Boise "I" Beams

[John]

Boise USA made 420mm wooden composite "I" beams were use in a new school in Milton Keynes, England in 2003 - Giles Brook, Tattenhoe, Milton Keynes. A batch of them failed entailing the closure of the school. Portakabin classrooms have been installed on the playing fields and the pupils are moving into these until the beams are replaced and the school building back in order. Ceilings and florrs have been ripped up.

A whole school has moved after first bussing the pupils around the city to spare classrooms in other schools. Now into temporary portakabins. Serious stuff.

The problem is a manufacturers failure of the beams. Boise sent over a techie for the USA who agreed with TRADA an independent testing house specialising in timber construction and the Building Research Establishment. The failure was the laminated flange coming away from the OSB web.

The builders narrowed the failed beams to a particular day - they are date and time stamped and which team made them - the builders said all beams made on that day will be replaced. TRADA testers narrowed it down to 10 minutes. This is the 10 minutes when the two types of glue did not mix properly in the beam making process.

Within this 10 minutes about 1000 metres of beam estimate to have been made with over 700 metres going to the school in England. Now Boise have to track down where the other 300 metres of beams went - if they can. Could be to the UK, US or Canada or wherever. The date of manufacture is 31 Jan

2003. So if you have 420mm Boise beams check the day of manufacture as they will have a high risk of failure.

Who pays for the replacements and the extra cost of the temporary school will be determined by lawyers I'm sure. The council is not using wooden composite "I" beams any more in new builds. Enough is enough for them.

Doing a Google on Boise they have a poor environmental record and poor at other things too.

[RicodJour]

There's no need to Google the fact that using wood beams in what should be a masonry/steel structure is a poor choice. There's plenty of blame to be assigned to the code officials, architect, engineer and school board as well.

R

[Bob Morrison]

I agree. Schools should be made of non-combustible construction.

[Pat]

[Don]

"John"> wrote

I always thought that was a peculiar way of doing that, especially considering the amount of stress thats on the bottom chord of floor joists.

My birfday!

[Don]

Should? There is no reason to NOT use wood if all other issues are factored in and compensated for. But I do agree that here in the US it seems that no money spared in the construction of gov't buildings.

[Don]

I've used trusses constructed of pressure treated lumber and stainless steel plates when combustion was an issue. Not to mention the code issue of sprinklers in attic/contained spaces. We all now know what *can* happen to (exposed) steel when subjected to extreme heat.

[John]

Yep. One reason why steel is in question.

[Ken S. Tucker]

One problem is demographical, young folks move in to a new area and have lots of babies, and then need schools, then the neighbourhood becomes fogy and the schools 1/2 empty and perhaps even redundant, in some places that could be 10-15 year cycle. Ken

[John]

The laminated flange was fine, it was the OSB web that runs in a groove in the flange that came away.

The laminated flange is supposed to be stronger than raw timber and doesn't shrink (well within 1% or whatever)

Check the date stamp on your beams then. :-)

[John]

Yep. My school lasted 20 years. It was very well designed and built. In hindsight they would have built a less expensive structure.

[RicodJour]

Yes.

There's no reason to make stair steps all the same size if people paid attention ALL of the time.

You lived in Germany, right? I would suppose you were on the base most of the time, but I don't know - maybe you had a similar experience/observation. When I lived in Italy for my junior year abroad (no, I didn't wear dresses, Don), in the heart of Rome, I heard exactly two fire engines. Two. In a year. I hear more than that in a week where I live now, and that has far newer buildings and a far lower population density. Why would that be? Oh, right. Masonry buildings that don't burn.

Agree? Agree to what? No one mentioned your personal pet peeve.

R

[Ken S. Tucker]

Maybe the answer is to get a formula for a temporary school (aside from little portables) that's nice but can be disassembled to modular mobile pieces, then reconnected or stored, that's still a bit classy. Ken

[Don]

I wonder why temporary classroms are constructed of wood when EVERYBODY knows steel is so much better?

[Don]

"John"> wrote

It sounds like the glue itself is where the problem lies. Are you saying the web pulled loose from the (flange) bottom/top chords, or that the web (OSB) disintegrated? To me it seems like a lot of pressure is being generated downward and glue alone is what holds it together and I find that sort of strange. How long was the span, and how tall were the joists, and how were they spaced (center to center)?

[DanG]

Of the 62 we own, there are none framed in wood. I know some of the neighboring districts do have some, however.

Permanent structures for E usage require non flammable construction in BOCA and IBC. These are the codes past and present here. ___________________________ Keep the whole world singing. . . . DanG

[RicodJour]

Is that like a CDROM?

If masonry construction is so expensive, how come masonry construction is so common in apartment developments and malls? It's not like the developer is intentionally trying to piss money away. Code obviously is a factor, but it's a cost/benefit analysis that rules the day. If the apartments were temporary, or meant to be mobile - like temporary classrooms - of course they'd be wood or steel stud.

Your pet peeve blinds you to certain issues. It makes it difficult to talk to you sometimes because you have that certain pathway burnt into your brain. Google the energy usage of a baby's brain as opposed to an adult brain. You'll see what I mean about the burnt in pathways.

You have made it clear that you feel public schools are anathema. You convey the message that they should not exist. That viewpoint inevitably leads to the conclusion that any public school expenditure is a waste of money. I disagree. There's no argument that gobs of money are pissed away. But making a long-lasting building that is inherently safer would seem to be money well spent. Seems to me the money is wasted in other areas.

You were in FL. Were there any public shelter buildings that were wood framed? How about in IN? I have yet to hear anyone say, "The twister's coming, Ma! Let's hightail it over to Jeb's. He has wood trusses and engineered wood joists!" It's not just about fire.

R

[Matt Whiting]

There is nothing wrong with wood beams. Why do you think they should be concrete or steel?

Matt

[Matt Whiting]

Combustion is an issue, but so is yielding of steel beams in a fire.

Matt

[John]

Yep. They use two and mix it directly before applying. They use two large vats, It flows in and is mixed to the correct percentage and flow. Something went wrong here. When mixed the surplus glue is amber coloured, when not mixed correctly it is white.

Yep. the bottom.

The web was fine, just the glue.

420mm in depth. The span I'm not sure of. However it was in an area were there was a lot of stress, however the beams should have easily coped.

What went first was the joint where the OSB web meets another section of OSB. This went because the flange was not securely glued into the web. The racking had gone. The vertical joint between the OBS pieces moved and the whole integrity collapsed pushing out the bottom flange. It "may" have been the case that is the OBS to OSB joint was in another position the beam would have survived. The OSB to OSB joint was in an area near to the bottom flange where the glue never took because it was not mixed correctly.

400mm centres

Boise, have a big problem in their manufacturing process. A good system would have picked up that something is wrong - they are all computerised with monitoring these days.

How many times has this happend in the past, and beams are fitted being a ticking time bomb?