There are a few places in the home where caulking shouldn't be used. These places include any wood to metal joints, weep holes on windows, and garage door panels that create gaps. According to Elegant Painting, the gaps created when trim boards sit atop the siding shouldn't be caulked either since it will affect air flow and drainage.   It's important to allow air circulation in these areas to prevent moisture build-up and mold growth. Moreover, weep holes need to be kept clear so that water can escape from the home. Failure to do so can result in serious water damage.   It is recommended to leave the garage door panels unsealed so that they can expand and contract as needed. By avoiding these areas, you can ensure that your home is properly sealed and protected from the elements.