Shorter Ritchie on RAACSeptember 1, 2023 Tim WorstallRagging on Ritchie39 CommentsGovernment’s crap at infrastructure. Therefore government should do all infrastructure and more! previousFrogs, eh?nextThis isn’t so 39 thoughts on “Shorter Ritchie on RAAC” Andrew C September 1, 2023 at 1:03 pm Amazingly, despite having been in use since the 1950s, the use of RAAC was because of ‘Neoliberalism’ which as we’ve been often told, was an invention of Thatcher and Reagan. I was aware that Thatcher is to blame for everything that is happening today, despite leaving office in 1990, but had no idea her influence spread back through time as well. Truly she was even more powerful than I thought. Paul, Somerset September 1, 2023 at 1:21 pm I recall PJ O’Rourke’s memoir of travels behind the Iron Curtain, where he noted the government love of concrete, despite the fact governments clearly had no idea how to mix it or use it. dearieme September 1, 2023 at 1:41 pm I saw today that the first serious report to warn government about RAAC was in 1996. If you allow a year for Sir Humphrey to read and absorb, we reach 1997, the Year of the Blair. So lots of blame can be attributed to Toni, and to Brown, and then to CallMeDave Blair-lite. Their do-nothing approach worked: all the blame will now be put on Sanook (as Geriatric Joe calls him) with a side-swipe at Fatcher. bloke in spain September 1, 2023 at 1:54 pm How old are the schools? I’ve said this before, no building is built to last much past 40 years. Particularly applies to steel reinforced concrete. It’s a short life construction method. Though cheap. Moisture gets into the concrete & rusts the steel. The rust removes the mechanical bond between the steel & the concrete. And it all starts to crumble & lose its load bearing capacity. How long this takes depends on conditions. Can be 25 years, 35, 45…. Much depends on the maintenance regime of the building. If you can keep the moisture out, it extends the life span. But it’s not infinite. Couple hundred years, the only steel reinforced concrete structures on the planet will be ruins. Unless they keep building them. This is not something that’s unknown. Everybody in the industry knows it. Goes back to the opening premise. No building is built to last much more than 40 years. Takes you past the period the commissioners are responsible for it. And no, don’t sight all those buildings have lasted hundreds of years. They’re the survivors. The flukes. Most of them fell down hundreds of years ago. john77 September 1, 2023 at 2:13 pm @ bis I’ve only twice lived in a building less than forty years old, and both are now well over 50 years old. The oldest is now over 1,000 years old (and that was *not* a church, it was originally built as a middle-class house). I am going to cite all the housing estates that were built between WW1 and WW2 and are all still in fine condition. You seem to think that Wilson’s 1960s tower blocks are the norm (some other local authority estates are nearly as bad): no, *they* are the exxception. Houses have been built with the intention that they should outlast the purchaser’s lifetime for thousands of years. Who would choose to buy one that didn’t? dearieme September 1, 2023 at 2:44 pm I knew a girl who was buying a Georgian flat in the New Town of Edinburgh. A form had to be completed for the Building Society which was a Leicester-based concern. Its age limit presumably suited Leicester. Anyway, the flat was reported as Date of Construction 1800, Age 60 years. My primary school was built ca 1820. On Sundays I used to visit my great-grandmother who lived in a house built in 1840. The rest of her street, both sides, was of similar vintage. If I walked down to the harbour I’d be walking among warehouses of about the same age which had withstood Spring Tide floods a couple of times a year all their lives. Come to think of it in Britain I’ve lived in only three 20th century buildings (other than temporarily): my childhood home, my Hall of Residence, and our present house. Bloke in Wales September 1, 2023 at 2:45 pm John, how many of those were made of steel-reinforced concrete? PF September 1, 2023 at 2:50 pm J77 I assume BiS is referring simply to reinforced concrete type structures (otherwise you are right, it wouldn’t make sense?). bloke in spain September 1, 2023 at 3:04 pm No PF. I’m talking about any structure. 99.99% of all buildings fell down. So you get left with the 0.01%. Paul, Somerset September 1, 2023 at 3:06 pm John77: There might be survivorship bias there. You only got to live in the buildings which survived over 40 years. The ones that didn’t are no longer around to be counted. Tim Worstall September 1, 2023 at 3:16 pm OK, this concrete, it’s not reinforced. That’s the whole point of it – bubbles instead, to make it lighter. As to the larger point, I think BiS estimations of old buildings fall over rate is too high. The intention – ah, well, that might be so. Build only to length of time that gets builders out of trouble. US housing is built that way, wood frame, plasterboard walls etc. But little story. Noting Brunel’s bridges around Bath, said to Dad, well, wasn’t he a great engineer. Built for 200 tonne trains, work fine for 2,000. He laughed, being an engineer, said it proved Brunel was a terrible engineer. He’d overbuilt. # I’m sure a lot of that century old brick and stone housing was meant to have fallen over by now. But they dodn;t know enough engineering to only build for 40 years. philip September 1, 2023 at 4:03 pm I grew up in a cob and stone house that was built when the first Queen Elizabeth was on the throne (or the potty, no one knew). Fortunately my dad could afford the eye watering maintainance costs (aided by it being pretty well insulated). Not HE listed so no repair subsidy and now happily the responsibility of some other mug. As an aside, anyone know about “green” concrete? this new stuff (lower CO2 emissions) is already predicted to last only 25 years or so. No doubt in 25 years we’ll be able to replace it with long life plastic from the methane farts of dead cows or something. Bongo September 1, 2023 at 4:04 pm You have to ask: “Where were the teaching unions?” Somewhat indifferent to the safety of their members perhaps. PF September 1, 2023 at 4:05 pm BiS “40 years” – rest are flukes (or similar) Doesn’t pass any smell test. “And no, don’t sight all those buildings have lasted hundreds of years. They’re the survivors. The flukes. Most of them fell down hundreds of years ago.” I’m on a road here, with circa 100 houses (leading to the sticks), every single one of them built roughly early 1920’s, about 100 years ago. Not one of them has fallen down, nor look like they’re about to any time soon (!), generally all in pretty fine fettle. By your measure – “them’s the flukes” – then, unless I’ve completely misunderstood you, that’s statistically impossible? It’s the same all over, roads with lots of old houses on them, generally in good nick. I accept that modern buildings may not be designed to last so long, but that’s slightly different from what you suggested? Antonios Michael September 1, 2023 at 4:06 pm The buildings should have been constructed using elton. He’s still standing. PF September 1, 2023 at 4:11 pm “I’m sure a lot of that century old brick and stone housing was meant to have fallen over by now. But they dodn;t know enough engineering to only build for 40 years.” Again, this fails the smell test. I accept that in the current day and age, most stuff is shite, I get it. But different attitudes in previous times, the throwaway culture didn’t exist. Repair and maintain was expected and hence “build deliberately to break soon” wasn’t the norm? Stuff that survived wasn’t “a fluke”. Someone building a house would expect their kids/grand-kids to inherit it for a start! philip September 1, 2023 at 4:38 pm Tim Your dad was wrong. Quality control barely existed in Brunel’s day, so he assumed his materials would be a bit crap. So he adopted far more extreme safety ratios than a modern engineer would require. That Victorian industry turned out quite good stuff would have given Brunel a nice surprise, and of course saves us a shedload of money. Peter MacFarlane September 1, 2023 at 4:43 pm Where I come from, if your house was built after 1700 you’re regarded as a bit of a cheapo, not quite the thing, to be slightly looked down on. The best people have crown post roofs and suchlike features. bloke in spain September 1, 2023 at 5:11 pm Reinforced Autoclaved Aerated Concrete, Tim. RAAR. A lightweight building material. There’s nothing intrinsicly wrong with for the correct applications. Lightweight so it makes the load on the rest of the structure less/cheaper. How long it lasts? This is where yer achuwal builder does the teeth sucking thing. Let water get into it, not so long. Now the coatings on yer roof keeps the water out (sucks teeth again). The design life’s maybe 15 years. Flat roofs are always a horror. Thermal expansion mostly. I wouldn’t warrant any flat roof past 25, whatever it was made of. Local authority buildings? I don’t suppose they’ve ever had any maintenance. Or they thought to do the roof re-coating. The 40 year thing? Tim, you’re the economist round here. You should be able to work this out for yourself. 40 years out, the value of the building discounts to zero. Nobody is going to spend now on what’s going to happen in 40 years. They save the money or build something bigger or whatever. Yes, you can nearly always extend the life of a building. Maintenance. Repairs. Refurbs. But economics again. You’re spending money now on something discounts away into the future. A conversation I’ve had with many customers. There’s a building going up opposite me at the moment. They’re doing the first floor piers. Site’s rebar & mesh, poured concrete. Pier cores are an armature of rebar tied into the floor, currently shuttered & being poured. (Hopefully they might vibrate it, but I doubt it. I would have for what it would have cost in labour). I should think they’ll top out at floor 6. There’s an identically structured building down near the beach. Currently propped up with Acrows in places. Concrete in the beams is separating from the reinforcing. Late 70s by the look. I would think that’ll be coming down if it’s gone that far. Likely waiting for a developer. Design life. bloke in spain September 1, 2023 at 5:14 pm Local authority economics. Never do today what you can put off until tomorrow, if there ain’t any votes or bunce in it. jgh September 1, 2023 at 5:46 pm The 40-year thing does happen, but we see the survivors, *and* the replacements, so the visible data is biased. In this country, a ruined house is too valuable as a site to leave as a pile of ruins. My great-grandma’s house was built in 1638. Let’s say 100 houses were built in that street, and 10% fell down after 40 years. Well, in 1678 the sites would be cleared and ten new houses built. Let’s say there’s 10% that were better built and lasted 100 years. Well, in 1738 those sites would be cleared and replacement houses built on them. So what we see *is* those that have survived for centuries with an admixture of recent stuff that replaced stuff that was built 80 years ago that only lasted 40 years. I’ve seen this in my lifetime. In my Granny’s 1638 block the end house fell down in the 1960s. The site was simply cleared and a replacement house built there. Coincidently, looking identical to what used to be there, so most people think it’s the same age as the rest of the block. I know that the other end of the block fell down in the 1860s because the site was cleared and a Meeting House built there. So when we see “old houses last longer” we are actually looking at long-lasting old houses and slightly less old replacements for the old crap ones. Andrew C September 1, 2023 at 5:55 pm The Pantheon is still standing. Built out of concrete around 2,000 years ago. bloke in spain September 1, 2023 at 6:04 pm Occupied? john77 September 1, 2023 at 6:07 pm @ bis and anyone who agres with him I am past normal pension age. If buildings only lasted 40 years then all the buildings I remember from my childhood (and all the ones around them) would have fallen down and been replaced… SuperMac started his ascent by increasing housebuilding to 300k pa following Attlee’s inability to build 200k (bis would have been right if he had said pre-fabs were only meant to last 40 years or less) There are over 26 million households in the UK – at 300k pa (which no Labour government ever achieved) it would take over 80 years to build the UK housing stock. Simple arithmetic tells us that most buildings last a lot longer than 40 years. The crap built by Wilson is the exception, not the rule. dearieme September 1, 2023 at 6:32 pm “Where were the teaching unions?” Their officers probably spend their time angling for safe Labour seats. I used to be on a branch committee of the Association of University Teachers. We had varying views on everything except our deep contempt for the union’s officers. (I hadn’t stood for election; I was press-ganged because they needed someone who could count.) bloke in spain September 1, 2023 at 10:03 pm John77 What is so hard to understand about design life? Although for someone of academic pretensions I maybe it is. This is the real world not books. Any building is a complex structure with all sorts of things can go wrong. The design life is when one wouldn’t expect anything to have. Past that, you’re in the hands of Lady Luck. Design life can be infinitely extended by regular maintenance & repairs where necessary. Sometimes the repairs can be a major part of the building. Often are. That’s without the major works often undertaken for re-purposing. Many old buildings have been repeatedly re-purposed. They’re like the farmer’s spade. New handles. New blades. But still the same shovel. As for the Wilsonian build. Most UK cities’ residential cores are far worse than anything built on Harold’s watch. The late Viccy & Edwardian terraces are unbelievable shite, as anyone who’s done refurb work on them knows. Jerry-built with poor materials & mostly unskilled/semi-skilled labour. You can take them apart with your bare hands. The mortar’s mostly sand. The design life was just long enough for the builders to get down the road & round the corner with their money. It’s a tragedy more weren’t bombed flat in the War. We might be stuck with them for another hundred years If their owners keep wasting their money patching them up. (Of course one can make a good living doing so) john77 September 1, 2023 at 10:43 pm @ bis There is nothing hard to understand about design life – except in your alternate universe. When someone builds a house to live in, he almost universally designs it to last the rest of his lifetime or more. When he buys a house he wants it have been designed to last him and his widow’s lifetime. Design life of a house is not how long it would take before an unpainted window frame needed repair: it is how long the *house* is expected to function adequately. Latest UK housebuilding figures are back to just over 200k pa so it would take over 100 years to replace the housing stock. A major block of council-owned flats near my sister’s house was blown down a few years ago because it was deemed impossible to bring it up to the minimum legal standard. Any Victorian houses still standing are deemed to be better than that, although some of them are now past their original design life. They have been dozens of Wilson-era tower blocks demolished: i just don’t have details on the others. philip September 2, 2023 at 12:23 am “Design life”. A quaint concept for the builders of cathedrals – who found a pile of rubble in many cases when they were supposed to last until the returning Christ – and for builders of hovels to keep out the weather, now owned by retirees and holiday makers. What a joke. bloke in spain September 2, 2023 at 12:58 am When someone builds a house to live in, he almost universally designs it to last the rest of his lifetime or more. And how long did people expect to live after building a house? About 40 years, given that you’d have to be able to afford to build one. You’ve just destroyed your own argument. One might also point out that very few people build their own houses. They are are built for them. They’re like you. They know nothing about houses but what they see. And it’s normally the builder decides the design life. It’s in the materials used & how they’re put together. My view on these local authority buildings in question is that the answer lies in the coatings on the roofs. They have a limited life & should have been scheduled for periodic replacement. The councils haven’t done that. They’ve probably waited until they’d got water ingress & then repaired. Probably after a considerable delay. At which point the damage is done. Aerated concrete soaks up water like a sponge. Then rust starts in the reinforcing steel. And that opinion’s derived from seeing how councils treat their building stock. They’re all like that. They do remedial work when someone complains. Their inspection regimes don’t exist.* The “responsible” people are an ever changing bunch of desk jockeys haven’t a clue about what they’re managing. “I would let family sit under propped-up concrete ceiling, says minister” We’ll note at this point that the schools minister is one Nick Gibb. University of Durham BA Law. Also Fellow of the Institute of Chartered Accountants. And thus one of the country’s leading lights in structural engineering. I wonder if he’s also an expert on beefburgers? *Remember the hoohaa about the flat caked in mould & the whining about the the deleterious effects on the kid’s health? Tenanted properties are supposed to get periodic inspections, should have picked that up. They’re rare if at all. Boganboy September 2, 2023 at 3:50 am BIS One imagines the bureaucrat marching into the flat and saying, ‘You’re not cleaning this place properly. You must leave the windows open to let some air in. And scrub that mould off the ceiling!! We’ll toss you out of here if you don’t get your act together. And you’ll go on the shit list, and never get another one.’ And then the screams of racism, racism, racism, racism!!!! It’s so much easier for everyone concerned to just forget about the inspections. john77 September 2, 2023 at 7:23 am @ bis Can you read “or more”? Maybe you just didn’t want to do so. Most of the improvement in “life expectancy” is due to childhood death rates plummeting. A significant proprtion of young men and women who grew up and got married in previous centuries lived for *another* sixty years, so they didn’t want a house that would be unfit to live in when they reched sixty. djc September 2, 2023 at 10:35 am BiS Design life can be infinitely extended by regular maintenance & repairs where necessary. Sometimes the repairs can be a major part of the building. Often are. That’s without the major works often undertaken for re-purposing. Many old buildings have been repeatedly re-purposed. They’re like the farmer’s spade. New handles. New blades. But still the same shovel. Exactly. Buy a house, spend at fortune doing it up, still there after the kids have flown the next, spend the early retirement money on another refurb, Another 30,40,50 years and the next generation move in, spend a fortune doing it up. bloke in spain September 2, 2023 at 11:16 am @Boganboy It’s partly that. To do the inspection they have to get access. Despite being a legal requirement actually getting it’s another matter. Tenants don’t want inspectors coming in & seeing what’s being done with the property. They may not be the registered tenants because it’s been sub-let. There’s far more people living there than the legal capacity. It’s being used as a cannabis farm/drug supermarket/clothing factory. In the particular case under discussion, my guess was impromptu restaurant/take away food service & maybe occasional guesthouse. But most of it’s the laziness & incompetence of desk jockeys in council offices. They’re the people generate the inspection orders. Or don’t. John77, I don’t think you’re bright enough to understand this. Design life is not specified by the buyer of a house but by the bloke who built it. Those modern houses you see going up everywhere. Generally trussed raftered roofs. That softwood they use is pressure treated against insect infestation & fungus. Last time I saw the data sheets on the process that’s good for 25 years. Past 25 years, you’re on your own. So the design life of the roof is 25 years. And over the lifetime of those houses increasing numbers will become prey to insect & fungus infestations. Doing major repairs on truss raftered roofs is a devil of a job. It’s the integrity of the roof makes it work. That’s why they can use much lighter timbers than traditional roofs. And less labour costs to erect. Trusses come in prefabricated in a factory. Cheaper capiche? I suppose you could treat timber for 50 years resistance. Be a lot more expensive. Don’t think anyone does. By you’re metric, of course, they should be doing traditional roofs in hardwoods which are naturally resistant & pushing the price of houses ever further out of people’s reach. There’s a village church I know of, built around 1150, the tower was falling down as they built it. The buttress props one corner is contemporary with the tower Various other parts of the church have fallen down over the years & been replaced. The roof will be, again, if their begging bowl’s successful. But you would say its design life was 900 years because, like the farmer’s shovel with it’s new handles & its new blades, it’s still the same shovel. In reality, the design life of most buildings throughout history was put it up & hope. Why the vast majority of them have since fallen down. john77 September 2, 2023 at 11:50 am @ bis You’ve done another “bait and switch” by saying the design life is not set by the buyer but by the builder when I was citing the guy who built it to live in. And I said a buyer wants it to have been designed to outlast himself and his widow – so he hires a builder who will do that. I am bright enough to do simple arithmetic. The median age of UK housing is over 50 years as the rate of housebuilding is currently less than 1% of households. PJF September 2, 2023 at 11:52 am Ah, this must be why they won’t allow fracking – all the microquakes will fell our feeble housing stock. PF September 2, 2023 at 12:28 pm The basic need to repair and maintain is true of most things (whatever the design concept). There was that interesting clip that showed what happened if humans just disappeared. Can’t remember the exact timelines now but most stuff (incl habitation etc) gets overgrown very quickly (keeping vegetation under control being a crucial element of “repair and maintain”), and the more lasting survivors would be examples like the Hoover Dam (is the concrete still setting within that, if I understood it correctly?) and similar. But, if we got zapped one day, most physical evidence of humanity would disappear within the relative blink of an eye. Chris Miller September 2, 2023 at 2:30 pm Local authority economics. Never do today what you can put off until tomorrow, if there ain’t any votes or bunce in it. A lot of it is the division between ‘capital’ and ‘maintenance’ budgets. A case from personal experience: fifty yards down my road is a natural low point (and frost pocket) – when it rains, the water from a couple of hectares of fields collects there, a few inches deep across the entire road. About 10 years ago, the council did something about it(!), they built a huge soakaway and a couple of drains. It took a gang of half a dozen, with heavy machinery, most of a week – I don’t know the cost, but it must have run into 5-figures. But since then, the road sweeper and drain clearer that travels around the area has never visited it, so (in order to save maybe £50 a few times a year) the soakaways are completely full of silt and non-functional. (They never really worked anyway – as any farmer can tell you, an inch of rain on an acre of land is a hundred tons of water, or 100m³.) jgh September 3, 2023 at 1:10 am The timber beams in my flat are wood that had already been used for more than 50 years in ships before being recycled as roof beams a couple of hundred years ago. bloke in spain September 3, 2023 at 3:44 pm And I said a buyer wants it to have been designed to outlast himself and his widow – so he hires a builder who will do that. OK. I have to hand it to John’s superior academic knowledge & concede that all buildings are designed to last to eternity. Meanwile, back in the real world: Design life- The period a building should be able to survive its designed usage utilising regular normal maintenance (ie repainting exterior woodwork, clearing gutters etc) without developing significant structural faults. Structure being the roof, walls & foundations & services entering the building. But not the contents of the building. Thus not fittings like taps, baths, electrical switches etc. Significant faults being those will endanger the continued use of the building for its purpose. The big ones amongst faults are roof defects allowing rain to get into the structure & hazard everything else. Roofs are complicated structures. I could write paragraphs about how pitched roofs transfer precipitation that’s landed on them into the gutters & down the drains. And more paragraphs on how flat roofs do it. And it’s the weak point in every building design. Second might be ventilation to prevent moisture building up in voids & ending up with moulds & rot. They can eat into brickwork as well as wood. Survival of events. Storms, blizzards & floods. Since I picked a very arbitrary 40 year design life the structure should be able to survive, undamaged a once in 30 years event but not necessarily a once in a century event. Fire events. One would expect a building to survive a contained fire in an adjoining building but not necessarily a catastrophic fire. In other words fir checking. So design life. How long structures of this design will survive without significant numbers of them developing significant structural faults. And at any one time those faults can have been discovered & repaired ( so extending the life of the structure) discovered but not repaired or not discovered but in the process of being major enough to be discovered. That can be a very long time between the fault occurring & eventual discovery & a lot of damage can occur between the two. So we have to presume what occurs in significant numbers in some can can occur in any. And 40 years is generally round about when that starts to happen. In the past 40 years UK building control has tried to design this out. How successful they’ve been is another thing. Remedying one potential problem can lead to another. Which may take a couple of decades to reveal itself. Hence John’s imaginary buyer may, in specifying the house survives longer, may end up with a house falls down quicker. So my original question for Tim was when these structures were built. My informed guesses are. The original commissions were within a timeframe & a budget. Build something as quickly as possible as cheaply as possible. Where their great-grandchildren would be educated was not a significant factor There are a lot of system builds nowadays will do this. Retail & industrial parks are full of them. Cheap lightweight structures fulfil an immediate need. But at the expense of design life. It’s not a problem. It’s not required. There are ways of extending this. Usually, again, it’s the roofs. Flat roofs always have short design lives. They’re just not a good design for a rainy climate. Any rain land lands on the roof is inclined to go down the first available hole. The coverings need regular inspections & any defects (if they can be spotted from above) rapidly repaired. I doubt if the entire roof covering had a design life past 25 years. In reality, few flat roof coverings have. Water got through the roof covering into those RAAC panels, which soaked it up like a sponge. That could have been going on for years before its capacity was exhausted & the excess started dripping through ceilings on particularly rainy days. By that time they were thoroughly, well & truly. – the technical term is f***ed. The reinforcing was corroding, the aerated concrete detaching from it & crumbling & its structural strength disappearing. In other word it’s a poor choice of initial design materials compounded by inadequate inspections & absence of proper maintenance. The could have compensated for the material deficits with the inspection & maintenance regimes & extended the structure life indefinitely. Periodic roof covering replacement would have done that & even been economically justifiable. But local authorities specialise in not doing things like that. Leave a ReplyYour email address will not be published. Required fields are marked *Name * Email * Website Comment * Save my name, email, and website in this browser for the next time I comment.