As multi-family developers and design teams strive to increase urban density in a way that is affordable, wood framing continues to appear as a popular material choice. For the Stella luxury development in Marina del Rey, California, an innovative light wood-frame design allowed the team to stay within budget, while still meeting code requirements, and providing resort-style amenities in one of the highest seismic areas of the country.
There are two maxims about stucco application over wood-framed structures: first, it will crack, and second, owners will not do much about it. Water intrusion through stucco claddings is so common in Florida, re-skinning buildings here after five or 15 years is commonplace, even though it is not always warranted.
The sound transmission class (STC) and impact insulation class (IIC) are ASTM-derived single number ratings that try to quantify how much sound a stopped by partition being tested. Laboratory testing involves an ideal setting for the floor/ceiling assembly—it is isolated from the walls, and there are no penetrations for HVAC, plumbing lines, sprinklers, can lights, or electrical boxes. In the field (i.e. F-STC and F-IIC), the floor/ceiling assembly often sits on load-bearing walls, is connected to the structure, and contains many ceiling and floor penetrations for the items just mentioned. Consequently, the code allows for a lower rating for field scores over those in the lab.
Demand for better floor/ceiling acoustics in multifamily construction has been spurred by consumer desires, new guidelines from code bodies, and stricter enforcement of existing codes. This article reviews important new guidelines, delving into how construction manufacturers have created new products or enhanced existing ones in the pursuit of achieving higher acoustical performance.
From a single-family home to a 40-story office building, all structures are made up of a complex array of systems competing for limited space. Nowhere is this more pronounced than in floor assemblies where HVAC ducts, recessed light fixtures, and plumbing are interwoven with joists and beams.