Patching crumbling concrete steps enhances the appearance and safety of your home, all for a fraction of the cost of new stairs. And the best part is that it's a task that most do-it-yourselfers can handle with ease.
As the weakest point of construction, the step's edge is most vulnerable to damage. Expansive soil, freeze and thaw cycles, efflorescence, and deterioration from salt and disruptive traffic are a few of the major causes of crumbling concrete stairs.
Crumbling steps frequently result from what were once small cracks that were not tended to. A majority of the damage to steps can be prevented by caulking, which allows the concrete to expand and contract yet prevents moisture from entering the area.
Isn't it just like a home fix-it expert to suggest breaking it the rest of the way as the first step in making a repair? To repair a concrete stair -- or anything else made of concrete -- you must first completely remove all loose pieces and make sure that what remains is solid.
Start the repair process by removing the loose and crumbling concrete with a sledgehammer and cold chisel. Be sure to wear safety goggles. Sweep up all of the debris and clean the area with the strong spray of a garden hose.
After you have a clean, solid foundation, assemble the following:
- 1 mixing container
- 1 shovel
- 1 garden hose
- 1 concrete finishing trowel
- 1 wooden float (a wooden trowel used to tamp and work the concrete into place)
- 1 small piece of 3/4 quarter-inch plywood to act as a form board (scrap pieces of plywood can be obtained from most home centers or lumber yards)
- Concrete bonding agent
- Ready-to-mix concrete patch material (or epoxy patch material)
- 1 tarp or plastic sheeting
- 1 quart of clean motor oil or concrete form release oil
- At least 4 bricks (more may be needed)
Follow these steps to get your steps feet-worthy:
- Paint the raw patch area with a concrete bonding agent.
The bonding agent is a glue that helps the new patch material adhere to the old cured concrete. Allow it to set up for about 15 minutes before installing the patch material.
- Use a circular or hand saw to cut the scrap piece of plywood to act as the form board that will be set flush against the face of the step to hold the concrete patch material into place until it is fully cured.
The form board should be cut equal to the height of the step and a few inches longer at either end than the damaged area.
- Apply a light coat of clean motor oil or form release oil on the surface of the form board facing the concrete to prevent the form from sticking and damaging the patch when removed.
- Place the form flush against the face of the steps for a smooth patch.
The bottom of the form board should fit flat against the top of the step below.
- Use several bricks to hold the form boards firmly in place.
- Mix the concrete patch material.
Vinyl concrete patch or polymer cement are the most popular concrete patching products because they are easy to use and blend well with the old material. Though more expensive, epoxy patch material is the best money can buy. It is stronger and holds better -- the result of a chemical reaction among the ingredients of the adhesive.
Pack the material into the area with a wood float. The butt end of the float works great for this. The consistency of the patch material should be loose, but not runny. The material must be firmly packed into the orifice, eliminating any air pockets for a solid connection.
- Remove excess patch material with a wooden float and finish the patch to match the surrounding concrete with a metal concrete trowel.
- When the material starts to set up (in approximately 10 to 30 minutes), cover it with a tarp or sheet of plastic.
Doing so holds moisture in. If the material dries too fast, it may crack or not adhere securely.
- Until the concrete has completely dried (which could take up to a week), remove the cover once a day and spray the patch with a fine mist of water. Then replace the cover.
Leave the form board in place during the drying process to reduce the prospect of damage resulting from form removal or foot traffic. Complete the job by carefully removing the form boards, stakes, and bricks.
Most exterior concrete surfaces have a slightly rough finish to prevent slipping when wet. The most common finish is the broom finish. After the concrete has had a chance to become firm, it is brushed with a broom. A similar look can be achieved for a small patch by using a stiff paintbrush instead of a broom.