How to Prepare Exterior Brick for Painting? | The Right Way

Getting a smooth, lasting finish on exterior brick starts long before the paint roller comes out. The work is in the prep: removing dirt and chalky deposits, fixing cracks and mortar joints, and giving the wall time to dry completely. Skip any of these steps and you risk bubbling, peeling, and a paint job that fails within a season. Here’s the sequence that works, based on guidance from Sherwin-Williams and the brick industry’s own resource, GoBrick.

Clean The Brick Thoroughly

Start by sweeping away loose debris, cobwebs, and dust with a stiff brush. For deeper grime, mildew, and efflorescence — that white, chalky salt deposit that forms on brick — scrubbing with a heavy-duty soap and water is the first move.

Pressure washing works well for exterior brick when done carefully. The best exterior brick paints will fail if the surface underneath is dirty, so this step matters. Keep the pressure around 1500–2000 psi and hold the nozzle at an angle to avoid driving water into the wall. One DIY guide recommends using the lowest setting on the washer to avoid etching or damaging the brick face.

After washing, the wall needs time to dry out completely. Painting damp brick is one of the most common mistakes — trapped moisture leads to bubbling, peeling, and premature failure.

Repair Cracks, Holes, And Mortar Joints

Once the wall is clean and dry, inspect it for chips, holes, cracks, and loose or crumbling mortar. Small blemishes can be patched with a paintable, watertight mortar patch caulk, like White Lightning Mortar Patch Latex Caulk. For larger damage, fill and smooth the area with a masonry-compatible patching material before priming.

Loose or missing mortar should be repointed before any coating goes on. This means removing the deteriorated mortar and packing fresh mortar into the joints. If you skip this step, moisture can get behind the paint and cause it to blister and fail. Allow any patching material to cure fully according to the manufacturer’s instructions before moving on.

Check the surrounding area too. Protect windows, fixtures, plants, and the ground from paint splatter and pressure-washer overspray with drop cloths and tape.

Apply A Masonry Primer, Then Breathable Paint

Primer is non-negotiable for brick. A masonry-specific or alkali-resistant primer, like Sherwin-Williams Loxon, seals the porous surface and helps the finish coat bond. It also blocks the salts in brick from bleeding through the paint later.

For the finish, use a breathable, vapor-permeable exterior masonry paint. This lets the wall release moisture instead of trapping it, which is what causes paint to peel on brick.

When Should You Not Paint Brick?

New brick needs time to cure before it takes any coating. The safest route is to defer painting new masonry for as long as your timeline allows.

If the brick has active moisture problems — leaks, rising damp, or visible water stains — those need to be fixed before painting. Sealing wet brick traps the moisture inside and makes the damage worse. The wall needs to be structurally sound and dry before any primer or paint goes on.