Alongside its roof, foundation and gutter system, your home or commercial property’s siding has the important job of repelling precipitation. It prevents rain and meltwater from saturating the insulation and rendering it less effective. It also prevents moisture from infiltrating the frame where it can create the ideal breeding ground for black mold.

But preventing leaks isn’t your siding’s only important job. When it leaks, siding also provides easy access to pests like carpenter ants and paper wasps. Even if it didn’t allow water to soak the underlying insulation, cracked siding would still impact a home’s ability to retain heat. Finally, cracked or otherwise damaged siding is not easy on the eyes. Keeping its siding intact is essential to preserving a building’s curb appeal and market value!

In effect, by detecting leaky siding you are not just taking steps to prevent harmful water infiltration. You are also keeping it safe from insects, heat loss and devaluation. What’s more, the sooner you detect leaky siding, the less you will probably have to pay for its repair.

That is all to say that you have a lot to gain by noticing the five signs of leaky siding. Let’s review them now so you know what to look for!


Stained or Streaky Siding

The wood in your home’s frame contains tannins – perfectly natural chemicals that are found in tree sap. When water infiltrates siding, the tannins in the underlying wood can bleed out and stain the exterior. Tannin staining is unsightly, but at least that draws your attention to an obvious sign of leaky siding.

Have you noticed greenish, brownish or other dark-colored stains on your siding? They are probably algae. The microorganisms don’t always indicate the presence of a leak, but their stains warrant thorough investigation by an exterior contractor all the same – especially if those stains manifest themselves around the siding’s seams.


Interior Wall Discoloration

Interior walls can become stained for a number of reasons, one of them being mold growth. Mold cannot grow without a sufficient supply of moisture, which is why mold-stained walls may indicate that a leak in the roof or siding is allowing moisture to seep through the exterior.


Peeling Paint or Wallpaper

Once water saturates wood or plaster, it can sufficiently weaken the surface until paint no longer adheres to it. Leaky plumbing and excessive indoor humidity can both cause paint to peel, although leaky siding and roofing are both common culprits as well. Wet walls (or extremely dry or humid indoor air) can also weaken wallpaper glue until strips begin to curl off the wall.


Musty Odor

We have already pointed out that mold thrives in the damp environments created by leaky siding. Mold isn’t always readily visible, but it can also reveal its presence thanks to its oftentimes strong odor.

As a fungus, mold reproduces by releasing tiny spores into the air. Spore release is typically accompanied by the concurrent production of microbial volatile organic compounds (MVOCs). Many MVOCs are odorless, although they can contain musty-smelling mycotoxins. People often liken the odor of mycotoxin to that of cat urine, mowed grass, cooked fat, cigarette smoke, dirty socks, old cheese, and even maple syrup. If you note a distinctive and otherwise inexplicable odor in your home, you may be detecting mold growth that has resulted from leaky siding!


Damaged Siding

Let’s finish off with the most obvious sign of leaky siding: siding which is visibly damaged. If you notice that your siding has cracks, dings, dents or large gaps in its seams, then your home’s exterior is either (A) no longer effectively repelling moisture, or (B) at risk of no longer doing the same.



If you have noticed any signs of leaky siding in your home, then you can minimize further damage to your property and save money on necessary repairs by taking immediate action. If your property is located in the greater St Cloud, Little Falls, Alexandria or Brainerd, MN areas, then we welcome you to contact Exterior Pro today to request your free estimate!