Repairing a crumbling, broken or cracked concrete step is easy if you take these hints.
Concrete steps that are broken or crumbling are both unsightly and dangerous. Fortunately repairing them is fairly easy if you heed these few simple hints. Concrete can crack, crumble or be broken and although the repair techniques are similar, the preparation is slightly different. For any of these repairs, the tools required are simple.
The first step is to assess the problem. A common occurrence with steps is breaking or crumbling of the top outer edge (the nose) of the step. This can be caused by something striking the step or by concrete that did not set properly to yield maximum strength. Cracks in concrete are a normal occurrence with age or stress caused by shifting soil underneath. If the steps on one side of the crack seem to lean or be lower than those on the other side, then the foundation beneath the steps must be stabilized before repairs are made. If the steps continue to shift, the repairs will not hold.
If the repair is to a crumbling or broken step, then cleaning the site is next on the list of things to do. Use a hammer and chisel to remove any loose material. If you can remove it with a moderately hard hammer blow, then it will eventually fall off by itself. Work outward from the broken spot until you have hard, solid concrete on all sides. Sweep away all loose material and dust.
If the area to be repaired extends to the front edge of the step, you will have to build a form. This is just a flat board or piece of Masonite that is secured against the front of the step to prevent the concrete from running out of the repair area. It should be long enough to extend a few inches past either side of the repair area and be level with or just barely above the top of the step. You can hold it in place by propping sandbags or other heavy objects against it or by any other convenient method. It must be secure enough so that when the concrete is poured into the repair, it does not cause the form to move.
If you are repairing a crack that is less than ¼ inch wide, you should consider using a concrete crack sealing compound. This is a thick liquid (usually gray in color) that can be applied by squeezing it into the crack. It dries to form a seal that is weatherproof and flexible. If the crack is larger than this, then preparing the area involves using a hammer and chisel to increase the size of the crack to at least ½ inch wide and deep and removing all loose or crumbling concrete. Concrete does not stand up well if applied in thicknesses of less than ½ inch.
Now we're ready to begin the repair. There are concretes available that are specially formulated for patching. You can find them at hardware and builders supply houses. These special concretes can be applied in thin layers and will not crumble or break the way ordinary concrete will when used for repairs. Mix the concrete thoroughly until it is thin enough to pour but is not runny. You will need a trowel which is a square or pointed flat metal blade attached to a handle. These come in various sizes and shapes but for this project any one will do. For flat surfaces, you can even get by with a piece of 2x2 or 2x4 board. Now thoroughly wet down the concrete in and around the repair site.
For cracks, apply the concrete by pouring or with the trowel. Use the trowel to press it into the crack and remove the excess for a smooth surface. Wet the trowel and run it over the surface lightly to further smooth the surface. After an hour or so, you can go back with a brush or the trowel to achieve the surface texture you desire.
For other repairs, pour the concrete into the form until the repair area is full. Use the trowel to smooth the surface and remove the excess as we explained above. After 24 hours, you can remove the form and your repair should be complete. Try not to put too much stress on the repaired area for about a week until the concrete cures to its full strength.