The short answer
Common Causes of Bottom Rot
Water is the main culprit. When rain hits the driveway, it splashes up and soaks the bottom edge of the door. If the rubber seal along the bottom is cracked or missing, water seeps into the wood or the metal's inner layer. Over time, that moisture breaks down the material, causing rot, swelling, or rust.
Another cause is poor drainage. If the ground slopes toward the garage, water pools at the base of the door. Sprinklers aimed at the garage, or a downspout that empties near the door, can also keep that area wet. Even condensation from a hot, humid day can add moisture if the door is not sealed well.
- Cracked or missing bottom seal
- Driveway sloping toward the garage
- Sprinklers or downspouts soaking the door
- Standing water after heavy rain
- Poor paint or finish that lets water penetrate
How Water Damage Progresses
Rot does not happen overnight. It starts with a small spot where the finish wears thin. Water soaks in, and the wood begins to swell or the metal starts to corrode. You might notice peeling paint, a soft spot, or a darker line along the bottom. If you ignore it, the damage spreads upward and can weaken the door's structure.
In a humid subtropical climate, the cycle speeds up. Spring thunderstorms bring heavy rain and high humidity. Warm, damp air holds moisture that keeps the bottom edge wet even after the rain stops. That constant exposure is what turns a minor issue into a bigger repair.
What You Can Do Right Now
Start by checking the bottom seal. Run your hand along the edge to feel for gaps or tears. If the seal is damaged, replace it with a new one designed for your door size. Also, clear any debris that might hold water against the door, like leaves or dirt buildup.
Look at the ground slope. If water pools near the garage, you can add soil to change the grade so it drains away. Move sprinklers so they do not hit the door, and extend downspouts at least a few feet from the foundation. These simple steps reduce the moisture that causes rot.
When to Call the Pros
If the rot has gone deep, a simple fix may not be enough. You might see soft wood that crumbles, or the door may not close evenly. In that case, the pros can assess the extent of the damage and help you decide whether to repair the bottom section or replace the whole door.
They can also check for hidden water damage in the door frame and the surrounding wall. Water that seeps into the frame can lead to structural issues. A water damage inspection can reveal the full picture, so you know what you are dealing with before spending money on a temporary fix.
- Soft or crumbly wood at the bottom edge
- Door sticks or does not close properly
- Visible mold or mildew on the door
- Damage extends into the door frame
- You are unsure how far the water has spread
Preventing Future Rot
A good finish is your first defense. Repaint or reseal the bottom of the door every couple of years, especially if you live in a humid area. Use a paint or sealant made for exterior surfaces, and let it dry completely before closing the door.
Keep the bottom edge clean and dry. After a storm, wipe off any standing water. Check the seal seasonally and replace it when it shows wear. The weather can be unpredictable, so staying ahead of moisture is key to keeping your garage door solid for years.
Water damage does not wait
Call (469) 698-4610 any time, day or night, and describe what happened.
Call Now (469) 698-4610Frequently asked questions
Can I repair just the bottom of my garage door?
Yes, if the rot is limited to the bottom section. A pro can cut out the damaged wood or metal and splice in a new piece. But if the rot has spread too far, a full replacement may be more practical.
How do I know if the rot is just cosmetic?
Press on the soft area with a screwdriver. If it sinks in easily, the rot is structural. Also check for peeling paint or a spongy feel. Cosmetic issues only affect the surface, but deeper rot means the material has lost strength.
Will my insurance cover garage door rot?
Policies vary, and your insurer decides what is covered. Typically, gradual rot from wear and tear is not covered, but sudden water damage from a burst pipe or storm might be. Check your policy and talk to your agent.