Engineer needed for decorating trusses? 3

[rjpope42]

Hi all, engineer from another realm stopping in. I have a BSEE and Masters of Engineering in Materials Science, but neither of those qualify me to do structural engineering so I'm seeking some quick advice.


I'm looking to decorate the exposed 40' trusses in my shop, the thought being:
-attach dimensional lumber to the sides of the trusses to just make them appear to be the same thickness as the 6x6 poles.
-cut the slop off the 2x4 lateral braces, and maybe thicken them for visual balance
-add extra knee braces for symmetry
-stain all the wood dark brown

I've read that decorating trusses "usually doesn't require engineer involvement", and I'm removing nothing, only adding. But better safe than sorry, so I'm here to see if this gets a reaction of "nah you're just adding decoration that, if anything, is extra bracing so nailgun away" or if it's more like "hire a structural engineer or your trusses will collapse under their own weight"

Thanks for helping me get sorted!

(Working on uploading pics)

 

[JStephen]

A house we lived in several years ago had a couple of exposed beams in the ceiling, and they either were, or were covered with, what was basically black Styrofoam. Looked okay, they were dark enough, you couldn't see a lot of detail anyway. But if that's a feasible approach, it would take care of the weight issue and add some sound dampening, for better or worse.

 

[phamENG]

KootK - thanks for sharing that experience and knowledge. I suppose I chose my words carelessly. When I said they didn't make much sense theoretically, I meant they're difficult to justify using typical wood connection principles. I had the chance to try a couple years ago - couldn't do it. The list values and the numbers we were calculating were way off. I understand that all wood connections and connectors have been validating by testing - the truss plates just feel a bit more like voodoo than anything else I've dealt with in wood. Though it is, as you said, an elegant solution to the problem of light frame wood truss connections.

Most of the prefab truss buildings I've had to analyze for retrofit have required some sort of modification to get them to pass. I haven't done one exactly like this, so you're probably right that there's nothing to really worry about. I'd just approach it with plenty of caution.

 

[KootK]

To an extent, the retrofit issues are probably more about the nature of trusses rather than pre-fab trusses per se. With common, trabeate framimg, members usually have a handful of things to consider and are only governed by one concern with the others passing comfortably.

Because a truss is an assemblage of members and connections, there are a ton of things to check and a large set of them that may be designed marginally. I would submit that is also true of steel trusses, heavy timber trusses, and site built trusses as well. It's just sort of the cost of doing business when using such a highly efficient framing member typology. No free lunch.

Assessing the plated connections is a challenge when approached from outside the industry for sure. How did you approach it? TPI code provisions and manufacturer plate data?

 

[phamENG]

Valid point. Most of the heavy timber trusses I've worked with are well over 100 years old, so they were never "analyzed" in the first place. It's pretty hit or miss there in terms of modern building code compliance if such compliance is required by the work - some pass with excess capacity, some don't. The assemblies I've looked at from the 30s on get a bit tighter and more efficient.

No, we wanted to see how the data would compare to an equivalent nail pattern. Admittedly our procedure was a roughly approximate guess to begin with, but we were trying to draw some line of similarity as a baseline for understanding the TPI provisions and test data. Didn't really work.