Most homeowners don’t realize their windows are failing until a pane falls out or a draft becomes too bad to bear. Wood rot is often termed as the “silent killer” when it comes to curb appeal and energy efficiency, and it is important to note that wood rot can be concealed beneath a fresh coat of paint, and therefore, the exterior of your windows might look new and updated, while the wood underneath is slowly turning into mulch.
At Rotten Window Repair, we specialize in the methods used to uncover hidden decay and have developed a particular method called “surgical” restoration; this type of restoration will uncover hidden decayed areas of your windows before they require a complete (and often expensive) replacement. Below are five indications that your windows have decayed from within.
1. The “Soft Spot” Mystery (The Screwdriver Test)
A “soft spot” can often be found near a window’s bottom corner; this area appears to be a little wavy under its paint layer. This occurs when moisture gets trapped between a wood surface’s upper paint film and the wood fibers, thereby damaging the wood’s surface in the area that moisture has gotten trapped, but the paint above remains intact.
Pro-Tip: Use a small screwdriver, awl, or pocketknife to press into the wood at the joints of a window. If the tool easily sinks in as if you are pressing into butter or balsa wood, the wood is decayed from within. The wood should feel solid; therefore, you should provide pressure against the surface and the tool should remain firm.

2. Persistent Condensation Between the Panes
Do you see fog or moisture droplets trapped inside the double-glazing that you can’t wipe away? This indicates that the seal of the unit has failed. If condensation remains in the space, moisture will remain and cause accelerated internal deterioration in the wood of the window frame.
Our Solution: If your double-glazing is cloudy, we will replace the glazing with high-quality Cardinal glass (with a warranty of 20 years) instead of having to replace the entire window, and you will save thousands of dollars.

3. Difficulty Opening or Closing
If you have to use a lot of effort to get the window to open up or it feels “spongy” when you go to lock the window, then it’s time to take a closer look. When wood rots, it absorbs moisture, expands, and thereby causes a change in the structure of the window which will cause the window to no longer operate; if the window used to slide, and now it is difficult to slide, it is very likely that the wood framing around the window is swollen from moisture and leading to a structural rot.

4. Flaking, Cracking, or Bubbling Paint
Paint is the skin of your window. Once you get very fine cracks and splits in the paint, especially where two boards come together, moisture can be drawn to the wood through capillary action and other means.
Bubbling paint indicates that moisture is “exhaling” out of the wood to be released as air. Do not just paint the wood over again after you see this; painting over wood that has already rotted away will just help the problem worsen, as the wood decay will continue to grow under the new paint.

5. Discolored Interior Trim or Drywall
If you see yellowish or brownish stains on the wall under the window or on the wooden interior casings, that isn’t good news. If you can see staining on the inside of the window, you can be assured that the exterior of the window is probably already severely compromised because of the substantial amount of water that has already moved through the entire thickness of the window unit.

Why Act Now?
The Cost of Delaying Repairs
Almost always, small issues grow into big issues. Ignoring these signs can lead to:
- Higher energy bills due to air leaks;
- Mold growth and moisture damage inside your walls;
- The spread of wood rot to the structural studs of your home;
- More expensive repairs or full glass failure later.
Conclusion
It’s great when every detail in your home works properly, but to achieve this, you need to pay a little attention to it regularly, check it for integrity and serviceability, and fix minor problems before they turn into major ones. Don’t worry, the Rotten Window Repair team is always ready to lend a hand in caring for your windows. Feel free to ask any questions you may have by calling +1 (630) 716-6181 or filling out the special form on our website (attach photos of your windows, and we will call you back and schedule a free window assessment).