Tag Archives: Permanent truss bracing

Reason You Go With Engineered Prints

Reason You Go With Engineered Prints

Yes, I know some of you gentle readers are offended by my harping on how important it is to build only from site specific fully engineered plans. Well, here is a case study.

Reader AARON in CARBON HILL writes:

“Reason you go with engineering prints. My contractor said it’s how we always do it. Well after they fell he said we need to discuss payment on the work I’ve done I paid for all material up front. I’m not paying c**p he should pay me for the lost and damages.”

As far as engineering goes, it appears columns have an unsupported length of under 131 inches.

Why would this be important?

For a roof only building, such as this, columns are carrying all of the bending loads from winds. Sound engineering practice, says wood column’s least dimension (5-1/2 inches) x 50 divided by Ke (2.1 in this instance) equals maximum unsupported length.

5.5” x 50 / 2.1 = 130.95”

K factor approximates length a column actually buckles at. This effective length can be longer, shorter or exact depending upon rigidity of supports. As a roof only structure has no means to transfer horizontal loads through endwall sheathing, columns act as cantilevers (think diving board). For a building with sufficient endwalls Ke would be 0.85 (makes a huge difference).

Truss carriers appear to be sketchy, however not having site loads, nor size, grade and species of them, it is impossible to verify (and none of them appear to have failed in photos provided).

What is absent? Temporary and permanent truss bracing.

I have expounded on how important temporary truss bracing is previously (https://www.hansenpolebuildings.com/2014/12/temporary-truss-bracing/). I advised Aaron this appeared to be the cause of his now firewood. Also – this one is on his builder, who has some cajones asking to be paid when he caused this mess.

AARON responded, “Yep thanks I just thought if anyone wanted to see what happens when your contractor doesn’t follow the prints. Feel free to share with anyone. We will be ordering a new building kit and go with a contractor with more references. Thanks.”

Currently, there is such a shortage of builders, every Chuck-With-A-Truck, a hammer, circular saw, big dog and loud radio seems to think they can hop in and make big money. Don’t be caught in Aaron’s situation – always thoroughly vet any contractor https://www.hansenpolebuildings.com/2018/04/vetting-building-contractor/.

Permanent Truss Bracing

I have to give a lot of credit to Building Department plan checkers and field inspectors. They have to know a lot of stuff, about a myriad of different areas of construction. Even one who is an expert at what is written in the Building Code itself, would be only fluent in a small portion of what it takes to construct a Code conforming building, as the Building Codes now reference a litany of other publications and documents. Think of it as being similar to the IRS income tax code.

Puts it into perspective, doesn’t it?

truss bracingPrefabricated roof truss drawings (provided by the roof truss manufacturers) give the recommendation for how the truss designer feels the trusses should be braced, however the ultimate design of the truss bracing system, is the responsibility of the building designer (registered design professional – engineer or architect).

Recently one of our clients advised our office of the request, from their building inspector, for an email or letter from the engineer of record on their new Hansen post frame building. The request was in regards to the truss bracing system designed by the engineer superseding the bracing shown on the roof truss drawings.

Although the following may sound like it is in a foreign language, on the first page of the engineered building plans is a series of “General Notes”. Note 9 says:


ANSI/TPI 1-2007 pretty much lays out who does what and how. Here are some relevant excerpts: Responsibility Exemptions.
The Registered Design Professional for the Building is responsible for items listed in 2.3.2, and is not responsible for the requirements of other parties specified outside of Section 2.3.2. Method of Restraint.
The method of Permanent Individual Truss Member Restraint/Bracing and the method of anchoring or restraining to prevent lateral movement of all Truss members acting together as a system shall be accomplished by: Method Specified by any Registered Design Professional.

The method of Permanent Individual Truss Member Restraint and Diagonal Bracing for the Truss Top Chord, Bottom Chord, and Web members shall be permitted to be specified by any Registered Design Professional.

On this particular project, general note 9 covered the permanent lateral truss bracing system and is sealed by the Engineer of Record. This makes the request for an Email or letter from the engineer to cover the same topic redundant, as well as an unneeded expense to the building owners (engineers do not just do work for free).

Potentially, the building inspector could decide to alter the truss bracing system designed by the Engineer of Record, however this opens up an entirely new can of worms. In making an alteration, the inspector could be in violation of the laws which govern engineers, as well as placing the jurisdiction in a liability situation should a failure occur.