Should You Switch Over to the QuickTie Cable System?
By: Jorge Ibacache - Technical Services Engineer & Kevin Barnes - Architect/FC
July 31, 2017
The QuickTie cable connection system provides a reasonable means for resisting wind uplift on buildings where wind uplift pressures exceed the resisting abilities of a nailed plywood exterior sheathing. This is especially relevant, since all buildings across the nation are now required to be engineered according to the ASCE7 standards - causing uplift concerns to heighten in areas where this was not previously considered. In fact, before these standards were considered, many homes were built using just nails and a few metal brackets. When properly designed and coordinated with other trades, utilizing tie-rods when building homes provides a sturdier structure capable of withstanding greater catastrophic loads such as tornados, hurricanes and earthquakes. The purpose of this article is to inform you of what the QuickTie cable connection system is and how it is installed, as well as pinpoint the pros and cons of the product in comparison to traditional competing systems. Do note that this article will not be considering the cost of the Quicktie cable system or any other cost variations resulting from structural design changes.
What is the QuickTie Cable System and How is it Installed?
The QuickTie cable connection system replaces traditional threaded rod systems, and when installed correctly can have a series of benefits. It is important to note, however, that just like switching over to any new product, the trades involved will have to learn a new system - thus heightening risk during initial installation.
The cable system comes with a label on each cable which has been engineered for the uplift reactions, indicating the number of turns needed for proper tensioning. Installers will need to be able to read and understand the labeling. Once tensioned, pulling and releasing the cables should produce similar sounds, allowing inspection time to be much more efficient. On the other hand, we have often identified nuts on threaded rods or anchor bolts that were installed “finger tight” and can only be determined by feel and not by sight.
QuickTie Cable System Benefits
The QuickTie cable connection system is especially beneficial when it comes to addressing wood shrinkage. Since the cables are not as static as threaded rod systems, they are able to better adjust to the change. Also, in certain circumstances, the cable system is able to replace threaded rods 1 to 1 in terms of simplicity of installation.
For example, with structural designs that include continuous threaded rods from a concrete spread footing or monolithically poured slab on grade, the cables would be able to take the place of the threaded rods, as the threaded rod locations would have already been taken into account as a part of the original structural design.
Additionally, the QuickTie cable system has undergone a considerable amount of testing by licensed engineers, and has addressed code conditions on a local basis to ensure the best outcomes.
Instances Where QuickTie Cables are Not Interchangeable
If the QuickTie cable system is being considered for the replacement of the traditional vertical reinforcing rod and grout in concrete masonry walls, wall stiffness in the short direction will need to be considered. We also have a concern for the elimination of the vertical reinforcement with hooked ties into vertical grouted down cells, especially at large masonry openings such as garage doors. The grouted horizontal elements in a concrete masonry wall also helps reduce cracking and/or crack size as a result of shrinkage of the block as it dries.
Although a home built with either system will resist the lateral load just the same, they are not interchangeable. Homes designed with a continuous shear resisting system, like base plate connectors would not be able to be retrofitted with tension cables or tie-rods without redesigning almost every structural component.
- Top plates would need to be reinforced at the anchored locations and between the rod to withstand the additional compression and flexural stress loads.
- The location and type of wood studs would need to be adjusted to accommodate the imposed compression loads.
- Continuous perimeter footings may need to be reshaped to accommodate the additional concrete mass if required.
- Horizontal runs of plumbing and electrical lines may need to be relocated to accommodate the tension ties.
Quality Built has a particular concern with the anchoring method involving concrete. If a threaded rod and double nutted backup plate is installed prior to the pour, this would eliminate the concerns of a drilled and epoxy cemented connection. Our concern with the epoxy method is the need to monitor the drilling and cleaning of the drilled holes prior to inserting the epoxy material. This method requires gauging the depth of the drilled hole, an air nozzle with a tube capable of reaching the bottom of the drilled holes to blow out all of the dust, and inserting the epoxy ensuring that the epoxy reaches the bottom of the holes. Best practice would include field pull tests on all drilled and epoxied threaded rods.
The QuickTie cable system does have its benefits, and the need for resisting wind uplift in buildings is becoming more and more prominent across the nation due to the implementation of the ASCE7 standards. The QuickTie cable system is able to maintain tension even when wood shrinks and can also replace threaded rods 1 to 1 in certain circumstances. It is important to consider, however, that the cable system does not seamlessly replace threaded rods in all circumstances. This would require changes in structural design and the use of specific materials. In order to best determine the circumstances in which the cable system would be of best use, Quality Built recommends that you consult with our licensed architects and engineers to perform a Technical Peer Plan Review and to evaluate value engineered submittals to identify possible conflicts and gaps in details.
About the Authors
Jorge Ibacache is a licensed civil engineer and has been a certified building inspector for over 15 years. He has performed thousands of structural inspections while providing plan reviews, code enforcement and building department services for multiple jurisdictions. Jorge has an in-depth knowledge of building codes, design standards and local ordinances.
You can reach Jorge at [email protected]
Kevin Barnes has been a Florida registered architect since 1997. He has performed thousands of inspections, including forensic investigations, remediation, risk assessments and quality control inspections for both commercial and residential projects. Kevin is an expert witness for construction components, specializing in exterior and interior investigations for litigation regarding proper installation of sealant and waterproofing components.
You can reach Kevin at: [email protected]
- QuickTie Catalog
- Floridabuilding.org: QuickTie Systems & QuickTie System Post-Tensioned Concrete Masonry Wall Applications