10/08/2026
Thinking about replacement windows?
Before you buy a single thing, there is one crucial technical detail you need to understand that most window salespeople will completely skip over: Fl**ge vs. No Fl**ge.
Understanding how a window must be installed is the foundation of a successful project. Let’s break down the truth behind window replacement so you can avoid a costly, leaking mistake.
1. The Golden Rule of Fl**ges
There are two main ways to install new windows into an opening: using windows with an exterior perimeter fl**ge (nailing fin), or using windows without one.
To decide what your house needs, you have to evaluate your exterior wall:
• Siding & No Old Frame: If your exterior walls are covered in siding and there is no old wood window frame staying in the wall, you must use a window with a fl**ge to get a proper seal and avoid water pe*******on.
• Check the Old Window: If the windows being removed have a fl**ge, the new ones must have a fl**ge. If the old ones do not have a fl**ge, the new ones may possibly still need a fl**ge depending on the wall structure.
2. The Biggest Mistake Homeowners Make ⚠️
The biggest mistake you can make is assuming the person selling you the windows knows how they need to be installed. Most window salespeople have very little hands-on installation experience.
The person who should make the determination about fl**ges is someone with actual field expertise in window installations—and most of the time, that is not the salesperson.
3. When Can You Go Fl**geless?
The only time a new window can for sure be installed without a fl**ge is during a pocket/insert installation. This is when the new window sits entirely inside an old wood window frame that stays on the wall, leaving the original connection between the old frame and the wall undisturbed.
Crucial Warning: If you choose this method, you must absolutely ensure the old wood window frames staying in the wall are completely free of rot.
4. Shifting to Window Selection 🪟
Once your installation method is locked down, you can finally focus on the actual windows. Start with these two decisions:
• The Style: Many people stick with their original window style, but don't be afraid to explore alternatives that might offer better ventilation or views.
• The Material: You have choices ranging from classic wood and various qualities of PVC (vinyl), to fiberglass and composites (mixtures of PVC and wood fiber/sawdust).
Note on Quality: There are many different grades and quality levels across these materials. Generally, quality reflects cost—but not always. Many homeowners end up paying top dollar for mediocre windows. Do your research on the specific window grades!
5. Choosing Your Team 🤝
At the end of the day, a window is only as good as the hands that install it. You have a few directions you can go:
• A national brand paired with an independent contractor.
• A local factory manufacturer that handles everything from engineering to installation.
• Franchisees or national sales and installation companies.
Forget the brand names for a second—the best way to handle this choice is to look for a manufacturer and an installation team that you can independently verify and trust to do the job right.
💡 Want to see these installation differences in person?
Come visit us at the Royal Windows and Doors Bay Shore Showroom & Factory to look at our display models, or check out our Commack Showroom on Jericho Turnpike!
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