1. Latex-painted interior walls
Cleaning walls depends on whether the paint is oil-based or latex, says Will Bias, owner of MB Painting and Maintenance Services, LLC, in New Orleans. To safely clean latex-painted interior walls, mix three or four drops of dish detergent in a half-filled bucket of water. You can also go old school and combine two or three tablespoons of distilled white vinegar to a gallon water.
Then, wet a sponge in the mixture and wring it out dry. This is especially important as you don't want to mess up your walls with lines of dripping water. Wipe off the dirt, rinse the sponge, and repeat as needed. This works for all types of latex paint be it flat, semi-gloss or gloss. Just make sure the sponge is completely wrung out before cleaning around electrical outlets, light switches, and telephone connections. In addition, before cleaning dirty outlet covers, turn off the electricity to those areas first to avoid shocks. If marks don't come off using soap and water, or white vinegar and water, you'll have to repaint.
2. Oil-based painted interior walls
Oil paints tend to be a bit hardier. So, in addition to cleaning with the detergent/vinegar and water mixture, you can use a mild degreaser to remove grease, especially on kitchen walls. However, do ensure that it is a mild degreaser and follow package directions carefully. As with latex-painted walls, don't use a scrubby sponge, Teflon pad or harsh chemicals to clean the walls. If you do, you will leave a permanent streak mark everywhere you wipe. Once again, follow the precautions above when cleaning around electrical and phone outlets.
3. Exterior walls
Whether latex or oil-based, to clean exterior walls, start by wetting the walls and using a pump garden sprayer, lightly spray the walls with a mixture of half-cup Jomax, one cup bleach and enough water to fill the container. Next, allow the mixture to set for 15 minutes, then scrub with a soft scrubbing brush. This will remove the mildew, mold and other dirt. Rinse with a garden hose. If cleaning a two-story house, a garden hose may not reach high enough to completely rinse the walls, so you can use a pressure washer if it fits with a 25-degree nozzle. Just spray the water as it comes out. Be careful though, as using pressure could damage the paint, cutting into the siding.
Maintain a freshly painted look on your walls by keeping them free of dust and spots. Preventative maintenance also means less scrubbing time later. You could vacuum walls with a soft brush attachment then wipe them down with a cloth-covered broom or mop and spray with a dusting agent for best results, or use an electrostatic dusting wipe. Just be sure to wipe away fingerprints and other marks soon after they appear and avoid using an excessive amount of water.
Recipe for All-Purpose Detergent Solution
Combine 1 teaspoon of liquid dish detergent into a quart of warm water, then add 1/4 teaspoon of white vinegar and let the solution sit on the stain for 10 minutes before blotting.