"Pre-Engineered Metal Building Issue 5

[Ron]

Does anyone know of a source for older versions of the Metal Building Manufacturer's Association (MBMA) Manual? The 2006 version is readily available, but older versions seem to have disappeared. I checked with MBMA and they don't provide.

Specifically, I'm looking for translucent roof panel criteria for any building constructed prior to 1985.

PS...For the record...I hate the term "pre-engineered metal building".....EVERY steel frame commercial building is "pre-engineered!!"

 

[msquared48]

I have the 1986 version of the Low Rise Building Systems Manual by MBMA.

Do you have a section number to start with? There is nothing listed in the index for translucent roof panels.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[msquared48]

In the Nomenclature section, they refer to them as "Translucent Light Panels." Looking...

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[msquared48]

They are also referred to as "Plastic Panels in the index, but I do not see anywhere in the book those terms mentioned outside of the Nomenclature section.

I'll see if I have anything else.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[JAE]

Ron, I think I might have some old MBMA manual/code book of some sort. I'll look for it tomorrow.

Also - think of it this way..."they" use rinky tink [red]metal[/red] that blows down in the windstorms. "we" use [red]STEEL[/red].

 

[msquared48]

I also have the 1996 and 2002 editions, but that's it. Sorry.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[Ron]

Mike and JAE...anything you can provide will be helpful. In particular I'm looking for any specific load requirements on translucent roof panels (skylights) for metal buildings. The 2006 MBMA manual and specifications allude to a load requirement (concentrated and distributed load) but they seem a bit out of whack for skylights.

I am evaluating the skylights on a building that was built in the 1970's and the obviously brittle skylights are original. They are not the same type of layup as current skylights (they have a random roving in the glass fiber reinforcement; whereas, the current ones I've seen have directional woven or non-woven roving)..

Ron

 

[msquared48]

In the 1996 "Low Rise Building Systems Manual" by MBMA, Section A-15, Serviceability, on page VIII-15-3, there is a list of six items that they intend to discuss, skylights being the second.

Interestingly enough, that does not happen and they skip directly from 1 to 3 (Roofing to Cladding), never discussing skylights. Bummer.

If an errata sheet was made for this omission, intentional or otherwise, I never got a copy.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[msquared48]

This is really convoluted, but in the 2002 MBMA "Metal Building Systems Design Manual", the same omission mentioned above is there.

On top of that, under Part IV, Common Industry Practices, Section 6.2.2, Work Usually Not Included In Erection, item #6 lists "Glazing for the Metal Building Accessories", which would definitely include any "skylights". The material is not specified, only the word "glazing". This would seemingly exclude translucent panels, although they are technically skylights.

In Part V, Guide Specification", Section 3.5 - Translucent Panels, Section A says that "The the translucent panels to be installed in accordance with manufacturer's instructions and details."

It seems to me, reading between the lines here, that the MBMA does not have any specs for these "skylights" or "transluucent Panels" or wants to due to the obvious omission and no erratas. It seems to be left up to the building manufacturer to set those specs, if any. Particlularly when the "glazing" appears to be manufactured by others than the metal building manufacturer in either case.

Interestingly enough, the glossary does recognize a skylight as different from a translucent panel.

So, are you sufficiently confused now? Hopefully JAE has more success.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[msquared48]

Belaboring the point, for lack of anything else, as either is a form of "cladding", and technically part of the roof structure supporting vertical loads, the provisions of the 1982 UBC would still apply here for snow and wind (uplift and downdraft) loading as a guide for the MBMA. Load combinations of that era would apply.

Logically, it would seem that the panels should have been designed to resist these loads. However, have you ever seen panels other than one size or thickness of material?

Pandora's box it seems.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[ishvaaag]

The trademark RELON (here listed in A and B variants) was the most commonly used in Spain in the eighties and around.

http://www.fbtecnopolimeri.com/index2.asp?P=prodotto1

At this site you have how their current (mechanical et al) properties are listed.

 

[ishvaaag]

This was sinusoidal deck traslucent pastic, and I vaguely remember it be randomly reinforced by then.

 

[hokie66]

Just my $0.02 worth. I doubt the MBMA folks would have wanted to say too much about translucent sheeting. The manufacturers of the sheeting would have had tables, which are probably "lost" by now. At any rate, if the stuff has been there since 1985, don't step on it!

 

[JRGse]

"...I am evaluating the skylights on a building that was built in the 1970's...".
The 1974 MBMA Manual did not may a specifications for translucent panels. Attached is a copy of Section 12 of the '74 manual.

 

[Ron]

Mike...thanks again...that's actually helpful to know...they're "silent" on translucent panels

hokie66...interesting statement you made.. "At any rate, if the stuff has been there since 1985, don't step on it!"

I agree completely, but someone did and he's not around to tell about it. Trial is next week...will discuss when it's over.

 

[Ron]

Interesting development...just got a call from the attorney. The case settled. Here are the facts:

Owner purchased existing pre-engineered metal building about 20 years ago. The building was over 10 years old when purchase by current owner, so building was constructed in mid-1970's.

After multiple hurricanes in 2004 in Central Florida, owner experienced roof leaks in metal roof panels. Insurance company investigated and would pay for replacement of all fasteners in the roof panels (gasketed TEKS screws).

Owner hired handyman company who had done some other work for him, to replace fasteners. Handyman company owner had tenant in one of his properties who was behind on rent and needed work to do. Handyman company owner hires tenant to install fasteners. Tenant had no construction training and no roof experience.

Went up on roof on a Sunday morning with drill and bag of screws. Handyman owner said he warned the guy to look out for skylights (flush mounted translucent panels) and not to step on them. Handyman owner left premises, leaving his employee unsupervised. He added a few screws (incorrect procedure...should have removed and replaced oversize head screws) and sometime that morning, step onto one of the 30+ year old skylights and fell through, landing on a car and the floor. He died from the fall.

His survivors sued the Handyman company, the Handyman company owner, and the building owner. The building owner was the only one with insurance since the handyman company owner carried no worker's comp or general liability insurance.

The survivor's "expert" and lawyers claimed the owner was responsible because he should have put guards up around the skylights or put a structural grid under the skylights to make sure no one would fall through. The owner never went on the roof, had no maintainable equipment on the roof, and didn't know anything about how the roof was built or what the OSHA requirements would be for employees working on a roof....the reason?...he was not the employer, did not have employees on the roof, and had no reason to know roofer's OSHA requirements. We countered that a skylight of that age would not and could not support a person and as long as it didn't leak, the owner would have no reason to maintain or even consider the skylights...they were performing their function.

Their expert tested new skylight material but failed to note that it was manufactured quite differently than the original skylight. Newer skylights are required to meet higher standards than the old ones. The old ones only had to meet minimal roof live load requirements (20psf) and had no concentrated load criteria.

Anyway...they settled the case because the insurance company didn't want to take a death case to trial. The settlement was apparently about what the trial would have cost to fight it, so the insurance company came out ahead, since a jury could have and likely would have awarded based to some degree on emotion.

The worker's negligence cost him his life. He was not qualified to do the work and was not supervised by his employer. How that became the owner's problem (other than perhaps making a bad decision to hire a Handyman company rather than a qualified contractor) is beyond me, but that's the way litigation works!!

 

[JAE]

Ron, check your email - I sent you portions of the 1974 manual and I also have the 1981.

 

[cntw1953]

Ron:

Excellent closing story.
OSHA mandates the use of guard system and/or personal fall protection equipment that could save lifes, but was ignored quite often with tragic endings.

 

[JAE]

Makes you wonder how many more translucent panels (brittle) are out there.

 

[cntw1953]

Roof panels and support members corrodes and deteriorates with ages, never trust the roof one steps on without fall protection of some kind. I think the translucent panel is quite popular in manufacturing facilities for better lighting.