Mullion Trim Cap

The Mull-It-Over Mullion Trim Cap is a simple, clean, metal trim that covers the connection between a partition wall and window mullion. Without Mull-It-Over, this connection is an acoustically weak path that allows for sound transfer between adjacent rooms. The Mull-It-Over Mullion Trim Cap is designed to maintain the acoustical performance of the wall without acoustical degradation from the mullion. The trim cap is easy to install during new construction or added during retrofit. Tested for STC 55/60 with 1-hour and 2-hour fire ratings. Available in a variety of standard and custom profiles and finishes to match the curtain wall.

What is a mullion trim cap?

A mullion trim cap is a sound isolation element that is placed on top of a mullion to improve its acoustical integrity.. By covering the mullion, it helps to create a more airtight seal, reducing the transmission of sound between different spaces and improving sound insulation properties. This makes it beneficial for environments where noise reduction is a priority, such as in residential, commercial, or office settings.

Are mullion trim caps necessary?

Mullions do not provide adequate sound isolation between two residences, offices, conference rooms, etc. In order to meet industry standards (and regulatory requirements in some states) for sound isolation between residences, the mullion must be acoustically treated in some fashion. In order to meet industry standards for speech privacy between two offices or conference rooms, the mullion must be treated in some fashion. While it is possible to install a field-built mullion trim cap to address this issue, the end product is aesthetically inferior to the Mull-it-over trim cap and also would not have any associated acoustical or fire testing.

Does Mull-it-Over mullion trim cap have fire testing?

Yes Mull-it-over acoustical mullion trim cap is available with one and two-hour fire ratings.

Does Mull-it-Over mullion trim cap have sound testing?

Mull-it-Over is available in STC 55 and STC 60. This mullion trim cap system provides a high level of sound isolation.

What are the advantages of mullion trim caps?

Mullion trim caps offer several advantages in windows and doors. From a sound isolation perspective, they can help improve the overall soundproofing capabilities by creating a tighter seal and reducing air leakage. Additionally, mullion trim caps provide an aesthetic enhancement, adding a decorative touch to the mullions and giving a more polished appearance to the windows or doors.

Are mullion trim caps easy to install?

Yes, installation is simple with standard tools. The mullion trim cap can be cut using a non-ferrous carbide saw blade, jigsaw or other non-abrasive metal cutting blade. The mullion trim caps are typically installed after the walls are painted but before window treatments are installed.

How does the Mull-it-Over acoustical mullion trim cap allow for the differential movement between the curtain wall and the building partition?

The Mull-It-Over Mullion Trim Cap attaches to the wall, but does not contact the curtain wall mullion. The assembly includes a compressible closed cell foam gasket between the end of the mullion cap return leg and the interior face of the glass. When properly installed, the mullion trim cap allows for differential movement in all directions.

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Product Name: Mull-it-Over

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