Gentle is the whole method
Stone veneer looks tough, but it is a thin layer attached to a wall, not a solid stone structure. The safe way to clean it is to wet it, apply a mild, stone-safe detergent, let it dwell, scrub stubborn spots with a soft or medium nylon brush, and rinse with low pressure from the top down. High pressure aimed straight at the joints is the most common way people damage it.
Ledgestone, the stacked style with thin horizontal pieces and deep shadow lines, needs extra care. Those deep gaps trap dust and spider webs, and a strong jet can blow out mortar or force water behind the pieces.
Manufactured or natural? Why it matters
Most stone veneer on LA homes built or remodeled in recent decades is manufactured stone. It is cast concrete with color pigment, shaped to look like real stone. The color is in the mix and on the surface, and an aggressive tip can wear the surface and make it look blotchy or faded.
Natural thin veneer is real stone cut thin. It may be sandstone, limestone, slate or quartzite, and each reacts differently. Limestone and some sandstones react with acids, so vinegar and acidic cleaners can etch them. If you are not sure what you have, check the back of a loose or spare piece, look for repeating shapes, which usually mean manufactured stone, or ask the installer. When in doubt, treat it as the more delicate option.
Step by step
Start by brushing or blowing out loose dirt and webs from the joints. Pre-wet the wall and any plants below it, so the cleaning solution does not soak deep into dry stone or burn leaves. Apply a pH-neutral or mild alkaline cleaner made for masonry, and keep it wet while it works. Work small sections so nothing dries on the surface.
Rinse with a wide fan tip held well back from the surface, angling the spray down so water runs off rather than into the joints. Work from the top down, and finish by rinsing the ground below so dirty water does not leave a ring on your walkway.
Timing helps. On a hot Valley afternoon, cleaner can dry on sun-facing stone before it does its job and leave streaks. Morning or a cooler, overcast day gives you more working time. If the wall faces a pool or a patio you just cleaned, cover it or plan to rinse it again at the end.
White haze and efflorescence
A chalky white bloom on veneer is usually efflorescence, salts carried out of the masonry by moisture and left behind when the water evaporates. It shows up most where sprinklers hit the wall or water collects at the base. Dry brushing often removes light bloom. Heavier deposits may need a cleaner made for efflorescence, used carefully and tested first, especially on natural stone that reacts with acid.
Cleaning removes the white residue, but it will come back if water keeps getting into the wall. Redirect sprinklers and fix drainage first. Our efflorescence guide covers the causes in more detail.
Should you seal it?
Sealing is optional. A breathable, penetrating sealer made for masonry can make future cleaning easier and slow staining. A film-forming sealer that traps moisture can cause flaking or darkening on veneer, which is hard to undo. Many manufactured stone makers give specific guidance on sealing, so check it before you buy anything.
If you do seal, the wall must be clean and fully dry first. In LA, that usually means waiting for a dry stretch outside the November to March rainy season.
When cleaning is not the fix
Some problems are repair work, not washing. Loose or cracked pieces, crumbling or missing mortar, rust-colored streaks from metal flashing, and staining that comes from behind the veneer all point to moisture or installation issues. Washing a wall with open joints can push more water behind it. Get those fixed by a mason first, then clean.
When Say Wash It cleans a house with stone accents, we treat the veneer as its own zone: lower pressure, more dwell time and more brushing than the stucco next to it. Stone veneer is usually part of a house wash, which is $0.35 per square foot of exterior wall as of October 2026, and the instant quote on this page can include it.
Key points
Gentle is the whole method
Stone veneer looks tough, but it is a thin layer attached to a wall, not a solid stone structure. The safe way to clean it is to wet it, apply a mild, stone-safe detergent, let it dwell, scrub stubborn spots with a soft or medium nylon brush, and rinse with low pressure from the top down. High pressure aimed straight at the joints is the most common way people damage it.
Manufactured or natural? Why it matters
Most stone veneer on LA homes built or remodeled in recent decades is manufactured stone. It is cast concrete with color pigment, shaped to look like real stone. The color is in the mix and on the surface, and an aggressive tip can wear the surface and make it look blotchy or faded.