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It depends! But here is a rough outline of how we go about designing steel fire protection. The following is in the context of the self builder, not multi storey, multiple occupancy structures. Ok, the process / theory is.. roughly this. The starting point is to understand how steel behaves when it gets hot. Someone ask me / others a while back.. why does my oven not start to melt / distort when I cook a pizza hot? The above is what we call a fire curve (SCI, Steel Construction Institute data ). There are different fire curves. They vary depending on fire loading (how much and what types of stuff can contribute to a fire, how "intense and rapid" the heat delivery) but the above is one we would refer to in a typical domestic self build. You can see that up to about 350 Celsius the steel maintains much of its strength, which is why your oven does not "melt" and fall to bits. After that the steel strength starts to plummet. When we fire protect steels as @saveasteading says This is correct. All we are doing it to stop the steel from getting hot enough, then soften too much, and thus not carry the loads on it for the time required by the building regulations for example. Now we can either select a geometry of steel member and make it very heavy such that there is so much mass of steel that it does not get heated quickly enough to soften to the point of failure. In lay terms. If we had a solid round bar of steel say 150mm in diameter it has a large cross section area compared with the exposed surface. This is what we call the heated perimeter / cross section area ratio (Hp/A), the Euro codes have slightly different way of presenting but they mean the same. They are presented using the ratio Area / Volume, A/V. But if we have the same cross section area of steel and weight in an I shape (a universal beam) it has a much larger surface area and thus will heat up much more quickly and thus lose strength more quickly. Now we ain't going to be using solid 150mm diameter steels. What we could look to do is is insulate the steel. This could be by way of fire proof plasterboard or intumescent paint. But also we could build the steel into a masonry wall and maybe have only one side exposed to the fire on the inside of say a garage. Or we could have the steel built into a floor that in itself insulates some of the exposed faces of the steel. Below is a screen shot of a table that shows how we need to consider the exposed sides. They key here is that the lower the section factor the slower the steel will heat up. The section factor changes depending on how many sides of the steel are exposed. But to go back to what @Great_scot_selfbuild asked., which was how heavy does a steel need to be so it does not need fire protection? The info below is taken from Corus literature 2003 as an easy generic example. The bottom line (Hp 61m^-1) is of interest to us here in a domestic self build. Using a design temperature of 550 deg you can see that the bottom blue line hangs in there, all other things being equal for 30 min. So let go back now and find a steel section with a section factor of lower than 61 m^-1 to try and get a handle on how big a column needs to be for example. A 203 x 203 x 86kg/m is a candidate if it has three sides protection (section factor 60), but that is a heavy steel. You also need to handle this safely on site. Ok let's see how a box section compares. Ok we can get down to 60 for three sides exposed protection.. not much difference. But if we reduce the sides exposed the numbers get a lot better. I've not shown them here. That main remaining key bit is what we call the load ratio mentioned above as 0.6 ratio. When we design a beam / columns or pretty much any structural member in your house we design for the normal expected loads. The self weight, permanent loads and the imposed ( live loads, people, book shelves etc) but in a fire we recognise that the floors, roof etc are probably not going to be fully loaded with people for example during a fire, the permanent / self weight load is still there. So we can make a reduction in the load if a fire occurs. Its based on probability and the loads that could be reasonably expected in the case of a fire. We call this an accidental load case and the safety factors get reduced for example. If we designed everything for the worst case buildings would be too expensive to build! The load ratio is the load (stress generated) during a fire compared with the ultimate capacity of the member. Often we design beams to be restrained by say a timber floor.. but if this has burnt away we can't count that. To conclude: The above I hope, gives you all a bit of insight into what we need to do / think about to design steels for fire. The take away is that sometimes it works using a heavy steel to avoid the expense of fire protection. The design can become much more complex if bolted / welded connections need to be taken into account. This kind of design consideration is a bit complex if you've not done it before, it's not common bedtime reading! It can be a tricky subject once you get into detail, something that many Architect's, BC officers are also not too familiar with. But it's a fundamental part of producing a safe design. My objective in writing is to try and help BH folk gain a bit more knowledge so you can ask and phrase any questions you have to your designers from a lay person perspective. You make a good point. Yes steels expand in a fire and will change shape and distort the surrounding structure, to the point it often has to be later demolished. The objective is that the building hangs in there so it does not fall on the fire brigade, set light or fall onto a neighbouring building not least.

Where things are at... https://youtu.be/nl__O_QGIR4?si=G_CGnPuO8etvYzmV

This is standard detailing, for any spark. Was going though this today for 1ph ovens (x2), 3ph induction hob, 3ph ASHP's (x2), and 3ph immersion. Lots of very comprehensive discussion was had, and that means the CU will be sized, populated, and comply fully without any hiccups Breakers (or fuses) have always been sized historically, like 15a rewireable fuses for immersions, so this is not anything that's ever overlooked in my experience.

I just looked at that website and I think your chosen interpretation is a bit pessimistic.

I think that is exactly right. The restart limit was set to 8°C to start with, so cooling to flow temp of 15°C meant that it had to get to 23°C to restart. That was identified in the call with the energy lab tech dude. So I can now play with the restart min temp difference from target but there is clearly another register i need to tweak. Just got to find it. Im sure it’s here somewhere…..

Here is a bit about uranium reserves. About 90 years worth at current usage. So if we doubled (globally) nuclear generation, about 50 years. Would be hard to build a facility when you know it will be hard to fuel it before it's end of life. https://world-nuclear.org/information-library/nuclear-fuel-cycle/uranium-resources/supply-of-uranium

Goodness, thats a lot of dosh. Fab info though. I know what I’m like, I’ll muddle through and waste £602.57 on lecky I could have saved if only I hadn’t been too tight to spend £400 on a monitor.

Yup. It'll stick like shit to 2 blankets I've never bought marine ply as if the water is getting to the plywood, you're already wrapped in both of those blankets!

I've bought this from Wickes before I even clicked on I should have got marine ply. Wickes 6mm ply Will this stuff be ok? I'll be tiling, so priming and flexible adhesive on top of this.

Took me a while earlier:

All I see is a man up a lift.

There is no real point in continuing to discuss with you. we are at polar ends of the spectrum. You think you are right as do I. Only time will tell.

It is not that I don't like alternative forms of energy generation. It is moderation, balance and diversity that we need, not religious fervour. Energy efficient houses great, the more the better. But spending vast sums on subsidising one energy source and demonising another is foolish. It assumes we know all the answers with certainty, and we are absolutely right and certain about what we are doing. I say beware the certain evangelical man because quite likely they are a bit stupid to lack doubt and uncertainty. Yes in the long run fossil fuels will run low. But there has to be a balance. Making an energy transition is a 50-100 year journey. During that journey technology will advance in astonishing ways. Explore and advance all options. Nuclear fission is here and fusion will eventually come. That is your belief, not a known proven or unchallenged scientific fact. I am glad you care about our descendants, but there is no ''climate emergency''. Don't mistake fear and propaganda for what is really known. The IPCC have just burned the scenario all the climate emergency peddlars use as unrealistic - it aint happening - it aint necessarily so. There are many threats to humanity, a new ice age, asteroids, global warfare, planetary pollution, pocster, etc

Ffs the top floor windows are wrong as well. how can somebody have the knowledge to replace a lintel and not follow the brick bond. baffles me.

Ah. Not sure what a plumber has to do with that. In my mums cold bathroom with relatively weak shower she specifically asked for the fan to be moved further away from the shower head because she thought it promoted cold. Couldn't tell you if it made any difference (used it before and after) but I could see an argument for wanting more steam to hand around (for a short while) in a room like that. (Of course consequences are condensation everywhere but that's another matter).

What he said 👆

Its a stretch to state that these are big con! Visual and noise impacts - visual, don't agree, noise, the juries out and location can somewhat mitigate that. Interference with radar and defence operations - really? The culling of birds - presume you are in favour of the culling of cats then? That oil jobs will go - more of a pro than a con in my opinion Fire and collapses do occur - really, didn't know that, good job oil production is harmless then! Low effective efficiency given curtailment and the inability to match supply to demand - the use of battery storage seemingly will help with this. Listen, I get that you don't like alternative forms of energy generation, but given what we have endured for many, many years from high CO2 emissions, and given it is our descendants that will suffer the most, your defence of the status quo is just beyond the pale!

Shame I am work at the moment. When I studied RE we looked at all firms of electricity production. Nuclear, when generating is very low CO2 generation. The long term storage is a problem, mainly political, latest idea is to bury it in the Irish Sea mudstone. It may happen. There is a question mark over the security of uranium supplies, processing, transport and storage. Regarding the excess thermal energy heating the atmosphere, not really. But local heating is a problem, as is excess air temperature. A French reactor was on reduced power because it could not get enough cooling. All large thermal plants cab suffer from that. The main thing is to reduce the CO2e gasses and particulates. These are the main problems. CO2e gasses do not act like a blanket, depending on which model used to calculate, it really just allows more energy to be stored kinetically (temperature is the mean free path speed of molecules after all).

Heat and steam off a decent shower will negate any feeling of cold / draught etc.

And while you are doing this you could look at modifying or replacing the first floor cills. It is difficult to chase out cement mortar from soft bricks without damage. Do some research on what you want.

We should strive to be rational about radiation and nuclear power... https://www.amazon.co.uk/Radiation-Reason-Impact-Science-Culture/dp/0956275613/?_encoding=UTF8&pd_rd_w=bg1jN&content-id=amzn1.sym.5e81eabe-938d-4936-a067-ca199f0f9913&pf_rd_p=5e81eabe-938d-4936-a067-ca199f0f9913&pf_rd_r=262-7534544-0018501&pd_rd_wg=xTSmn&pd_rd_r=7fc92425-cede-45b3-9dab-8d1f26ca4128 You may enjoy listening to him... https://podcasts.ox.ac.uk/radiation-and-reason Some think we should fear cow farts, some viruses, some asteroids, some free speech. Choose your poison carefully but always be afraid.

Someone mentioned the need for fuel in case of war earlier. It's been said already, but it's an awful lot easier to bomb refineries and oil pipelines than it is to bomb solar panels and windfarms. And as an importer of fuel it's also a lot easier to blockade/disrupt shipping than it is to stop the sun/wind. See Russia

What has 4 legs and goes woof. There are rig and well fired everywhere. Kuwait had a lot.

Every windfarm is cleared (or not) by MOD. Much overstated, see any research on the topic. Not specific to wind. They are going regardless. North sea is a declining basin and fewer fields are cost competitive. Oil can be sold regardless of whether it is used in the UK - see Norway! Blade factories in Hull & IoW. Vestas Nacelle factory coming to Scotland Monopile fabrication facility on Teeside JDR Cables at Hartlepool, multiple Prysmian cable factories We probably make as much of wind farms as we do oil and gas facilities. Piper alpha?

And an Irishman won the Tour. Actually that was a year later.