Engineered Lumber for Commercial Buildings?

[Dan]

Folks --

I ran into this past summer. We ( me and 3 friends from college ) had purchased some pieces of engineered lumber for use in a detached workshop. I had cruised some shelves at the spot and was asking about using some engineered lumber elsewhere - namely for a commercial building ( A paint shop for boaters - you know, where you want your boat painted? ).

The owners told me that I could not use engineered lumber in a commercial building as it does not meet the fire code. When I asked why I could use it in a house ( they use it like water up here ) they said they had no idea.

Anyone have an idea what they mean?

I am curious as I am in the steps of planning for some home modifications and they all depend quite heavily on engineered lumber. Hate to find out I made a fire trap.

Thanks to all for your help.

-dan

[Richard]

Could they mean "I don't know and I'm just guessing"? I am in Georgia and I see plenty of buildings with laminated beams supporting the roof. Very common practice- restaurants, churches, you name it.

Richard

[Old guy]

There are all kinds of commercial buildings, ranging from barns to multistory office buildings, and the building code reflects the usage, hazard, and occupancy of the buildings.

Basically, wood burns, so it is not allowed in large, multistory buildings, where there are hazardous uses, or lots of people.

A paint shop for boats might be a hazardous/flammable use.

A house isn't. It's assumed that the occupants are familiar with the way out, and can get out in a few minutes, so if the structure burns through in half an hour, there isn't a loss of life.

That being said, I understand that fire departments are not crazy about truss joist or open web floor trusses because they collapse sooner than solid wood.

A solid, laminated beam shouldn't burn (or fail) any faster than a solid wood beam of the same size.

If you have more questions, pick up the phone and call the local inspector. They'd much rather answer questions ahead of time than tag the house because of later problems.

Old Guy

[EXT]

While I doubt that the owners knew all aspects of the building code, a commercial paint shop must meet certain requirements. Involved will be explosion proof electrical system, exhaust and makeup air fans, and fireproof structure. I doubt that wood would be allowed unless well protected from flames.

[Pat Barber]

Are you talking about "plastic" lumber by any chance or "engineered" sections like glu-lams and floor trusses ???

Dan wrote:

[Dan]

Glu Lams and trusses. The bits we wanted to use resemble I Beams but made out of wood ( kind - it looks more or less like a composeite material )

Pat Barber wrote:

[Lew Hodgett]

RE: Subject

A common misconception is that structural laminated beams will fail sooner than steel trusses.

Tain't necessarily so.

Wooden beams will char on the outside but but are basically self extinguishing and maintain the bulk of their strength.

OTOH, steel beams lose strength as they get heated, which starts somewhere around 700F-800F.

Remember the fire at McCormick Place Exhibit Hall in Chicago.

Don't remember what started the fire, but the steel trusses got too hot, then gave way, and the whole place came down.

Can't remember, but don't think they rebuilt with steel trusses, at least not without some serious modifications.

Lew

[Lew Hodgett]

This applies to laminated beams.

Don't have any idea how wood chips and glue construction would behave under those conditions.

Lew

[Pete C.]

But that can't be, all the 9/11 conspiracy loons claim steel has to melt to fail and a Jet-A fueled fire in a convection chimney scenario can't get that hot... ;)

[todd]

Yeah, well, they'd be wrong. Structural steel becomes spaghetti wayyyy below melting point. This is the reason that structural steel members have fireproofing installed. Unfortunately, spray-on fireproofing doesn't work as well after it's been impacted with a 767.

[Dave Hall]

Sometimes local code is just based on politics. Not 100% sure that it is still true, but at least as far back as the late 1980s it was the law in Allegheny county, PA (home of Pittsburgh and many steel mills) that houses had to use a steel beam for its main foundation beam support. Glue lams and other wood based product were not allowed. Everyone in surrounding areas used laminated beams, but I guess that the steel industry and the steel unions were not quite as powerful as they were in Allegheny County.

I guess the point is that we don't know what the local code is wherever the OP lives.

Dave Hall

[M Berger]

Are you talking about BCI joists? They're great -- very strong, and you can run wires and pipes through them easily without sacrificing the structural integrity.

I doubt they're as good as glue lam beams > Glu Lams and trusses. The bits we wanted to use resemble I Beams but

[Pat Barber]

Local codes would decide everything. It would pretty wierd to "not" use glu-lams but I have seen strange building codes posted here.

There would be damn few building in the USA that are built today not using a truss of some sort. Glu-lams are almost universal at buidling sites.

"Commercial" build> Glu Lams and trusses. The bits we wanted to use resemble I Beams but