flows into the chips and pits left behind by the flaking concrete. This material is thin enough to find its own level, so you just need to spread it around and make sure that it is smooth. As with any masonry work, it is important to make sure that the area is clean of debris, dust, and broken pieces of concrete before you apply it.
Another scenario involves a concrete step where the corner of the step has cracked and broken off, leaving a dangerous and jagged edge. If this is the case, then you will need to build a small form to hold the concrete patch into place. In most instances, this form is easily built using 2x6's and some screws. Remember, a form doesn't have to be built to long-term construction standards; it just needs to hold the concrete in place until it sets up. Make sure that your form can be easily disassembled and that you won't have to damage your new patchwork when you are trying to take it apart.
The best product to use for repairs like this depends on the size of the damage. If the corner or edge that you are repairing is small and no more that 2" deep, then you can use sand mix. Sand mix is a dry mixture of fine sand and Portland cement. It is used to make shallow repairs because it doesn't have any stone. The lack of stone allows you to float the wet sand mix to a smooth finish that will blend in well with the rest of the step. If the repair that you need to make is deeper than 2", then you should use a standard ready-mix concrete. This does have stone in it. You need to use this stone mixture on deeper patches because the stone gives additional strength to the concrete after it has dried. If you tried to use the sand mix to patch the deep spots, it would crumble and break away when it became exposed to regular traffic.
A third scenario involves a crack in the middle of the step or walkway. There is no concrete flaking or breaking away, the slab has simply broken in two, and now there is a gap. There are several reasons why you need to fix this quickly.
First, it will just continue to get worse. If you live in a part of the country where you have a seasonal freeze and thaw, then the action of the ground flexing will continue to pull the broken pad apart. Secondly, you need to fix it quickly because this is a serious safety hazard. Whether you have small children or elderly women whose heels may get caught in the crack, a hard fall on concrete can be devastating.
The ideal way to fix this depends on the nature of the crack. If the two pieces are still level with one another, then begin by stuffing a piece of backer rod into the crack. Backer rod is a foam rope that can be purchased at your local home improvement store. When you shove it into the crack, it expands and creates a surface for your patch material to sit on. Without the backer rod, the patch would just flow into the ground underneath the step. Once the backer is in place, use a polyurethane concrete patch to fill the crack. This is rubberized filler that will flex with the seasonal changes and won't pull away and crack further as a concrete patch would.
If the two pieces are not level, then you need to form a ramp of sorts to smooth the transition from one piece to the other. This difference in height is what will cause most falls. The best way to form this transition is to use backer rod to fill the majority of the crack and then use sand mix like we discussed above. Using a trowel, fill the remainder of the crack with sand mix and then let it dry. After the sand mix in the crack has dried, use a second application to form a transition between the two different heights of concrete. It should be gradual, so that people can slide their feet over it without stubbing a toe or a heel. Remember, the idea is not just to fill the crack, but to make the walking surface safe.
Any tools that you use when working with concrete should be cleaned immediately. Most will clean up quite well just with the garden hose and some fresh water. Any product that you use that requires more than water will give detailed clean up instructions on the package. Remember, it is easier to take a few extra minutes to clean up your tools quickly than it is to try to chip away dried up concrete the next time you want to use them.