Noise Flanking Paths – Causes and Solutions

Flanking” is a misunderstood and under-appreciated problem in noise control construction design. It occurs when noise becomes structure-borne and finds a route around an isolated surface, called a “flanking path.”

Stud walls that are attached to ceiling joists and subfloors create flanking paths around isolated ceilings and floors, transmitting noise.

Flanking paths can also occur in double-stud and staggered-stud wall assemblies.

Typical stud wall flanking paths
Typical stud wall flanking paths

Control Vertical Flanking

Isolation products remove the direct connections between the wall, the ceiling joist, and the subfloor. Flanking paths are interrupted and noise transfer is controlled while structural integrity is maintained.

Products

CWCA and Wallmat can be used together or independently, depending on the application. For example, decoupling the top plate with CWCA may be all that is needed in basement home theaters when flanking paths to and from the upper floors are the only concern.

CWCA | Wallmat (learn more)

Controlling flanking paths to floors above and below
Controlling flanking paths to floors above and below

Control Vertical and Horizontal Flanking

When noise to rooms on the same floor is of equal concern, isolating the drywall will serve double duty, adding noise control between rooms while controlling vertical flanking.

Products

IsoMax clips decouple the wall gypsum board from the studs, which interrupts noise paths to adjacent rooms as well as the floors above and below.

IsoMax (learn more)

Controlling flanking paths in all directions
Controlling flanking paths in all directions