BS: building collapse - how?

Subject: BS: building collapse - how?
From: GUEST,crazy little woman
Date: 30 Jun 06 - 10:50 AM

There's a small town near Kansas City called Clinton, and a couple days ago, the Elks Hall, a three-story brick building finished in 1880, collapsed almost instantaneously, trapping 9 men for many hours and killing one. Emergency workers from many miles around were called in, and experts came from the Kansas City Fire Department to carry out the delicate job of rescuing the trapped men.

(You can read news reports by searching for Clinton Missouri Elks on Google, but I don't know how long the stories will remain available once the main events are over.)

Federal investigators are working now to see what happened, but answers are going to take a long time, I'm sure. In the meantime, the question is preying on my mind. How could such a thing happen? These old buildings are usually so solid! Anbody have any knowledge about this kind of thing?

Subject: RE: BS: building collapse - how?
From: John MacKenzie
Date: 30 Jun 06 - 11:10 AM

If rooms in a building are opened up by knocking down an internal wall to make them larger this can be the result.
If this wall is load bearing then it is necessary to insert a load bearing joist in its place, this is known in the UK as an RSJ [reinforcing steel joist] If this is not done or is done badly, like the end of the RSJ is not well secured, then the building can collapse. In a case like that it tends to implode, the inside floors concertina, and then the walls fall in on top.
Subsidence can also cause the collapse of a building, in fact many things can, but the removal of internal walls is the most common cause of cases like this.
Giok

Subject: RE: BS: building collapse - how?
From: Paco Rabanne
Date: 30 Jun 06 - 11:31 AM

Wrong! RSJ stands for ' Rolled Steel Joist', which CAN be used as a lintel.

Subject: RE: BS: building collapse - how?
From: GUEST
Date: 30 Jun 06 - 11:56 AM

Termites? Wood floor joists can deteroriate over time (assuming) and many times were an integral part of the support for the outside walls. Did the entire building collapse?

Subject: RE: BS: building collapse - how?
From: Bobert
Date: 30 Jun 06 - 11:59 AM

Well, I just completed a renovation of an 1827 3 story building in Winchester, Va. and what John says is correct... This particular building, like the one in Clinton was a disaster waiting to happen... In 1933 a stiarcase had been moved to open up the first floor for commercial space... Problem is that a wall supporting one side of the stair case was removed and it was, ahhhhh, a danged bearing wall... Over the years the massive 10 inch by 14 inch girders were asked to carry more weight than they we engineered to do and thus, over the years developed cracks, and the building slowly but surely was fallin' in on itself...

What I had to do was dig a footer in the basement and with a combination of lollie-columns (posts) and LVL's (beam) running beneath these girders from the posts into chizzeled out pockets in the brick walls, rebuild the basic structure of that portion of the building...

Oh, yeah.. The fun part... The building had to be slowly jacked up the 2 2/4 inches it had fallen in... I learned to do this kinda stuff while working for a company that did renovations in Richmonmd but it's always a little scarey, non the less, when the ol' gal starts poppin' and graonin'... It can't be done in one shot... Might of fact, I go up there every 3 months and give it a little tweakin'...

There are other factors which might have contributed to the collapse related to the foundation but I suspect its in the framin'...

Keep us posted (pun intended)...

Bobert

Subject: RE: BS: building collapse - how?
From: open mike
Date: 30 Jun 06 - 12:49 PM

the fellow who went up to the floor above (3rd?)
had gone up there to practice a speech. He was the
one who perished, from what i heard. The others on
the floor below (2nd?) were all rescued.

I can see how if the people were dancing it might put
extra stress on the bldg. Like that thing that happens
when soldiers march across a bridge--they "break cadence"
so the waves from their marching do not amplify and damage
the structure.

Subject: RE: BS: building collapse - how?
From: JennyO
Date: 30 Jun 06 - 01:11 PM

I found this article here.

Engineers from the federal government and insurance investigators say faulty renovation work may have triggered the collapse of the three-story Elks Lodge Monday night.

So it sounds like Giok and Bobert are on the right track.

Subject: RE: BS: building collapse - how?
From: gnu
Date: 30 Jun 06 - 01:21 PM

Bobert. I find 1/4" per month works well, as a rule of thumb. Of course, each job is different, so, safety is the rule. Did you locate all the plumbing and electrical that might be affected by jacking?

As for the original post, like Giok says, there are many things which could cause a collapse, singualarly or in concert. Most often, it is human error, whether that be lack of knowledge, simple error, maintenance neglect, or other. I've seen people do some pretty stupid things in original construction and during renovation.

Giok mentioned subsidence. I just investigated a structural failure in a building that was caused by the exact opposite. We had a tremendous amount of rain this spring. A huge apartment building was built last year on the lot adjacent to the building which suffered the failure. The apartment building was downslope on about a 4:1 grade. The drainage of the heavier than normal rainfall was impeded by the apartment building. This caused a clay lense under approximately 1/4 of the failed building at one upslope corner to swell, providing the strain which caused the failure. I analysed boreholes adjacent to the failure and beyond the zone of influence of the apartment building... oops... sorry.... I'll just sum it up...

Without getting too detailed, here it is in a nutshell. The owner of the apartment building does not like me. Neither does his lawyer, or so he bullshits, er, says.

Ah, water. Life itself. If it wasn't for water, geotechnical engineers would die of thirst.

Subject: RE: BS: building collapse - how?
From: Bunnahabhain
Date: 30 Jun 06 - 01:23 PM

The reports I can see don't mention dancing, but I think they're all AP, or rewrites thereof. Dancing can collapse buildings, but you'd have to try really hard.

A few years back, we were going over choreography in a upstairs hall, and brought a 10 foot circle of the ceiling down in the room below. As this was thick Victorian plaster from a ceiling about 20 foot up, not a good thing rto be underneath.

We had been assured that the room was used by line-dancers twice a week, and this had never happened before. We must just have been in time better, and dancing at the correct tempo to hit a resonance frequancy of the floor... I think the point I was trying to get to is that there are likley to be some warning signs if some you're doing is about to collapse the building.

Subject: RE: BS: building collapse - how?
From: John MacKenzie
Date: 30 Jun 06 - 01:49 PM

Sorry Ted, but I'm not a member of the building trade like what you are.
You knew what I meant though!
Giok

Subject: RE: BS: building collapse - how?
From: Les from Hull
Date: 30 Jun 06 - 02:15 PM

I was downstairs at the Friary in Beverley during this years Folk Festival. Chechelele were running a workshop (they do African music) and they were doing a warm-up which consisted of everyone jumping and shouting at the same time. The Warden of the building said that the beam below them moved about an inch, and went running upstairs to ask them not to do it again! They did the rest of their movement-based stuff outside, including a Rain Dance (which worked!).

Beverley Friary is 600 years old.

Subject: RE: BS: building collapse - how?
From: Barry Finn
Date: 30 Jun 06 - 03:10 PM

Another contribiting factor that can cause a collapse is drainage. Roofs will only hold the weight that they were designed to hold. That includes dead weights or/and snowloads. If a roof isn't designed to shed water over the edge then it requires an internal drain system. Some roofs is designed to direct the water flow over the edge by way of scuppers & sometimes these scuppers are install in parapet wall. If scuppers or drains become clogged then the weight of a flooded roof can easily cause a collapse.

Another cause can be by water entering through what's called the "weather envolope". This would be the roof, wall & roof insulation & ventilation, brick or wood or other types of siding, windows, flashings. Water will cause structural damage if left alone long enough.

Barry

Subject: RE: BS: building collapse - how?
From: GUEST,crazy little woman
Date: 30 Jun 06 - 06:15 PM

Thanks for all the insights. There was no dancing going on, merely a dinner.

I'm impressed by the knowledge y'all have.

Subject: RE: BS: building collapse - how?
From: Bunnahabhain
Date: 30 Jun 06 - 06:41 PM

We have many experts on many things here. Many of the things we comment on we are not experts in, but have some knowledge of the subject, are intelligent( well, mainly, not sure about me...) and not likley to keep opinions to ourselves.

I'm not trying to be mean about those here who have real experince of, in this case, building/structural/geotechnical engineering experince, just stating a fact of the 'cat

Subject: RE: BS: building collapse - how?
From: The Fooles Troupe
Date: 30 Jun 06 - 07:33 PM

Some of you guys may be interested in this.

My neighbour (a STRANGE lady)... has dug a massive channel, nearly a foot wide and about 2 feet at least deep, along the boundary fence line. My house is above hers on the gentle slope, and we have red clay sitting on shale (paid for soil tests years ago). Our houses are about 10 feet apart.

We cycle thru drought and flooding rains in Australia, ya know!

A few years ago, I fund her at midnight (during a wet period) praying to the Goddess of the earth chanting 'please drive this evil from my land' - in order to stop the water flowing down the hill thru the soil... she then finished this little ceremony complete with lit candles and sprigs of herbs tied to the fencposts, with a rousing version of Onward Christian Soldiers...

Incidentally, she has also excavated about 1 ft down around her foundations (brick and concrete pillars max 2 ft deep - and around the front corner on my side, she has undermined totally one corner, where she has also neatly installed an extra down-pipe from the gutter - which was overflowing and dumping water thru the roof into her house...) which hold up a weather-board timber frame house about 40-45 years old, because she wanted to 'keep the foundations dry'...

She has written to me complaining that my watering my garden bed along the boundary was causing water damage to her foundations, as she can see cracks inside her house (fibro) walls... btw, she has stripped off the top 2 feet of topsoil as well as the contents of this trench and spread them on her garden beds. Also her house has a 'corrugated fibro' roof - nice and brittle by now I should think...

We are now in a serious drought situation, and soil is moving...

My question is, based on you guys technical experience, is just when should I sell the tickets for the big event of watching her house collapse?

:-)

Subject: RE: BS: building collapse - how?
From: The Fooles Troupe
Date: 30 Jun 06 - 07:36 PM

Oh, forgot to add...

"I'm not making this up you know..."

Subject: RE: BS: building collapse - how?
From: Naemanson
Date: 30 Jun 06 - 07:52 PM

Way back in the mists of time, when I was in college, I had a job tearing out the interior of one of the campus buildings to prepare it for renovations. To give you an idea of how old the building was we found newspapers that had been used to insulate the walls. One of the articles was a story of the new military installations built to protect migrants from the Indians attacking them on the Oregon trail!

Anyway, in one corner we tore out the interior sheathing to find that the only thing holding the corner together was friction. The exterior wood of a recent addition (less than 75 years old) was resting on the exterior wood of the older part of the building. At some time in the past someone had removed the studs tying it all together! Once again, a disaster waiting to happen.

The school? Now it is the University Of New England in Biddeford, Maine. The building? It is the central building of the medical college.

Subject: RE: BS: building collapse - how?
From: Jim Dixon
Date: 30 Jun 06 - 08:09 PM

A brick wall can collapse if if hasn't been tuckpointed regularly, i.e. every 25 years or so. The mortar cracks, letting in water, which causes further deterioration. Add a regular freeze-thaw cycle and eventually the whole thing comes down.

Subject: RE: BS: building collapse - how?
From: Bobert
Date: 30 Jun 06 - 08:17 PM

gnu,

Fortunately, we knew we were going to replumb and rewire the entire building once it was stabilized and we'd done what interior framing we had to do so we didn't have to concern ourselves with any mechanical stuff... And we were workin' with a temp. electrical services that we wired so we knew where those wire were...

As fir the 1/4 inch, because we had lollie columens and LVL's running the entire three floors off a common footer and had demo'd out all the plaster and needed to get to work on alot of framin' I pushed the envelope and took her an inch over a two day period and then another 1/2 inch over the next 3 or 4 days and then went to incrimentals...

By the time I did the initial jackin' I understood what the ol' gal was all about and had had engineers figure the LVL's and had to get her up so we could be doin' other things...

But let me tell you that there were some scared folks in the basement with me the day we started jackin' and one of 'um looked down at me with my 20 ton jack and said, "Man, you are f**kin' crazy"...

I told him that if he couldn't take the heat to get the heck outta the kitchen... He stayed and will probably one day tell his grand kids about the old hippie who tried to kill him... Haha...

It was a blast... Heck, I was gettin' paid good to do it but that day I would have paid ther buildin's owners for the thrill of ther intial jackin'... I swear I would... Very exileratin' to have figured out the problems, come up with the plan, draw it up on paper and have the Winchester town engineers approve it, set the columns and the LVL's and so the actual lifting was the smoke from the candle on the icing on the cake... Sho nuff...

But the best part about it??? The old hotel that I bought and will start renovating soon has some structural issues as well... Okay, not as bad as the Winchester building but a few thrills, non the less...

Cowabunga!!!

Bobert

Subject: RE: BS: building collapse - how?
From: GUEST,pattyClink
Date: 30 Jun 06 - 08:29 PM

Foolestroupe, may I suggest you have the local building inspector (or a friend of a friend who is a civil engineer, soil tech, or engineering geologist) take a look at this mess ASAP? If your house is higher than hers, adjacent to an exposed cut bank, and only 10 feet away, then she is undermining your well-being as well as her own.    If you don't want a big confrontation right now, perhaps you could get an inspection some day she is away from the property.    It's really hard to fix foundation damage once it's done--much cheaper and easy to remediate if you act in time.

You expert may just tell you all the digging will wind up harmless to you, but I kind of doubt it. You are likely to need an authority to get her to face reality and get this fixed fast. Somebody knowledgeable and patient can explain to her that some nice French drains could allay her goofy fears without wrecking two pieces of property, for example--and if that doesn't work, court orders are nice too. And beware her writing letters. That's a setup to her getting ready to sue, crazy or not.   You want to get it on paper and/or film that she's doing this dumb stuff long before you become the defendant.

Subject: RE: BS: building collapse - how?
From: The Fooles Troupe
Date: 30 Jun 06 - 09:06 PM

pattyClink

Thanks for your genuine concern, but:

It's s very gentle slope, almost invisible to the naked eye, but just enough for normal easy drainage. There is about 10 feet between my foundations and the fence line.

"get her to face reality and get this fixed fast"

Hahahahaha!

"beware her writing letters. That's a setup to her getting ready to sue, crazy or not.   You want to get it on paper and/or film that she's doing this dumb stuff long before you become the defendant. "

I am aware of that. Much has already been documented, on paper and photos.

However, she has put herself well out of the game. I suspect from the tone of her letters that she has lots of 'street smarts' from years of this sort of bullying (she seems to have some of the terms right, but wrongly used, for example - I suspect that she is just recycling what has been used against HER in the past...), but she's an amateur at that game - I spent 30 years on the end of major bullying at work by a team of experts - some of them documented under treatment for psychosis at the time! (now I am on a disability pension due to some of the long term effects! may have to go back on the 'happy tabs' again soon!).

All the appropriate authorities were contacted early on. No Council permits are needed for any excavations on her property under one metre in this circumstance. I have established that nothing I have done has contributed to any excess water flowing onto her property, indeed I have installed concrete 'garden bed edges' that in fact impede the surface flow of water, and encourage it to be absorbed on my property. My main concern was that her excavations might be drying out the soil on my property, causing me concern about my concrete post foundations, but so far, there is no evidence of that - no cracking of plaster due to movement thereby, etc.

She has refused to give me her name - in front of the Police, as she was trying (when I had called the Police to get her to stop jumping the fence and damage my plants several metres inside the boundary line!) to claim that I was stalking/harassing her!

So as to her writing me allegedly anonymous letters which were self contradictory, and highly confused... My written answers (as well as documenting the facts) to 'the owner of the property' expressed concerns over the mental health of 'the anonymous resident of the property who refuses to give me her name', and as time went on I mentioned therein that I had been contacting the Mental Health Dept over the actions of this person, have largely destroyed her credibility... the letters stopped some time ago...

She did try 'taking me to mediation' - an official process, but I'm not that stupid, as any documentation presented to that body is then by the Law which governs that mediation body, unable to be used in any subsequent Court Case on the matter... :-)

I suspect why she has also been stealing soil inside my property line (from under the fence) is due to the fact that she made so much fuss with her other neighbour about replacing their common fence (after she slashed all THEIR plants!) that the line was re-surveyed, and the fence moved nearly a foot from the original fence position onto 'her' land, thereby almost obstructing her access to her side stairs... :-)

The whole neighbourhood is well aware of her, and her clever antics such as wandering around after midnight on other adjacent properties stealing things like rocks, etc... :-) Everybody now has locked fences and gates...


Wanna buy some tickets?

:-)

Subject: RE: BS: building collapse - how?
From: Bunnahabhain
Date: 01 Jul 06 - 06:10 AM

Well, there's nothing like good old fashioned crazy people to make life interesting, like it or not. But why do they have to live next door?

You can always try an less logical approachThis place is a little older than her house, is timber framed on Brick foundations*, sitting on a clay slope, and hasn't fallen down, rotted, or needed the panama canal around it for drainage....

When it rains, depending on the local geology, she may have just broken through the nice impervious clay that was capping off the shale aquifer, and have created a spring just above her house ....


* or possibly stone. they won't be more than a few feet deep either way.

Subject: RE: BS: building collapse - how?
From: DMcG
Date: 01 Jul 06 - 06:15 AM

If this wall is load bearing then it is necessary to insert a load bearing joist in its place, this is known in the UK as an RSJ [reinforcing steel joist] If this is not done or is done badly, like the end of the RSJ is not well secured, then the building can collapse.
When we were looking for our last-but-one house, we looked at a house where they had taken a wall down and fitted an RSJ ... but only one end was supported. The other end stopped about a foot away from the opposite wall.

Subject: RE: BS: building collapse - how?
From: The Fooles Troupe
Date: 01 Jul 06 - 07:26 AM

So you DIDN'T buy that one? :-)

Subject: RE: BS: building collapse - how?
From: gnu
Date: 02 Jul 06 - 05:23 AM

I just remembered a good one. I have a pic of lovely cottage with a fresh snow covering the porch and ground. It's a pretty scene. If you look closely through the open front door, you can see a wood stove... covered in snow with debris around it. All that was left standing was the front wall.

It took me about a minute to spot the cause of the roof collapse. The gusset plates on the roof trusses were pressboard (chipboard, other names). All it took was a bit of freeze-thaw and a medium snow load.

Subject: RE: BS: building collapse - how?
From: The Fooles Troupe
Date: 02 Jul 06 - 09:17 AM

Most Aussie 'bungalows' (stand alone single houses) of the period in this area are single level wooden post and beam hand built.

Subject: RE: BS: building collapse - how?
From: GUEST,redhorse at work
Date: 03 Jul 06 - 08:42 AM

"These old buildings are usually so solid!" Er...not necessarily. Leaving aside the issue of what are suitable foundations- views have changed over the years - there were probably as many incompetent or crooked builders in days gone by as there are today (and there were fewer building regulations to help them to keep honest)

When I bought a 100-year old house in the 1980's, I had to take down a leaning boundary wall. 4 1/2inch wall with butresses every 10 foot, looked nicely built. When I took it down , the wall was properly founded, but the buttresses didn't go below ground level - in fact you could still see the remains of dried grasses under the bottom course of bricks. Miracle it lasted as long as it did. After that I started looking at "Victorian craftsmanship" with a rather more jaundiced eye. When you're looking for it you can find just as many bodges in an old house as a new one

nick

Subject: RE: BS: building collapse - how?
From: The Fooles Troupe
Date: 03 Jul 06 - 08:52 AM

In King Tut's tomb, it was found that the beautiful gold covered carved wooden screen, which was designed to face the four compass directions, each with a different motif, was installed 90 degrees out of alignment, and must have jammed during assembly, so had been given several very heavy whacks with a large blunt object, marking the finish!!!

The quality of workmanship has not changed, especially when in a rush for time, and the boss is not looking...

Subject: RE: BS: building collapse - how?
From: Bunnahabhain
Date: 03 Jul 06 - 09:08 AM

When you're looking for it you can find just as many bodges in an old house as a new one

Not true! In a modern house it's a bodge, in an old one it's a quaint, unique, period feature.....

Subject: RE: BS: building collapse - how?
From: Rapparee
Date: 03 Jul 06 - 11:23 AM

My brother had his living room redone -- and they found that a load-bearing wall had been taken out and replaced by a single 4 x 4. It had a 2.5 inch sag in it. This has now been corrected, the upstairs floors are level, and the place really looks nice. Even better, the ceiling won't fall in, surprising both those in the living room and those in the bedrooms!

Old materials can deteriorate, especially if they were not of the best quality to start with. And "renovations" can be disasterous:   sandblasting bricks, for instance, is a lousy idea -- first it takes off the protective patina, exposing the soft interior to the weather, and then it blows away chunks of the bricks if the blaster isn't very careful.

If you're going to renovate either know what you're doing and take the time to do it right or hire a a professional.

Subject: RE: BS: building collapse - how?
From: gnu
Date: 03 Jul 06 - 03:55 PM

Rap is right. And, Pro = Architect or Engineer. Not a contractor with years of experience. Not a Home Inspector (trust me... even the certified Home Inspectors with lots of experience are NOT Pro's). Not a draughtsperson. Not even JC himself, THE Master Carpenter. Pay the money and get it done right. I've seen too many people with sad faces when I tell them they are out thousands of dollars.

Subject: RE: BS: building collapse - how?
From: Bizibod
Date: 03 Jul 06 - 07:42 PM

We bought an Edwardian house where a load-bearing wall had been removed and a "decorative" railway sleeper from Cotgrave colliery had been installed rather than an RSJ.When we removed it, having supported the upstairs wall with acro props ,it was evident that the bricks of the bedroom wall were gradually shimmying in a downward direction between the overlying plaster and wallpaper finish !
This was the work of the same guy who "built" a chimney breast in front of the original one,(more railway sleepers )some bricks and lots of woodchip wallpaper which he furnished with a "log -effect" gas-fire at waist height.It had obviously never been used , because had it ever been lighted the house would have caught fire !
A little knowledge and a lot of enthusiasm is a dangerous thing !

Subject: RE: BS: building collapse - how?
From: Rapparee
Date: 03 Jul 06 - 08:01 PM

The building I work in was built in 1907-08 (groundbreaking in '07, dedication in ''08). I need to replace the roof (cedar shingles, and it's on the National Register so cedar shingles will be the replacement) and I thought to get any tuckpointing, etc. done at the same time. The local masonry specialist for the State Historic Preservation Commission and I went up on the roof to look at the brickwork -- and he put a hand on the south gable, which is brick. It moved about an inch!

He asked me if the wall had moved, I leaned gently upon it, and sure enough, it moved! Since is wasn't love, we had a problem!

Turned out that the gable wall, composed of two thicknesses of brick, was leanining inwards and could very well fall. If it fell it would fall through the ceiling onto the Administrative Assistant, who would have been quite put out, to say the least.

I offered her a hard hat, offered to put Caution tape around her desk, and things like that, but she insisted that repairs be made.

We made them, of course. And it was money VERY well spent!

(Why the south gable wall? Because the weather comes from that direction, up the valley.)

Subject: RE: BS: building collapse - how?
From: GUEST
Date: 03 Jul 06 - 08:23 PM

The Elks' building had had renovations done on it a few years back according to one of the news stories. Ten to one they messed with a load-bearing wall.

Subject: RE: BS: building collapse - how?
From: Deckman
Date: 03 Jul 06 - 09:40 PM

I've been in construction ALL my life, and I love it. For the last 20 some years I've focused on decks. Yes ... I'm "The Deckman." I'm the fourth generation builder in my family, and my 39 year old son is now the fifth generation.

I am often astounded, and frightened I might add, at some of the construction situations I find myself in. I well remember one deck I re-built proabably a dozen years ago. It was a second story deck and was literally hanging off the house at a 45 degree angle. The home owner, customer, opened the sliding door and bounded out there to show me what he wanted me to do. I refused to step on it.

After a succesfull re-build, he shook my hand, paid me, and told me that he was a "structural engineer" at the largest state University in Washington state.

After all my years of construction experience, I'm still very quick to pick up the phone and call Kristin ... my "structual engineer." She has saved my butt many times. And, here on the West Coast, the recent earthquakes are causing us to re-think our earthquake codes. It's almost a full time job just to keep up with the building code changes.

When bad construction fails, people die. I know. I've had to testify twice as an "expert witness" in casuilty claims. Not nice. CHEERS, Bob

Subject: RE: BS: building collapse - how?
From: Rapparee
Date: 03 Jul 06 - 10:10 PM

When I see how buildings, especially houses, are constructed today I want to cringe. When I see how badly Joe Homeowner can f*ck it up I want to choke him. I'm still rectifying mistakes and stuff made here, and we've put over USD 16,000 into the house, most of it before we'd move in. And this house has "traditional" construction: angled boards holding the studs together, stuff like that. And then the grease fans exhaust into the attic area -- and we don't use the grease fans.

I'm waiting for a wildfire the hit the hills immediately east of me: there's USD 800,000* houses up there and only one (1) street in or out of the area. At least I have two ways to evacuate if it's needed.



*Pocatello price. Double it for Salt Lake City, triple it for Denver, and multiply by 5 or 6 for DC, San Franciso, LA, or New York.

Subject: RE: BS: building collapse - how?
From: Deckman
Date: 03 Jul 06 - 11:28 PM

YEP! Bob

Subject: RE: BS: building collapse - how?
From: Bunnahabhain
Date: 04 Jul 06 - 08:55 AM

Every time building type stuff comes up round here, one thing stands out to me. In the UK, most homes are built of blockwork of some kind: stone, brick or concrete. In the US, most of your references are to timber framed houses. Is this actually true, or just the way stuff reads?

Every time we see report from a US hurricane, we see pictures of houses being blown away, that look as if cardboard is the main construction materiel. I can understand an aversion to heavy masonry in earthquake zones, but not the rest of the country. Any thoughts?

Subject: RE: BS: building collapse - how?
From: The Fooles Troupe
Date: 04 Jul 06 - 09:15 AM

Many Aussie houses (especially in the more northern parts) prior to the 60s were old fashioned post and beam timber (usually weather-board or chamfer-board clad) construction. But then concrete slab based construction (with prebuilt roof trusses) became more popular (read cheaper), and nowadays steel framing is not uncommon as well. Also differing construction styles are used, nowadays huge slabs of plywood are often used to provide torsional rigidity to the walls.

Masonry construction used to be the hallmark of the southern side of the continent, being based on 'traditional European/English' - also double brick or brick clad wooden framed houses were more the preserve of the more well to do, especially in the more northerly end.

My uncle the plumber said in the 60s that 'the (corrugated iron) roof held the (weather)board walls up.

Funnily enough, provided the roof trusses and beams are strapped down, and if roofing screws are used instead of the old fashioned 'lead head' nails, then Aussie houses can easily be rated quite high for cyclonic winds, as indeed revised building regs after Cyclone Tracy hit Darwin, the main problem being that legacy housing is usually not retrofitted to the higher 'tie down' standards.

Of course Cat 3 used to be the main high rating - Cat 5 rating is MUCH more expensive to construct, also involving architectural concepts such as taking care of large overhanging eaves, etc.

Subject: RE: BS: building collapse - how?
From: gnu
Date: 04 Jul 06 - 10:59 AM

Bob... I've seen the odd engineer who did a job that he thought he could do but couldn't. Usually it's a money thing. Ain't it always?