Dirt Stains on Paint - Causes & Solutions

The uneven texture and grooves of brick, siding and other painted exterior surfaces make ideal places for dust, dirt and debris to collect, which dulls your paint and makes your painted items look dingy or mildewed. Find out more about the causes of dirt stains on paint and how to get rid of the problem.
 

Causes

The accumulation of dirt on the exterior of your home and other surfaces can stem from several sources. Leaking, full or missing gutters may allow dirty water from your roof to soil your siding, and mowing or weedwhacking can kick up dust and grass clippings that can cling to paint. Other environmental factors include deposits from pollution and exhaust, plus wind-blown particles. Using inappropriate paint can encourage dirt to cling to your surfaces, especially if it is low-quality, old or meant for interior use.
 

Solutions

First, you must ensure that the dirt clinging to your paint is actually dirt, and that you do not have a mildew problem. To test this, place a few drops of chlorine bleach on the stain. If the stain goes away, treat your staining as a mildew problem. If the stain remains, then you are probably dealing with the build-up of dirt and other particles. You can clean painted exterior surfaces by power-washing or rinsing with your regular garden hose. For stubborn stains, you can add a couple of teaspoons of trisodium phosphate, laundry detergent or dish detergent to a couple gallons of water, then apply this mixture with a mop or a sponge attached to an extendable handle. Clean the surface from the bottom up, and make sure to cover plants near the foundation as you wash. Thoroughly rinse the siding or brick when you finish scrubbing.
 

Prevention

Preventing the build-up of dirt and other particles must start with the proper paint for the surface on which it is used. High-quality latex paints specifically designed for exterior usage are the best products for preventing dirt build-up and staining. Prior to applying these paints, it is essential that the surface is cleaned and free from loose paint or other debris to ensure the paint adheres and cures properly. Fix leaky gutters and clean them regularly to prevent overflow, which can run down the outside wall of your house or splash the ground around the foundation. Hose off grass clippings or other clinging debris immediately to prevent staining, and clean exterior surfaces thoroughly at least once per year.

Dirt stains on exterior surfaces create a dingy, unsightly film that ages your home or furniture and dulls your paint job. By selecting high-quality latex paints and cleaning the painted surface regularly, you can enjoy years of lasting, fresh-looking color.

Primers and Finishes

Priming is essential for better adhesion, sheen uniformity, mildew control and durability. 
Select a top quality exterior paint in the color and sheen of your choice. 

Substrates, Primers

Substrate: Various 
Primer: Usually None 
Finish Coats: 1240 Acry-Shield Exterior Flat Finish 
1245 Acry-Velvet Ext. Low Sheen Finish 
1250 Acry-Lustre Ext. Semi-Gloss Finish 
1235 Seasons Ext. 100% Acrylic Flat 
1236 Seasons Ext. 100% Acrylic Low Sheen