How to Paint Exterior Stone to Freshen Up Your House

Any dust, dirt, cobwebs, loose mortar or stone fragments, or other debris can prevent paint from bonding and sticking to the stone and mortar joints. Cleaning is essential for a solid paint job that sticks for many years to come. 

Use a garden hose with a spray nozzle to wet the stone and rinse away any loose dirt and debris. This will help keep your cleaning solution from soaking into the stone and mortar too quickly, allowing you to work with it long enough to thoroughly clean the wall before rinsing.

Scrub the stone with a stiff-bristled brush and a cleaner designed for masonry. Be sure to read and follow the manufacturer’s directions on the cleaning solution. 

Caution: We do not recommend using cleaners containing muriatic acid as the liquid and fumes can be harmful to you. Acidic cleaners may also harm nearby plants, whether the overspray from rinsing the stone or runoff that soaks into the ground near root systems. Additionally, we do not recommend using a power washer to clean the stone as it can be too strong and damage the stone and mortar joints.

Rinse the stone with the hose again and allow the stone and surrounding area to dry. It’s also important to let the stone dry thoroughly (anywhere from 2 to 6 hours, depending on the weather and direct sunlight) before applying any primer or paint.

While the stone continues drying, you can use a clean cloth to dry any windows, trim, soffit, or other materials adjacent to the stone you’ll be painting. 

Next, apply painter’s tape to the materials at the edge of the stone. Run a putty knife or something similarly flat over the tape to be sure the edges are sealed as well as possible to prevent paint from getting behind the tape. If using a putty knife is difficult because of the rough edges of the stone where it meets windows, siding, soffit, or other materials, pull a clean cloth over the end of your finger and run it along the edge of the tape to press it down completely. Make sure to remove any cloth fibers that may snag and stick to the edge of the stone. 

Lay down drop cloths under the area you’re painting to catch any drips. Be careful of draping painter’s plastic over roses or other plants that will be in the sun as you work. The greenhouse effect may overheat the plants and damage or kill them. If you must cover the plants to protect from cleaners or paint, remove the plastic as quickly as possible.

Pro Tip: It’s important to make sure that the stone does not have a sealer on it, which will prevent primer or paint from adhering to the stone and the mortar joints. If water readily absorbs into the stone and mortar, there is likely no sealer. If the water beads up, you’ll want to remove the sealer, which should be done by a professional.

Now that you’ve prepped the stone and surrounding area properly, you’re ready for the main event. It’s a good practice to apply primer made for masonry as it helps paint adhere and bond well to the stone surface. Apply one coat of masonry paint primer to the dry stone, using a 3-inch paint brush around the edges and a thicker-nap paint roller, from 3/4 inch to 1 1/2 inch, depending on how deep the texture of the wall is. If the mortar joints are very deep, you may need to paint those with a brush and then roll the face of the stone. Allow the primer to dry for the amount of time recommended by the manufacturer.

Stir the paint before pouring it into the paint tray. Put a paint tray liner into the tray and pour the paint into the tray.

As with the primer, paint the edges with a 3-inch paint brush and roll a coat of paint over the rest of the stone area.

Allow the paint to dry for the amount of time recommended by the manufacturer before adding another coat.

After the first coat of paint is dry, apply another coat. You should apply at least two coats of paint to ensure complete coverage. As one of the benefits of painting your home’s exterior, a solid paint job will help keep moisture out of the stone and mortar behind it. Moisture can cause the stone and mortar to deteriorate prematurely as well as cause the paint to blister and peel.

Carefully remove the painter’s tape, cutting the edges if necessary to keep from peeling any paint from the edges of your freshly painted stone. You’ll likely thank yourself for taking time and care during the prep phase, as it will make your cleanup much easier and faster. Make sure to properly dispose of paint you don’t plan to use. However, unused acrylic or latex paint can last anywhere from 2 to 10 years on average in the can if stored properly and not allowed to freeze.