Common Jamb

When it comes to installing 2-or-3-wide windows, traditional products for mulling typically involve using an H mullion that requires sealant or caulking to create a weatherseal.

These mullions have a weaker bond and deflect easily, while also creating additional, unwanted areas for air and water to infiltrate. Harvey offers a superior, common jamb solution that makes installation of multiple units as easy as one, engineered with a one-piece header, one-piece sill, and a single vertical mullion to receive the sashes on either side.

Since Harvey’s common jamb is a single frame with an uninterrupted nail fin, it is stronger and more weather tight, allowing for faster installation and flashing.

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Common Jamb VS Standard H Mull
Along with stability, the vertical mullion is narrower than traditional mulls, allowing for more glass exposure, so there’s less to get in the way of the view.