Painted concrete decks and steps are not as popular today as just a few years ago. Many homes built a few decades ago often have painted concrete surfaces. Today, stained and other decorative techniques are common. Making over painted steps means stripping the paint off to expose the bare concrete. No doubt this is a challenging project unless using an effective method. While mechanically stripping off the paint with shot-blasters or grinders seems reasonable, these methods will easily cut into the concrete itself.
Another option to consider, that works remarkably well, is to use a liquid stripper to remove the paint. A couple of different options to choose from here are chemical strippers, or soy-based strippers. Chemical strippers are toxic, and safety measures must be closely followed when using them. Biobased soy products are nontoxic, more expensive and slightly less effective. The decision on which to use depends on the budget and the user's preference.
Use a high-pressure washer to clean the concrete steps. This will remove any loose paint from the steps and make stripping easier. Some of the paint will lift off from the jetted water. Allow the concrete steps to dry. Make sure to wear safety goggles or a face shield, no job is worth an injury.
Spread the liquid strippers on the top of a step. Paint strippers are in gel form and are easily spread with an old paint brush. Apply the stripper evenly over the area. Doing so will better ensure paint the paint lifts from the concrete surface evenly. Allow the stripper to set for several minutes before testing it.
Scrape a portion of the step with a stiff puddy knife. Observe how much of the paint is removed by applying a firm, steady, stroke. If a majority of the paint lifts easily, the paint stripper has set-up long enough. If the paint does not easily come up, let the stripper sit for several more minutes and check it again.
Remove as much paint from the top of the step as possible with the puddy knife. After removing all the loose paint, apply a second layer of stripper to remove any remaining paint. It's not uncommon to use two or three applications of paint stripper to remove all the paint. A lot depends on the paint, and the number of paint coats to take off.
Remove the paint in this same manner from the rest of the concrete steps. It's best to remove a single section of the steps at one time, instead of coating the entire area with stripper all at once. Stripper has a tendency to dry after an extended period of setting-up. Once dried, it can be somewhat harder to scrape off.
Use the pressure washer again to clean the concrete steps. This final cleaning will remove any remaining paint. The paint should come off much easier now, since it has reacted with the paint stripper. Once the steps have dried thoroughly, they are ready to be repainted, stained, are whatever the home improvement project calls for.
Concrete is porous, and will still be damp when it first appears dry. Allow plenty of drying time between steps
Wear chemical goggles and gloves when using a chemical stripper. Protect areas around the steps with plastic sheeting to prevent stripper from damaging these areas.