A Real Bracing Demo - Will it Show What Framers Already Know?
How much temporary bracing will the following 50’ truss need?
According to the BCSI booklet, the answer looks like the “up to 60’ truss” in the following illustration:
At the BCMC show in Omaha, SBCA will be setting up two roof truss systems comprised of five identical 50-foot trusses. One truss system will be fully braced according to the guidance provided in the BCSI booklet. The other truss system will have bracing within the web-member plane only. Attendees will have an opportunity to walk on the system and get a feel for the truss stability of each bracing approach.
Installing lateral restraint and temporary diagonal bracing during the construction process is a challenge every framer faces. Scott Stevens, President of Modu Tech and Director of the National Framers Council (NFC), made this point in a May 31 letter to the SBCA Executive Committee:
“To set the foundation for future [NFC and SBCA] discussion, I spoke with two of my key teammates at Modu Tech, Carl Cherney and Scott “Scooter” Soldan, and the first thing that they said to me was that there is too much bracing required. Why was that the immediate comment from them when I brought this up?
- Bracing is very hard to estimate when costing and pricing the construction projects that we undertake. Consequently, we may over-estimate the material required thereby increasing our bids to cover ourselves.
- The guidance provided by BCSI is helpful but the application is not framer friendly. Inspectors and general contractors are looking at the framer to explain, justify and or comply with the bracing requirements. These conversations can prove to be challenging. The outcomes can be painful for the framer…….
Areas of concern to framers include:
- First and foremost safety.
- Bracing the top chord of any truss is inherently dangerous.
- Attaching bracing and taking it off and then having to apply sheathing to the top chord creates risk each time work has to be done on the top chord,
- Fall protection is challenging if not impossible to do,
- This adds a great deal of labor time if BCSI is followed as written and shown….
- The cost to install bracing if it is implemented per BCSI.
- The cost of bracing material.
The safety, labor and material issues cause many framers to do bracing easier than BCSI as it is prescribed……
The proposed approach by SBCA as defined in the presentations I reviewed where SBCA states as its goal:
“The goal of the work to be performed is to provide the technical and analytical justification needed to support a more material and labor efficient/effective approach to restraint and bracing that is in the current BCSI. Done well this will lead to better truss installation safety and can be achieved through: 1) Engineering analysis, if possible, 2) Truss system testing, if needed, and 3) Engineering analysis calibrated to testing.”
This is the help that framers need. The ideal bracing approach for framers is to apply temporary bracing, which can also be used as permanent bracing. In this way, the installation of bracing can be done more safely by not having to touch bracing more than once during any installation process. This type of approach would greatly reduce a framer’s time working on top of trusses and associated fall hazard risks.
As SBCA also stated in information provided;
“..if framers believe that the amount of bracing being requested to install makes common sense and the installation process is easy to understand and safe, framers will be more likely to view bracing positively and actually do it. Neither BCSI nor TPI 3 seem to have achieved an approach that does not bring us back to the point of view that “there is too much bracing and it takes too long to install.”
It is my understanding that the Executive Committee has recommended that the group look at conventional framing and component framing from both a bracing and fall protection perspective as SBCA works through the issues presented here. This is a great idea as I am not aware of a comparison like this ever being done. This can shed light on a wide variety of issues.
Modu Tech would be pleased to provide the space to set up a truss versus conventional frame demonstration project, to allow anyone who is interested to learn first-hand about the reality of framing, bracing and fall protection. Please let me know if this remains an interest of SBCA and we will work with SBCA staff to implement this.
Since 1984, the structural component industry has provided bracing guidance to installers. In an effort to increase the efficiency of the installation guidance found in these documents, as Mr. Stevens mentions above SBCA has begun looking at opportunities to move temporary bracing off the top chords of trusses and into the web-member plane, so that restraint and bracing application approaches that are more framer-friendly in the field.”
SBCA has taken Mr. Steven’s advice and will have a set of 5, 50 foot trusses fully braced and a set of 5, 50 foot trusses web-member-plane-only braced. Through this approach, all BCMC attendees will be able to see what BCSI bracing really means visually and also walk through the two different applications of bracing to see the differences.
Please make your way to the BCMC showfloor and stop by for a tour and conversation regarding BCSI and the future of bracing.