As expert siding contractors in Colorado Springs, we know exactly what it takes to keep your house siding beautiful and in good repair. No homeowner wants to spend time, effort, and money on siding repairs or new siding installation only to discover unsightly discolorations on their home’s exterior.

Many homeowners are perplexed by these stains, which can seem to appear overnight. It’s hard to know what to do about a stain; it’s not exactly damage, but then it’s not exactly something you want to live with either.

Below, we discuss some of the most common causes of house siding stains, as well as the best way to treat them so that you can enjoy a home that’s beautiful outside and within.

Identifying House Siding Stains By Color

It’s true! The color of the stain is your first and biggest clue about what is causing the problem. Are you doing regular visual inspections of your home and siding? Walking around the entire perimeter at least once a month can help you catch these minor problems before they become major issues.

Here’s a quick color-coded guide to some of the most common house siding stains:


These stains often appear like long streaks running vertically down the side of your house. Brown stains are most likely the work of rusty nails in your house siding, but if you have cedar wood siding, it could also be a sign of water damage.


These stains often appear on house siding horizontally and in large patches. Black stains are most likely a sign of algae, mold, or other fungal growth. However, if you have a wood or coal burning fireplace, it could also be the result of settling soot.


These stains often appear as a sign of algae or moss growth. Is your house located very close to another house, building, or barrier of some kind? It may be that partial sunlight plus a lack of ventilation is allowing this growth to continue.


These stains often appear because water is causing deterioration of the sheathing or insulation that lies behind your house siding.

Most of these stains can be cleared up by washing your house siding with a solution of sodium hypochlorite (household bleach) and warm water. However, if you suspect that the stain is the result of water damage, it’s important to contact DJK Siding and Construction in Colorado Springs for a siding inspection right away.