Siding is meant to protect the walls of your home from moisture. If the siding fails, moisture gets into the walls where it can cause rot, mildew, and other severe structural issues.
1. Interior Wall Damage
Often, the first sign of an issue with exterior siding is interior damage on walls that have extended to the sided exterior. You may notice water stains and discoloration on the walls, or the paint may begin to bubble and peel due to the moisture seeping through the wallboard. Drywall and plaster will also become soft, while wallpaper may start to peel and paneling may warp.
2. Mildewed Siding
Black or dark green speckles on siding typically means moisture is behind the panels. Mildew can affect any type of siding, from wood to vinyl, although all but wood can be cleaned easily. Cleaning isn't enough, though. It's important to verify that the mildew-causing moisture is only on the exterior of the siding and not a result of moisture that has leaked behind it and into the walls.
3. Soft Siding Boards
Wood siding, which includes everything from wood lap panels to shake or shingle siding, can rot if moisture is getting behind the siding. Rotten wood will eventually swell and deteriorate, but you can spot rot earlier by placing a bit of targeted pressure on the siding. If a fingernail or screwdriver head easily sinks into the wood, then there is a high likelihood that rot has occurred. Rot can't be reversed, so you must install new siding in order to fix the problem.
4. Warped Siding Panels
Warping is most common with wood siding panels that have absorbed moisture and will soon begin rotting. The panels will no longer lay flat and they may develop a rippled appearance. Vinyl panels can also warp, either due to installation issues or because of heat exposure. Once warped, moisture can easily seep behind them. Warped siding must always be checked out by a siding service to determine if the problem can be repaired or if new siding is needed.
5. Basement Water Stains
In homes with a basement, leaking siding issues may first become obvious along the tops of basement walls. You may notice wet stains where water is seeping into the top of the wall, or a chalky white efflorescence may form on the walls.
Contact a siding service if you suspect that you have damaged siding that needs to be repaired or replaced.