saveasteading

Without referring to documents.. It takes a huge temperature rise for steel to soften and fail. If it was all exposed to fire the heat would rise more quickly than if some is protected. A skinny section of steel conducts the heat more quickly. So a typical example of partial protection is being partly enclosed by a wall or having a concrete plank floor sitting on it. The steel is not being protected in the long term. Continued heat will make it fail. But it is being designed to remain structural for a period of time. Thus we could find that an exposed light column needs lots of intumescent paint while a heavy section needs nothing or a thinner coat. I've dealt with 3 fire damaged steel buildings. An agricultural one was a write-off. One we had built a few years earlier only needed cleaning and painting. The third was within an external fire wall (steel cladding and fibreglass insulaion) .. no damage other than to the paint on cladding and column (fire officer amazed).(the fibreglass was converted back to sand). I don't know if that's a complete or logical answer, so keep asking.

This happened in my uni year one. Tiny portal frames tested to destruction, and thus stuck in my mind thereafter that a frame needs 3 'pins' to form. (You can see that in the photo... top, middle bottom have all rotated.) If it had simply been 10 minutes of a lecture it wouldn't have had the same effect. Dead load becomes dynamic load. Also that the loading of the remaining structure becomes out of balance, and in the RP example the floor collapses are accumulating to be ever increasing loads.

Not a pretty sight. And then there is getting out again. How did I know it would be CT1? Or Snibbo as it used to be called.

" it’s a steel frame building, so it would not be a total collapse. It would be more of a localised collapse. " Wishful thinking perhaps, or some words to keep the shareholders and banks happy? Steel buildings can collapse. There is an inherent ability for them to crumple and come to some sort of stability if there is a localised failure. But I don't think this was designed for back in 1960. in Europe we have to design to prevent "disproportionate collapse" ie one failed element, eg from a gas explosion, would cause only local damage. see Ronan Point 1968 That's a fire officer...

It's one of these area over perimeter things. So a chunky steel possibly needs no protection, an certainly less... I've had lots of cases, and knowing the principle can save money and also be easier to build. (To the extent of using a structurally inefficient steel because of the fire and geometry benefit... this seldom happens in a linear design process. ) It's the exposed area, so with a fire on the inner face, only that area counts, divided by the whole cross section. Thus a column in a wall is less exposed than one in an open area. The info is provided by manufacturers of protection products.

Understand or know how to use them? I was never very close but have since drifted further away. A few seem obvious statements of fact, but the others? Smoke and mirrors. But if I don't believe them to be true then the world will surely end. Anyway, numbers don't exist.

Thanks all. The feet look better on this (Howdens) than the moving one* (benchmarx) and it is much bigger. I'm just thinking... one chance / shouldn't stress or rely on the plumbing. *It slides when leant on, then the legs snap or break off the base, then the kickboards have no support. I'll add some sticky stuff and have another look at it overall.

Kitchen island going in now, using a fitter. I would like to screw the feet down, as we have one that moves if leant against. But the new one is bigger, heavier and has plumbing so probably won't move. The ufh pipes are omitted at the area. Screw into 40mm screed? Or maybe stick it down with silicon or tape?

I probably wouldn't. You are proposing to lift it 200mm above what you previously thought. But is there anything on the drawings that could be used as a height reference? It sounds as if you can only use a scale rule. Is the height going to be referenced to adjacent buildings, the original (gone) or ground level? You will probably raise ground level to match the higher building. If height was considered sensitive then there would be a condition. Can you flatten the drains by using bigger pipes, or finding a shorter route?

Fortunately for me, the pure maths can be tertiary or whatever comes after that. Of course I did maths up into uni but there is a big gap between what I could ever fully comprehend and what dedicated mathematicians do. Ie I could repeat a formula with new input but not create that formula. Another difference seems to me to be a grasp of what is happening by way of load transfer in real life, which some of the best theoreticians can't. There is room for all, and it is important to have both, but numeracy has to be on a high level ( people who can't do it think it's a trick / smoke and mirrors). Back to the building failure. It will all have been manufactured offsite. Sometimes a building intended to be raised later might have columns cantilevering above the roof. Another cynical thought is corruption. I've seen a few reports over the years of criminals in develoment who threaten supervisors. Big time threats. We will probably never see the detail as this drops out of UK news interest.

they become brick slips or hardcore easily. I agree it is wasteful.

Been reading without comment as I don't know aerogel. But my inclination is to keep it simple and ensure a good, solid and permanent connection. What area of steel are we talking about, relative to the wall area? i.e. is it the biggest deal to get maximum insulation? And what depth is available? There are several makes, too and its available at my local BM (and yours) , Topps and at Wickes, so about £30/m2 and no transport cost. Depending on detail and access, I'd probably stuff the void of the steel to stop that cavity being cold, and also reducing overall heat loss.

It looks to me as if the column is not continuous but has a butt joint at mid height, then spliced ( very badly) and all concealed by sprayed concrete or similar. As such buildings are normally designed in great detail, and fabricated offsite, to slot together I'm guessing there has been damage and a bodged repair.

These temporary props will be supported on a beam, as the one above, which is supported by a column..... as the failed one. Walk gently. And these are empty spaces with previous internal loads removed.

It's a column but supposedly experienced people are calling it a beam. Is that a US thing?