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Not true. The floor joists were not I beams but webbed trusses and they were pinned to the outside walls. There is a lot more to the collapse of the towers than the attachment of the flor joists. A major factor was the lack of fire retardment material on the joists and the fact that the fire barriers surrounding the internal shaft was obliterated by the force of the impact of the planes.Quote:
Originally Posted by Marc
I apologize now to anyone that this may touch a nerve with.
Fellow Woodies
Have read the whole thread and have come to the conclusion that it may be not a bad idea use the gal metal frames commonly used these days. Son in law built a nice house using a 5 bedroom 2 bathroom kit from a company in Penrith and every thing was supplied down to the last bolt / screw. The house has been up for five years with no faults so it has proven to be a good way to go.
Kind Regards Mike. ;)
The best term, i herd at uni to discribe this type of costruction, "lean construction"
hey there is nothing wrong with the product, it meets all the stds etc, but the computer that spits out the beam sizes and exceptable spans choses the one that just exceds the requirements. IN the old days we would get the span table out and select the required beam then go to the next size up to be happy, so we are effectively over engineering by 50% but now its all spot on. I know of frame and truss plants using un-structual grade framing and even F5 where when we do on site cut we do not go under F7 / MPG10.
The solution is when building your own place over desighn the beams, this will aviod the problems faced by project homes such as plasterboard cracking along the top from the floor joists flexing, (BUT the flex is within the allowable movement)
There is no way that in 10 yrs time any builders would think about doing extenstions to project homes as you would have to go all the way though to build from the footings up to take the extra loads.
Gaz I dont think too many people would be extending the MacMansions anyway.
There is an old saying, "it is better to remain silent and appear ignorant than to open your mouth and remove all doubt".
The hardboard web in the I-Joists (8 mm not 6) are fully long term tested under all likely conditions including the effects of moisture. No manufacturer is going to put a structural element into a dwelling without considerable testing and confidence in the materials.
There is thirty (30) year history of hardboard web in I-Joist construction in some parts of the world.
i would recommend that you get some facts before posting items in this manner in the future
G'day Craig. Thanks for joining the forum. Just a couple of questions: Who are you directing your comment to and you don't happen to work for a company that supplies this stuff do you?
Pull your head in Craig.Quote:
Originally Posted by silentC
We/I, am allowed to talk about these things, like it or not.
Normally ppl who come onto these forums boots first usually get a good kicking.
Al :)
There is another old and wise saying here " Only fools and idiots come kicking at everyone with their boots on their first post." So are you a fool or an idiot, can't quite work it out.Quote:
Originally Posted by Craig Kay
But if you are going against accepted practice and quote some obscure statistic it would be better if you were specific as to where, and in what manner, and how this is independantly verified rather than say in some parts of the world.
Peter.
Regardless of whether it is accepted practice overseas.
I would rather see some REAL oregon beams in place, something with some substance, not compressed cardboard.
I pity the ppl who buy these houses.
I was in one today, and the aircon man had been, he had cut out a 150mm dia hole through the the 8mm, not 6mm web, the web is all of 160mm high .
That cant be good for strength.
Al :)
I couldnt help myself.
Red launched.
Al :p
Nor is it accepted practice.Quote:
Originally Posted by ozwinner
I haven't used the hardboard one but have used the 'Silent Floor' type. Also used Oregon and Pine. My choice will invariably be the most expensive, the Silent Floor.
I can't imagine cutting out half of any joist being any good for it's strength.
whenever new products arrive in the construction industry, there is always plenty of resistance.
When I built my house a dozen years ago, i specified the new flexible water pipes - hard to find a plumber to do it, but got no end of lectures from old plumbers about "that stuff" - every house i see now, is using it. the next product was ultrafloor - same thing, use timber, use suspended slab etc etc In retrospect an enormously more suitable product for domestic flooring - quiet, heat sink, didnt move, could tile over, limited termite access.
Now living in an older place, and despairing at HW joists, and framing - all over the shop. FWIW I did however choose cfc sheeting instead of chip for my wet area reno's. I'd kill for a dead flat floor now though!
It quite often not a resistance to new technology per se but the limitations imposed by the new product.Quote:
Originally Posted by pharmaboy2
I have hardwood framing in the original construction section of my roof which has given me plenty of storage space for things I don't use often. If I look over at the new section just built with treated pine trusses, I can barely see a passge through to gain access to the electricals let alone use any space for storage.
Back before we had computer modeling, the designs of everything from cars to cathederals used a sledge hammer approach where the design was over-engineered just in case there was some unforseen fault or to provide a factor of safety. Today we know that for instance a bearing will last say 5 million revolutions - not 6 and more than 4 and therefore define the life cycle of a product - this coined the term built in obsolesence as it combine the policy of no spare or user servicable parts. Using computer modeling the design of roof trusses only just meet the standard and don't provide for any additional loads which may be applied at a later date (extensions etc). What can be seen is that while you get less material to build the house you still pay the same cost to the building company, at least intially until the market catches up with the new tech. Then you have to pay more for the older tech which is quite often slower and more labour and material intensive.
Al,
I hate to be a spelling nasty but your sig line should be spelt, N-U-F-F-Y. :p
Hey guys this is my first post, anyway, much of the strength in these beams is attained from the flanges (timber at top and bottom) thus cutting for plumbing penetrations etc is not a huge drama in most situations. You are better of cutting penetrations into these than oregon floor joists. I realise some of you guys here are from the old school and are probably the same blokes whos work i inspect that go way overboard on things that dont matter and miss the important things that do matter. A building Surveyor / inspector will only usually accept a new product unless is has the appropriate docs to back it up. I find some of your posts quite amusing, especially some of the advice given out by those who think they know it all. I gaurantee i have had more expeirience and education than most of you but still learn new things constantly and there is only so much information one can keep in their head.
Well that my 2 cents worth