Cities across the U.S. are booming with new multifamily projects pushing the status-quo of wood frame construction. Many developers are experiencing new challenges presented by the frenzy of urbanization and the general increase in wood frame construction.
With the recent rise in urban projects, the complexities of structures are increasing demand on industry standards. The following trends are becoming more common on projects that CLP Systems designed and installed during 2015 and are projected to work on during 2016. These trends are derived from projects that, like many purpose-built student housing projects, are three- to six-story wood frame structures.
- Elevated Post Tension Slabs – Developers and engineers are challenged with maximizing construction on urban space available and designing vertically is the trending solution to meet increased demands of parking, retail and apartment units. Elevated slabs allow for parking and retail spaces available under the wood-frame construction. These slabs are typically designed with tension cables running the span of the slab, which can cause difficulties with the anchor tie-down installations. This demand has increased the level of focus, time, and money spent in anchoring tie-downs on an elevated slab.
- Rod Systems Specified – In 2015, 49 percent of the projects we worked on were specified with a rod system for the anchor tie-down scope. These structures are typically between three to six stories above grade. The increase of engineers nationwide who are preferring to design with rod systems is due the ability rod systems have to compensate for wood shrinkage, provide easier and safer installations and design for wind uplift, shear wall overturning, and settlement in one system. We expect to see a dramatic increase of rod systems specified in 2016.
- Rising Anchor Issues – Slab loads are quickly increasing with the rise in floor levels on projects. With developers looking to get more out of available property, many engineers are challenged with slab design requirements and anchoring solutions. We continue to see new challenges and solutions on the slab levels, but there has recently been a lot of attention on epoxy anchoring and new cast-in-place solutions. Epoxy anchoring has become increasingly popular with general contractors and framers because of its ease of installation. However, there are uncertainties about the long-term capabilities of epoxy as the load demand on anchoring increases. This trend will be challenged in 2016 as new standards are created.
- Shortage of Sub-contractors – After 2008, many sub-contractors decided to close their businesses due to the slowdown in construction activity. Businesses who survived the recession are again growing with the recent boom of the multifamily sector. However, the industry is growing at a rate beyond the capacity and number of skilled sub-contractors available. Many have started to turn projects down due to their lack of capacity to service the project. This will continue to be a threatening issue for developers and general contractors pushing to meet deadlines while ensuring the best construction standards.
- Wood Shrinkage Compensation – Conventional hardware does not address settlement issues that occur in wood frame structures and has historically been known to loosen and buckle on structures with multiple floors. This buckling can cause interior finish issues and water filtration on the exterior. To compensate for wood shrinkage engineers are designing rod systems with take-up devices. This trend is expected to become the new standard in 2016 ensuring long term structural integrity on wood frame buildings.
These recent construction trends are here to stay, but new solutions are always being developed to meet the demands of engineering.
Brent Bumgarner is head of business development for Birmingham, Alabama-based CLP Systems.