Perhaps when you were doing your fall outdoor maintenance you noticed your siding had some stains, and you made a mental note to deal with it come spring.  But in order to take care of the problem, you need to understand the cause.

What Are the Causes of Siding Stains? 12dec29c3a134Generally, stains that look like drips originated as moisture. There are other types of stains, such as algae or mold, but the ones that appear as a darkened teardrop are water-based. The cause could be ice dams, high humidity, or leaky rain gutters. The water can leak through the wood, carrying tannins to the surface of the siding as it finds its way out.

An ice dam is a build-up of ice starting at the edge of the roof, which holds back water from melting snow. When the water builds up on the roof, it leaks through the shingles and wood below. These stains generally start near the top of the walls and run down.  Eventually it can lead to roof leaks and wet ceilings. Ice building up along the gutters (icicles) is a sure sign of ice dam problems. The prevention of future ice dams will take care of this. A contractor will provide the path to take, as there are a few different reasons these take place.

Randomly located stain spots on a wall are most likely an indication of humidity issues. When certain conditions arise, the wood behind the siding can become saturated, with built-up moisture leaking out through the siding. During very cold weather, humidity can migrate through a wall, condense into water droplets, and freeze. The freezing expands the water, pushing it out through the exterior of the home. The more humid the conditions are inside the home, the higher the propensity for these stains. Home humidifiers can be used in the winter to alleviate the effects of dry heat, but these can contribute to excessive humidity issues. (If you use an indoor humidifier, choose one with a sensor that will shut it off when it reaches the desired level. It should be set for under 45%; the lower the better, but set according to your comfort level.) Kitchen and bathrooms should have properly working exhaust fans. Good ventilation should exist in any attic areas. Crawl spaces should have vapor barriers installed. Sealing up homes against air infiltration is generally an energy savings tool. This, however, can lead to humidity issues if overdone. Air drawn in a home that is either heated or cooled also needs a path of escape. The correct path should not be in tiny cracks and crevices to the exterior of the home. A proper ventilation system provides for this.

Of course, there are a variety of other causes of siding stains, such as mold and mildew, bird droppings, tree sap, etc., but the most common ones are caused by moisture, especially ice dams.  Make sure your siding is in great shape - don't ignore those stains, because they could be an indication that you've got a problem that's much more than cosmetic.  It's especially important to take care of ice dams.  When you call us here at Quarve, not only can we remove the ice dams for good, but we can ensure that your siding is in good working condition.  We are a licensed exterior home improvement contractor for the St. Paul and Minneapolis area, and we offer siding, roofing, gutters, and replacement doors and windows.