TECTUM Roof Panels or similar product - lateral support for structural steel

[PT999]

I am looking at a Circa 1960's building with TECTUM or something similar roof panels, and wondering if this provides lateral support to perimeter roof beams. I don't think so, as the bulb tees supporting the panels look real small (from the little that is visible), but would like to hear from others. Span of the panels is 10 ft.

 

[thaidavid40]

The bulb tees, maybe. The Tectum panels diaphragm strength, probably not. These panels get so soft and weak with the least little exposure to roof leaks. Don't trust it any further than you can throw it to the nearest dumpster.
Dave

Thaidavid

 

[Ron]

PT999...are you sure? The length of the panels is probably 10 feet, but the span is likely 24 or 36 inches.

The bulb tees do provide lateral bracing, the Tectum (or similar) panels do not.

 

[KootK]

For the bulb tees to brace a beam, would not the tees themselves need to be axially restrained by the Tectum panels (diaphragm capacity)? Seems to me it's an all or nothing deal.

Some modern versions of the system have diaphragm capacity clearly: Link

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[PT999]

Regarding Tectum span, the next visible steel beam supporting the Tees is 10 ft away. The panels themselves have gaps between each other in the 10 ft direction, they appear to be 2 ft x 4 ft (or so - I need to check dimensions again, but not 10 ft long).
and finally CMU walls and roof near the perimeter leak (but not thru the roof membrane, its perfect).

And maybe its not actually Tectum, but it looks likes it.

The whole purpose of this project is to deal with the leaks.

The problem is if the existing steel beam is not laterally supported, it is undersized, (if laterally supported then OK) and getting the larger steel section in its place may not work because flanges get a little wider.

 

[hokie66]

I agree with Ron. The bulb tees brace the supporting beams, and the Tectum provides the small amount of bracing required for the bulb tees, but I wouldn't depend on any diaphragm capacity.

 

[XR250]

How do all of these old buildings not fall over without explicit roof diaphragms? Inquiring minds want to know!

 

[Ron]

XR250.....Stress distribution, stiffness and never seeing the design conditions.

 

[XR250]

I'll second that and add unitintended composite action to the mix

 

[hokie66]

Trickle theory.

 

[msquared48]

Anti-gravity and anti-wind generators so that no lateral forces are ever seen.

Mike McCann, PE, SE (WA)

 

[msquared48]

Oh, and strange as it may seem, older structures, depending on the structural framing system, do develop a structural memory that is very hard if not impossible to quantify.

Kinda the flip side of older engineers losing their memory.

Mike McCann, PE, SE (WA)