Mud Splash Along the Bottom of Siding

Why it forms a band

Splash has a limited height, so the soiling stops at a consistent line rather than fading gradually. The band is highest where water falls hardest, which is under roof edges with no gutter, at downspout discharge points, and where an eave gap concentrates runoff. That pattern is diagnostic.

Why it is worse on some walls

Bare soil, bark mulch and fine gravel splash readily. Lawn, dense planting and coarse rock do not. Walls facing prevailing weather take more rain and therefore more splash. Where a downspout dumps at grade without an extension, the wall beside it gets years of concentrated splashing.

Cleaning it is easy, keeping it clean is landscaping

Soft washing at $0.18 per square foot removes it readily, since it is surface soil rather than bonded staining. It also returns with the next wet season unless the source changes. Downspout extensions, a gravel or planted border, and correcting grade that slopes toward the wall all reduce it substantially.

Watch for what the splash is telling you

Persistent splash at one point usually means water is being concentrated there, and water concentrated against a foundation is worth looking at for reasons beyond appearance. A downspout discharging at the base of a wall is a drainage issue first and a cleaning issue second.