Stucco cracking around vinyl windows is a common concern, especially for homeowners in climates with extreme temperature changes. Isabel reached out with a question about whether these cracks are normal and if caulking is the right solution.
Question from Isabel:
In the past year, I had full vinyl window replacements with a full nail fin flange install and synthetic stucco bullnose application. Several of the windows have developed some separation/"cracks" between the stucco and the window frame.
The windows were flashed-in and weather sealed. The installers have stated that this is normal and that the windows will not leak. They offered to caulk, but I’m not sure if that is warranted.
Would caulking actually just retain the moisture and not allow the water to drain away? High desert climate with weather extremes. Thank you.
Answer:
Hi Isabel, What you’re experiencing is completely normal, especially with vinyl windows. The separation or cracking between the stucco and window frame often happens because the two materials (vinyl and stucco) expand and contract at different rates due to temperature changes. This is common with dissimilar materials, particularly in climates with weather extremes, like a high desert.
Shrinkage in the stucco can also contribute to this. Stucco naturally contracts slightly as it cures, which can lead to minor cracks or gaps around the edges of windows.
Caulking these cracks is a good idea, though not absolutely necessary. While the cracks themselves won’t typically cause leaks if the windows were properly flashed and weather-sealed, caulking can help minimize water intrusion beyond what’s normal. It won’t trap water or prevent drainage as long as the window system was installed correctly.
In short, caulking provides extra protection and peace of mind, but the separation you’re seeing isn’t unusual or a sign of a major issue. It’s worth noting that this separation is likely to occur all the way around the window over time. If you decide to caulk the cracks sooner, you may need to reapply caulking in new areas that separate later on.
Hope this clears up your concerns! 😊
