What kind of paint do you use to paint an outdoor concrete statue?

If you think you might have a moisture problem, now is the time to address it. Place a section of clear plastic on the cement and tape the edges down, but not so tight as to be laying tightly on the cement, and wait overnight. If there is water on the cement, then you have water coming up through the cement, and I would suggest that you not paint your patio at this time. If there is water on the plastic side, then it is just condensation and you should be ok.

First, you need to make sure that it is clean of all mold, mildew and debris. I would suggest using a mixture of 15% bleach to water for the moldy areas. Spray that on and let it kill the mold for a few minutes and then pressure wash to whole patio. Remember, it's always worth it to get it done right the first time.

Next, you will need to acid etch it if it is smooth. If it is rough, then you can skip this part. Mix one part muriatic acid (found in most large hardware stores in the pool supplies section) to 8 parts water. Use goggles, and wear long pants. Wash off your skin immediately if you get some on there. Pour the acid mix on the cement (I usually use a plastic watering can). Use a broom to get the acid mix to all the areas. Depending on the size, you might need to mix a few cans. Don't skimp on getting the mixture spread.

(Quick side note - Don't let this mix get on anything you don't want ecthed. If it is adjacent to other cement, wet the other cement well with plain water, and keep it wet with plain water while you etch near that section. Excessive water will dilute the mix and keep your other cement from discoloring ... but don't get the water on the area you want to etch.)

Once the mixture is spread and has quit smoking, rinse it off with LOTS of water.

Wait till the next day for it to dry.

Take a leaf blower and a broom and remove any sandy residue caused by the etching.

Make sure that you apply a product that is meant for exterior patio areas. H&C makes a decent product that can last for years with proper care and can be found in most large hardware stores.

Your cement patio should be clean and dry at this this time.

Use a paint brush to paint around the area first, including around colums and any difficult to reach areas (this might include the vertical step if you so desire). Next, use a roller to roll on a coat. Let this dry for a few hours and then apply a second coat. Two coats are usually sufficive, but you might need a third. Don't put anything on your porch for at least 24 hours to ensure proper curing time.