All Things Gypsum<br>More on Area Separation Walls
In a previous column, we discussed the breakaway feature of gypsum board area separation walls-also known as townhouse party walls or firewalls-under fire conditions. To review, an area separation wall in this context is a fire-resistant partition separating townhouses for the purpose of preventing fire from spreading from one unit to the next for a code-specified period, usually two hours. The separation wall must rest on the structure's foundation and either extend through the roof to form a parapet or terminate at its junction with the underside of a fire-resistance rated or properly protected roof. The wall must also be designed so that the structure on one side, once consumed by fire, can fall away while leaving the fire-resistive portion of the area separation wall and the neighboring structure intact.
However, fire resistance is not the only feature that a gypsum board area separation wall is expected to provide. Another feature expected or required of an area separation wall is its sound-attenuating properties, i.e., its ability to dampen unwanted sound from adjoining units.