Is Cutting Off the Nailing Fin on New Construction Windows Acceptable?

24 April 2025 3 answers
Asked by SunnyDaze92
I'm having some concerns with my contractor, who is cutting the nailing fin during the installation of new construction windows. Everything I've come across suggests that this could potentially void the manufacturer's warranty, but the contractor just shrugged it off, saying "that's how they do these." Can anyone clarify whether this is an acceptable installation method for new construction windows?

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WindowWizard99
If you're installing new construction windows without siding yet, cutting off the nailing fins is a big no. You should definitely ask the contractor to replace those windows. New construction windows should be mounted with the nailing flange, not by drilling through the frame. But if you're putting new windows in where there's already siding, then cutting the fin might be acceptable. Just be cautious, especially regarding warranties!
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FixerUpperGal
What your contractor is doing sounds off. New construction windows shouldn’t be installed like replacement windows! Check with the window manufacturer to see if they approve of the nailing fins being removed. If they say it's not okay, you might need to have the contractor adjust your warranty. It’s a good idea to consider getting a third-party inspection just to be safe.
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DIYEnthusiast88
Cutting off the nailing fins is definitely not standard practice! Nailing fins are specifically for new construction, while replacement windows are designed to fit into existing openings. Make sure that you don't let them proceed with this installation without addressing these concerns.
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