What Is A Triple Leaf Effect?

To a view graphics along with this article, we recommend reading it on our site here at isostore.com/concept/triple-leaf-effect-retrofit-installation.

A triple leaf partition has two air cavities rather than the typical one air cavity. Similarly, a quadruple leaf partition has three air cavities. Triple and quadruple leafs are most often created when constructing a new wall in front of an existing wall. The other common ways include installing resilient sound clips or resilient channel over existing drywall. This applies to both walls and ceilings alike. A leaf in a partition is a solid layer, like drywall or plywood.

It is not illogical to presume that a quadruple leaf wall would have the best sound isolation. After all, the sound has to go through drywall, air space, drywall, air space, drywall, air space, and then again drywall, often with insulation within each air space. In a double leaf wall, the sound has to make it through only one air space. While it makes sense that the quadruple or triple leaf assemblies are better than double leaf assemblies, it is, unfortunately, not the case.

Testing For Common Walls With Multiple Leafs

The STC values shown below for the common framing assemblies are from a series of tests commissioned by Owens Corning and Pliteq. While STC does not tell the entire story, it is clear that the triple leaf and quadruple leaf assemblies should be avoided whenever possible.

Double leaf with resilient clips – STC 61

Triple leaf with resilient clips – STC 48

Double leaf with standard framing – STC 63

Triple leaf with standard framing – STC 53

Quadruple leaf with standard framing – STC 44

Testing For Clipped Assemblies With Multiple Leafs

The STC values shown below for the GenieClip assemblies are the results of independent tests. The performance loss created by the retrofit clip installation was significant, but lessened by insulating the space between the existing drywall and new drywall with an R-8 insulation. The retrofit performance would have been much lower without the extra insulation.

GenieClips installed to wall studs over existing drywall – STC 48

GenieClips installed directly to wall studs – STC 61

GenieClips installed to ceiling joists over existing drywall – STC 48

GenieClips installed directly to ceiling joists – STC 54

Comments are closed.