Why Do Architects Insist on Using Flat Roofs? 

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Prof Dungeon Master himself! Deathbringer must not be far behind...

Sometimes the algorithm works, Amazing!

Same here! Thanks youtube!

DEATHBRINGER HAS GRACED US WITH HIS PRESENCE

They're making a penthouse ball pit!

Forgot about that.. however I would just climb up and get it...so those with such abilities will thrive whiles the weak shall perish

Evolution at work Bois ...start doing pull-ups again and working out

How could we evolve if regulation is all we know - itachi uchiha

Are you the Janitor?

We use them in Canada when needed. It’s a necessary evil due to the need of room for things like air conditioners , complex ventilation for large kitchens , solar ect ect. But they are known to leak. It’s all about getting a warranty from whatever roofing company installed your flat

And most importantly - they did not have snow.

@@JohanDanielsson8802 except for that one time

​@@BigpapamoneymanMVPtypebeat what's a solar ect ect?

@@unvergebeneid “ect” is short form for “etcetera” which is a word used specifically for the end of lists, that are to long and extra detail is not necessary. For example I could of named patio, rooftop green house, roof top pool, bat signal

In architecture school I was told that slopped roof on high building is dangerous, especially in climate that I live in

The solution is generally a steeper roof, or designing for the flow of snow to target someone you don’t like

When I framed houses, decking the roof was the part I dreaded the most. I live in FL, so most were only a 4 - pitch. But being a small guy if a gust of wind came, I would using just have to let it go. Otherwise we'd both end up on the ground. Thats why if I could I'd be the cut man.

Built a house with my buddy over the last year. Shed/flat roof would have made it sooooooooooooo much easier to do, but it snows here, and the HOA where he lives has a roof pitch minimum lol. I'd do shed/flat roof on any house I build and want to live in myself, I love the more Modern/MCM look anyhow

@@ChuckD99 Yeah it kills your back. Just nailing it off and put unlay is bad enough. I wouldn't be a roofer. Though I've seen some roofers with basically couch cushions for kneepads. That way they didn't kill their back bending over constantly.

@@ChuckD99 Was it a hip or gable roof? Just getting the trusses set properly on a hip roof can drive you crazy.

@@fukkitful gable roof. I don't think a shed roof would work well for his house but I'd just design or get plans for a shed roof if/when I build haha

It's people going for the cheapest quote. Getting poor quality people. That simple don't have the skills or knowledge. Even the Germans use flat roofs. I've worked in both countries.

@@BillyMustang101 My late parents house had an attached garage with a flat roof. That flat roof had to be renewed four times over the fifty years they lived there.

I did work on one of those extensions. I tarred the roof, green as all hell I was mind you. It took attention to detail more than anything, our friend and neighbor who is an actual handyman blew it. All I did was make sure the tar made logical connections with the flashing, and press on the roof to find leaks. P.S. roof tar doesn't like being 10 layers thick. It contracts/expands during thermal cycles, if it's thicker it splits more readily.

The town-home I used to live in had a section of the roof that was flat that held the heater/air conditioner. They leaked all the time and it was very expensive to lift up the air conditioner unit to fix the roof underneath it. I will never buy a home with a flat roof again.

except for reed tatched roofs.

So much for education these days.

sycophant

@@ManInTheBigHat what are you really trying to say? 🤡

Lol. Did the roofs collapse from all the 💩?

Class at a University?

To which industry did you move?

@@farukbozkurt7730 I’m just a bartender. About as useless of a human possible.

​@Robert Caswell I don't think that's a useless job. As a bartender you provide people with a valuable service. Bars are important places to socialize and hang out with friends. You are certainly adding a lot more value to the world than a stockbroker. You should be proud of what you do. No bartenders = no bars.

Hoping that the flame ignited continues! Here’s a tip, bartender or architect, let excellence be your guide. It will certainly take you places. 🙏🏿

Retired architect here. The majority of our firm's practice was in South Florida in what is described as a salty, semi-tropical environment with a high rainfall and a high humidity. We selected whatever was appropriate to the project whether it was a "flat" (correctly called a "low-slope") or "pitched" roof. Roofing failures are primarily due to inappropriate materials selection, incorrect design details, and/or poor installation/workmanship. Always reference the NRCA (National Roofing Contractors Association) and SMACNA (Sheet Metal) manuals whenever one is selecting materials, designing details, or inspecting an installation. Reminder: Nothing is "water-proof." Some things can be made "water-resistant" ... for a time.

I haved lived in a 100+ year-old flat-roofed house fir 20 years in London Ontario, formerly lots of snow. Interestingly, the style is squarish, neoclassical, central floor plan. Old neighbours in the know claim the original owner-builders could not afford a proper (probably mansard) roof, so made it flat. Ten yrs ago had the 2nd-floor ceiling open, and saw it had a slope--16" at centres, down to edges. Had roof recently replaced--also flat. One corner wood rotten, and we were getting ice buildup on that corner. Not cheap. The previous roof might have been 30 to 40 years old--don't know. Note that when I look at houses I immediately look at how much space is wasted, usually by a pitched roof. Arianne

You speak of poorly designed flat roofs. I'm a flat roofer, we never rely on caulking for water integrity. Caulking is only used to help with water flashing, but is never considered a true seal. Ironically many steep roof systems do rely on caulking as a sealant.

​@@awitheford If you think space is wasted by a pitched roof, it is due to imagination, not the roof style. A lot of houses use the space of a pitched roof for things like storage or extra room. Open your mind to the possibilities :) And I will add this world would be a boring place if we only worried about "practical" things and didnt also think about the look. pitched roofs just look better generally, moreso outside of the inner city of course, where real estate is more valuable, spare land non-existent and you have to focus aesthetics elsewhere because you have to utilize every available space for practical things.

I’ve spent many summers and winters caking various forms of goo and patches to the flat roof of the shop I worked at (Also in the PNW). Always standing water, always leaks, which are impossible to track down. Miserable design. An architect or builder is clueless in regards to the damage these roofs cause to a wood framed structure after 40+ years.

Location and weather make all the difference. Sloped roofs will always be better in wetter and colder environments. But if you live in a fairly dry and hot place, you want the least amount of surface exposed to the elements. That is why old middle Eastern buildings were built flat and very near each other, while in Scandinavia very angular roofs were the norm. Form does follows function I guess

I suppose they could start including a means of heating those flat roofs, where snow loads crushing said roofs is an issue. Something they turn on only when snowfall is over X amount, say. Can't be that new of a thought; my aunt mentioned having something like that added to her roof, to speed snow shedding.

@@cchastant8251 Yea that does exist but it's quite expensive for commercial buildings. If you want to heat bathroom tile you run the heating wires just below the tiles. But an exterior roof has many layers of materials, including insulating layers, before you can place heating wires. So to heat the roof you pretty much have to warm the entire structure to the point it will melt the snow on top of it. It's kind of an insane thing to do IMO, but it is done sometimes. The far better solution is to just build a roof strong enough to carry a snow load far beyond what your climate will see, and angle is slightly so it drains when it seasonally melts. For your aunts case, they might be lining a heating wire around the base of the overhang so icicles aren't forming and snow doesn't have a spot to begin to pile up from, but there are heated gabled roofs too it's just again not super common.

I live in an old converted barn with they stereotypical multi angled sloped rood, and we simply do not have gutters🤷‍♀️

@@cchastant8251 Then you need to solve the problem with iceformation too (at the areas not heated) as you need to drain the melting snow. Only one powerout during midwinter could lead to disaster as the drains would freeze. Solution would be to keep the heating up constantly (for the whole system), but that would be extremely unefficient.

You got ripped off twice by a bad roofer.

That's called an icicle. They form if there is an overhang, and they kill people anyway.

But ice only builds up/stays in place of water is allowed to stay in place for a while, on a sloped roof this is not the case as the water naturally flows down. (Of course you will have some minor build up but it really isn‘t a big problem)

@@PhilfreezeCH I dont think you live in an area with snow. Wet snow sticks to sloped roofs and melts and refreezes over time forming very hard ice

@@PhilfreezeCH Maybe live somewhere that snows first before commenting🤦‍♂️

If there is an overhang, it won’t matter what shape the roof is, there‘ll be a chance for icicles.

I started typing...then saw your post that basically said it all. 👍

Flat roofs are a result of changing things that dont need to be changed via, "change for the sake of change "

Thing is it could have an incline and have a lip, my home & garage looks like they have flat roofs- it has a lip around knee high I just chill on the garage sometimes

*slope

@@VincentGonzalezVeg A lip? I'm guessing your talking about a knee wall lol. Yeah every roof has a pitch to it even if its just a 1. Porches will too if built right but they only need to drop a few inch. That way water will run off and not sit. And you need an extra layer of waterproofing, something thats selfsealing like ice & water shield not just tar paper or tyvek. A house I worked on had a few years ago had a rooftop deck . It was 4 stories, close to the beach so the view was nice looking south. Only problem was it was on a tiny lot. squeezed between 2 3 story houses. So if you looked east or west you would be looking into your neighbors windows.

20 year water accumulation? You do know water evaporates right?

@@KeyserSoze23 water also soaks into, corrodes, or weakens just about every material over time.

@@KeyserSoze23 bro 💀

That is due to power construction not the design

@@KeyserSoze23 and it come again every year

Thanks for your input and that's good to know!

Actually they are determined by the cost of the ground they are constructed upon and the "need" to squeeze as much as possiblle out of the space, regardless of the TCO, or the after effect when the owner of the building moves on.

@@dangraff8467 Thats blatantly not the intention of the statement he made. He is obviously saying a more complex building, which most "good" architecture would tend to fall under, has more potential for failure points, thus more potential for leaks.

​@@dangraff8467 If you build a cube out of block with a single sloped section of roof, it has a lot less potential points to fail and let water in than if you build something like Falling Water or the Notre Dame. Just like owning a sportscar, owning a complex piece of architecture has pros and cons, his statement is in support of someone choosing to prefer something more practical, said in a playful way. He obviously does not judge buildings' architectural importance on the level of water which makes its way inside, and I don't understand why you'd choose to ignore the metaphor other than it being a poor attempt at being a troll.

@@dangraff8467 It'd be condescending of me to belittle the well-intentioned professional who is creating a freely accessible educational video on a topic in a field which I do not work in for using a metaphor which I choose not to grasp, but I wasn't the one who did that.

@@dangraff8467 prior to starting an architecture centric channel... *he had no idea that flat roofs were so divisive*, which I think is fairly understandable because of their widespread use. No disrespect to you, its plenty fair to argue against the use of flat roofs in certain applications and climates, *all* I was saying is that claiming he thinks leaks are good is a silly jump. The fact that he dedicated a whole video to diving into the pros and cons of both flat and traditional roofing would suggest he does genuinely care about those who are inhabiting these buildings. I am *literally* a professional builder and developer who has a very heavy hand in the design process of everything I create, there truly is almost no one size fits all solution to *any* issue in the building world, unfortunately everything is weighing the pros & cons and that is even more obvious when designing complex structures. Any architectural choice on a building can have widespread effects which would have been very hard to predict... plus, on very expansive projects things tend to fall through the cracks much more easily. A really great real world illustration of the mistakes made on the first go around are actually in a different sector - cruise ships - The first ship in a brand new "class" of cruise ships will always end up having its design tweaked and tweaked for each additional "sister-ship" built, effectively making the first ship a beta test for the following ones in the class. However, we tend to less frequently build identical structures (baring large corporations, there are actually some incredible examples with nearly identical skyscrapers being built in opposite corners of the world, or things like fast food restaurants which are very copy & paste) in the building world, and instead we have to just try to apply concepts learned to the next one. 🤷‍♂ I appreciate our discussion - have you had bad experiences with flat roofs?

@@TryAgainPlease stop arguing with this guy, he's clearly not being reasonable. It's clear to anyone that watched that the creator of the video doesn't "think leaks are good architecture" so I have no clue why he's being so obtuse

Very true, when I think of flat roof homes I think of contemporary American homes that maximize floor space and ease of construction over form or aesthetic

@@Foamypeon I agree. However, I also believe that maximizing floorspace and easing construction in and of themselves are underused formal generators, if done sensitively and strategically rather than it being an unaudited result of vague drawings. For example Sizas Bouça housing, or a lot of Bast projects.

@@Foamypeon I think of the roof of a WallMart

Well said

Indeed I think most people have a very confused sense of what is truly "soulless" and would probably sooner live in Disneyland than in an artist colony.

Brasil have a warm climate, which mean that they do not have to worry about snow.

​@@JohanDanielsson8802just massive rainfall of up to 600mm/month during rain season

@@thisstuffisdumb water can move downhill wheras snow just sits

Flat roofs are moronic in the weather conditions of brazil, it will only add to more issues for the poor who cannot have a home that is resistant to damage. What you want is titled sloped roofs, people can coalesce in balconies, courtyards, or in the streets.

If a roof needs maintenance every three months, I consider that bad design.

@@bgeyssens i call it “maintenance” but it’s really making sure the drains aren’t clogged, scuppers are clear, etc….

@@roofingtips Do you make money "maintaining" those flat roofs?

@@DarkMoonDroid I have a few clients that hire me to maintain their flat roofs, but we mostly specialize in shingled roofs.

Here is Japan it's Sunshine Laws, which generalizes height limits (horizontal lines) to sloped lines. Probably in this case, the shape of the roof doesn't matter much.

@@davidhawley1132 What do you mean? can you explain a little bit more?

My city’s District Plan building regs allow for pitched roofs of specified max slopes to extend above the height limit envelope. They recognise sunlight planes are angled.

So you're saying we should end single family zoning.

Absolutely true. I've designed many buildings where the height limitation came into play. Not for the reasons most people think about though. The RTU (rooftop units) aka air conditioning condensers in any of the jurisdictions I've worked in fall under the purveyance of the height limitations. The parapets and screening to hide the RUTs however are. Flat roofs allow us to get the client the maximum bang the for the buck while keeping the constructability feasible and costs in check. I myself prefer to use single slope roofs with variable truss heights to provide a 3 slope roof. This allows for more drainage locations. Extra crickets with variable pitches as well (to allow for shorter runs to the point) increase the potential drainage locations. As one of the top 1% revit gurus in the US (ego stroking yes but I made sure to learn from the best aka Aaron Maller), I've also created the families to better enable both the project manager and the mechanical engineer to calculate and accommodate roof drainage regulations in the jurisdiction we're working in.

Shhhh

From my experience maintaining a flat roof waterproof costs practically nothing. I haven't spent a penny on maintenance on it in 20 years and it has never leaked. I think all these problems being described here about leaks and collapses and what not are just a result of faulty design by the architect responsible, poor choice of materials and poor workmanship. There really is no reason why a properly built flat roof should leak or collapse unless a plane falls on it or something extreme of that sort.

@@listerdave1240 there is also literally no reason to build a flat roof if you don't want a balcony on it. So if you don't want a balcony getting a flat roof is just plain stupid because to repair is (if something breaks" is way harder then an actual normal roof.

@@captainbube1217 The point am trying to make is whether or not you choose a flat or gabled roof should have nothing to do with whether it leaks, or how much maintenance it needs or whether it will collapse with snow. In those respects there is no difference between a flat and a gabled roof as long as they are both built properly. If you want a gabled roof because it looks nice and traditional then that is fine, and that is just about the only good reason there is for a gabled roof. If you want a flat roof because it is more practical that is also fine. What I don't agree is what you say that repairing a flat roof is way harder than an 'actual normal roof'. First of all for me an 'actual normal roof' is a flat one, whereas a gabled roof is one that has better aesthetics. I'm not quite sure what repairs you are referring to that a flat roof might need. Unless an airplane falls onto my flat roof I don't see it ever needing any repair. It's been there twenty years and it is just the same as it was when it was built. Even if it were to collapse due to some catastrophe, building it anew is neither difficult nor expensive. I don't know that much about gabled roofs but I don't quite understand how any roof can be easier to build than a simple flat concrete roof.

@@listerdave1240 there is a massive difference when it comes to snow and ash. Flat roofs can't shed those things at all. And I do mean at all, it just builds up until it stops snowing or ashfall stops. Gabled roofs don't have this problem because the snow or ash just... Fall off.

@@captainbube1217 This video gives plenty of reasons why buildings have flat roofs.

Ah, I often wondered that, thank you. I think Montreal, Quebec would be a good example as well as the majority of buildings and homes have flat roofs and that's a likely a major factor!

I've seen some incredible snowslides off the roof of my town's sports arena.

In snowy countries there are often horizontal rods or a series of notches attached to gabled roofs to keep the accumulated snow from sliding off. This is common in e.g. the Alps and the Carpathian Mountains. I’m some other cold European countries there is an architectural tradition of very tall, steep gabled roofs on which the snow doesn’t build up.

@@timpauwels3734 Yeah! Here in Canada asphalt shingled roofs tend to hold the snow fairly well in most cases, but on metal roofs you see those little stoppers or rods almost always. It's neat to see all the different methods to tackle the same problem!

Excellent point. I have one of these new popular metal roofs with a significant pitch, and when the snow comes off, it comes in one huge sheet. Imagine a 10" snowfall sliding off at once--it's enough to bury a small dog that happens to be relieving themselves at the moment.

@UnjustifiedRecs All roofs will eventually leak. At least where I grew up, the flat roof on the garage leaked a decade after the sloped roof.

Yep, even when they're new.

Your grandfather likely worked with materials/types way shittier than modern options.

As a matter of fact he also could repair them much faster and easier than a slanted roof. It was also of course much cheaper than a slanted roof.

Flat roofs, at least modern ones that are mopped and have 3 layers, should be pretty leak free for at least 10 years. If you have a leak right after installation then your roofer did not install it properly. I've literally reroofed flat roofs myself and currently do permitting for all kinds of roofs in Miami. The biggest issue with leaking for flats is ponding. Water accumulating on any surface without proper drainage will always cause big issues. If there's a chance of poding then your roofer should have already considered that and suggested to install a tapered roof system using some kind of insulation board.

Hip roofs work great in high wind areas and use much less material. There’s that.

Nothing wrong with a 4 sided gable. The multiple ridge lines however are indeed fake and silly.

Ive literally never seen a 4 sided gable. I'm sure it exists but that sounds like roofing hell. You might be thinking of a hipped roof. A hipped roof is a pitched roof without gables. Just like a gabled roof is a pitched roof without hips. Really kind of dissapointing that an architect spent a whole video calling pitched roofs gabled roofs. All gables are pitched, not all pitched roofs have gables.

McMansion=I live in a high housing cost state and am jealous of new large houses.

this is a condition of switching from traditional design to CAD. in the past: when you set out to design a building you started with the roof plan, from there establishing the building line. now we start with floorplan based design and the building line becomes a mess. then the roofs are usually just generated based on a supplied pitch to the software. nobody ever contemplates it beyond that in the design phase.

If the roof was not designed to be green roof, that can be dangerous to make it a fully green one.

@@yamatohime2035 Yes, anyone wanting to do that should always check with a structural engineer first.

But you have to distinguish between real green roofs with enough soil for bigger plants and those with just a few cm/inch of soil. The latter one has a small water holding capacity and only small plants on some plases so that patches in betwean stay empty. Duet to the amount of dark soil, these rofs can rech eaven higher temperatures than thas with gust gravel or membrans.

@@doublef3278 Then maybe the architect used the wrong plants. There is a difference between intensive green roofs (>10cm of substrate) and extensive green roofs (10 cm is 0.3, so 70% of a 5-yearly rain is retained, for the

@@JainZar1 Interesding. So what you are saying is that even with extensive green roofs (wasn't sure if extensive/intensive is used in englisch too) there's enough water so there are no spots that are not covered in plants if you chose the right ones? Is that fore almost flat roofs onely or is the differens in lost water by a higher angel negligible?

Exactly ... find me a 10 or 20 year old flat roof that doesn't look like a jackson pollock painting made with polyurethane sealant (as the owner has played "whack-a-mole" with the leaks over the years) and I'll present you with a unicorn horn, or some hen's teeth. They're about as common!

@@danielscott4514 My roof is about twenty years old and it looks exactly the same as it looked the day after it was completed. I have never done any maintenance on it and it has never leaked. I have seen many roofs that are as you described but that is just because they were built by someone who either doesn't know how to build a roof or just doesn't care. It is not even difficult to do it properly, one just needs to not be extremely incompetent or careless.

@@listerdave1240 You should probably buy a lottery ticket - you're clearly a lucky man ;) ... you're right of course - it *is* possible to build a flat roof well, it's just a lot harder to get right than one with a slope. Seems there are way too many cowboys and smeg-heads in the building game though. It's possibly better in other countries, but even some of Australia's biggest construction companies have a history of cutting corners - and all too often those corners are cut in "out of sight" areas like waterproofing. I remember an expose on Meriton about 15 years ago (a large builder of multi-level apartment buildings who, sadly, are *still* in business) where building inspectors were brought in to a highrise plagued with issues and when they broke into the walls between apartments (which are meant to be fireproof) they found the gaps around pipes penetrating some of those walls had been "sealed" with lumps of wadded-up newspaper ... yup, that's to code! Needless to say, far too many highrise buildings in Sydney have issues with water ingress - waterproofing is a favourite area to be slap-dash!

@@danielscott4514 It's not really hard at all, one just needs to have the will to do it right. I actually find it difficult to understand how a gabled roof is simpler - it seems to defy logic that it would be simpler - I mean what is simpler than a flat slab of concrete ? Probably the issue is that because it is so simple many incompetent people get to make them because they can while gabled roofs, being much more complex can only be built by competent people. I think if the same people that built the bad flat roofs were asked to build a gabled roof they wouldn't even manage to complete it without it collapsing, let alone make it weather proof.

​@@listerdave1240 A pitched roof is a lot easier to get right because typically the roof cladding materials used for them don't require sealing. They don't require special sealants because they're not designed to have water standing on them, but to let water run off quickly enough that it won't find its way into the building (typically they rely only on overlaps of the roofing material and the speed of water running away from the joints to prevent water getting in). It's all quite "foolproof" in the sense that it doesn't rely on a whole bunch of material engineering and fussy drainage to make it work. In the case of a pitched roof that slopes toward gutters that are out over the edge of the building, even if your gutters are completely blocked up, or have been blown off entirely, water is not going to get into the building as a result. Waterproofing (whether you're building a flat roof, or a swimming pool, or an infill slab - which is a building partly underground) is actually quite tricky and needs meticulous attention to get right. Even good builders can come unstuck with these challenges - and cowboys can make a real pig's ear out of it. For a lot of buildings, a concrete slab overhead is massive overkill for a roof. Concrete is expensive and difficult to cast in-situ up at height (sure, it's done in big commercial and residential buildings, but it's not cheap - you will rarely find concrete as a roofing material on warehouses or residential homes or even small apartment buildings - e.g. up to 10 apartments). Finally (and most importantly), concrete is *not* waterproof: it's porous! Without additional waterproofing materials, water *will* get in. It will also seep in at every place where separately cast sections of concrete join - so those need sealing too. It's a lot harder than you might think to make a "simple concrete slab" over your head waterproof. The problems are only compounded when drainage fails (as it so often does) and water is left to sit around on the concrete for days (or weeks if there are frequent showers and not enough sun in between to cook the water off). If you ever stand around on a rooftop terrace that's covered in ceramic tiles, bear in mind that someone has had to carefully paint, or lay some kind of waterproof membrane between the concrete subfloor and the tile adhesive and grout. You might be surprised what an absolute torrent of water can find it's way through tile grout and down cracks in concrete to come pouring out below. Since I was having a moan about Meriton before - here's an article showing how bad it can get: one apartment owner had to build a little dam in his living room because so much water comes in whenever it rains: www.abc.net.au/news/2017-03-31/leaking-buildings-mould-court-battles-dark-side-apartment-boom/8403744 That's a 2007 concrete apartment complex with a flat roof made of concrete. It's address is: 33 Hill Rd, Wentworth Point NSW Australia - the building's name is Palermo. If you're poking around in google maps, note that both large industrial buildings near it have gable roofs made of sheetmetal: cheaper, easier to construct, more reliable, less maintenance obligations. The framing for industrial buildings like that is very simple too (as a rule they don't use trusses, but just rafters and purlins, with columns every so often to support the rafters).

Surely tops of where the trees will likely grow to.

Better yet, don't build flat roofs ever, or cities either, personally don't use any concrete/steel building, at all, 2 story buildings is as far as I'm concerned the tallest any building should be. And if you need to build a factory, well, build it somewhere else, how about on the moon, so that I won't have to see it. Man am I glad to be living in the countryside, because at least I get to see meadows and actual houses, and not ugly concrete monsters, void of life.

Worth a try. Might help with sales.

What's the R value like on your scalp? Is it still IEC compliant?

Most importantly, can it qualify for insurance?

Shed top is the way to go.

How about a hip top for a hipster?

Thanks, this was really informative!

Wait, do you have sketches?

You just defeated your argument about how sloped roofs waste space. There is little to no use for the middle of the roof. So a balcony is just fine. Many houses have balconies so they get the best of both worlds. Also, if you plan right, many peoples roofs double as storage space or a spare room. You need to think outside of the box, or into the box, since you missed so much that goes into non-flat roofs. And in America, we have plenty of space to relax in our backyard where it would be cooler than on the roof, or we can have gatherings there. In cities you cant do that, hence the flat roof practicality.

@@waltermh111 what a pompous response

@@tristennew7969 whatever you infer of the attitude, I made valid points and that's the best you got? Your comment is a waste of space lol

@@waltermh111 The issue is that you didn't make a valid point. You just very confidently stated utter bullshit, like you provide no argument for why you can't use the middle of a roof it's just a completely nonsensical point that you pretend is coherrent.

I don't see how i was defeating my point. Maybe i did not articulate it in a clear manner. What i meant to say is that roofs in Barcelona are living spaces with diverse uses that i don't usually see in other places. Also the space used was way more accomodating than a common balcony. I'd choose that roof over a tiny balcony every time.

Until someone develops a single-piece flat roof with no joints and an infallible drainage system then I don't think you'll ever find a flat roof design that rates well for "trade skill set (ease of installation)" or "low maintenance". A flat roof should be a consideration of last-resort when some other need (rooftop space, maximum floor area under the roof for a given height, etc) trumps cost and reliability.

Lived in one when young, they tend to leak more than slanted roof. Just NO.

@@bennym1956 Same here, hell of a lot more maintenance and problems. My father built the home (one of many thousands) and was an architect. He never built a flat roof again on a house for himself, lol.

There's no problem. You can put a draining flat structure on top of an only almost flat roof. Just like new York's fire escapes or all kinds of metal stairs. Should be cheap enough .

In Maine we cover it and call it an attic

I live in a flat roofed house and it is not good.

Finally someone said it 😂

I’ve never understood why gutters have not been of greater assistance in redirecting rain/snowfall to the ground. Why can’t have we have the LEED garden maybe with a clear, see-through angled roof where downpour travels down the gutters?? Or travels to a tiny roof covered drain?

are you talking about the weak housing designs? redesign it to be load bearing and water proofed.

Wet dirt is not an effective thermal insulation.

This retired architect/structural engineer always had a lot of skepticism of the whole LEED deal. I never got LEED certified nor did I want to. The concept of garden roofs has more negative than positive going for it. Anyone want to guess what saturated soil weighs? Try almost as much as wet concrete. That means that the roof structure will be heavier than the floor structure. Close to double the cost of the typical floor. Columns and footings will also be affected. I've seen conceptual drawings all the time of mature trees in huge pots on flat roofs. Does anyone want to hazard a guess as to what that weighs?

yeah man, tall rooms with room to room ventilation needs to come back IMO

As opposed to falling from the sky? I’m kind of confused what the issue would be

@@Jacobscott272 falling ice can kill someone if a large sheet falls from significant distance. Snow can build up and drop in a heavy sheet once it starts to melt.

@@valerimacdonald5146 Ahh i missed the snow and ice part and only read rain. Whoops.

To add to what you said I think that a lot of issues come from the details so an novice or junior architect might not have the experience to see all the areas that might pose problems. The aesthetic of a flat roof is really appealing but also takes some experience to get it right.

Are you suggesting no meritocracy exists, and society must be victim to every architecture student for some reason? I'm pretty sure that's not how the world actually works.

I would argue that it is actually more difficult to design a flat roof properly. As mentioned in the video, the roof itself should never be perfectly flat. However, the structure on which a "flat" roof is built usually consists of horizontal beams. The decking needs to be sloped slightly to get water to move towards drains. I am not an architect, but can imagine that it would be a challenge to spec out the correct materials and techniques to ensure proper drainage. A pitched roof, on the other hand, consists of flat sheeting (steel or plywood) fastened to a truss structure with a pre-defined slope. It is pretty intuitive how it should go together, once the truss detail is established.

@@martinliehs2513 It also needs to consider which direction the water should drain to prevent water freezing.

@@jeremyO9F911O2 nowadays, it really is with the power of peer review, we have made experts as informed as students.

Youre points are mostly correct, a welded plastic roof like TPO will perform better and better on a cost basis. He should do a whole vid on how much TPO has changed the game.

the gable roof is like a half extra floor, just add an extra floor with the chimney, something similar happens with some middle east buildings

Thank you very much! I love your channel as well!

I agree, love both of your channels! ; )

@@stewarthicks one problem with the flat roof is the missing of the overhang. The overhang takes a lot of stress and weathering away from the facade.

@@stewarthicks The attic not usable is an North American problem starting in the 1880`s. Before that, Attics where always usable like still today, all over the world.

I disagree. I think there are other virtues of a pitched roof which were not discussed, and other drawbacks to a flat roof which were skipped over. I didn't learn anything new here, but it did have the feel of some kind of agenda. I suppose a flat roof makes sense on a skyscraper since you can park all the ugly mechanical equipment up there and hide it with a parapet. However this skips past the fact that skyscrapers are generally a pretty shitty building typology, representing a 'vertical cul-de-sac' in the heart of a city and almost precluding the ability to build a walkable/carless urban setting. But don't believe me - check Leon Krier if you want some actually useful and well considered design advice.

As someone who lives in the netherlands with a flat roof, (which is decently uncommon) i have had 0 issues with my roof, no leaks and love the extra space it provides.

Couldn't the parapet and water freezing issue be addressed by draining water to the center where it is guaranteed to have some insulation year-round? (Edit: my bad, by insulation I meant insolation, "lit by the sun")

@@alessandropinto5204 All problems can be fixed with redesigns.

@@alessandropinto5204 then you have the issue of the pipe getting clogged and being uncleanable

@@vyor8837 I misspelled, where it is written "insulation" please read "insolation". Anyway, isn't unclogging a drain just a matter of sticking one of those flexible coils of wire that you can spin into the drain pipes? At least it's how we do it around here.

Little rain and zero snow. Flat roofs make sense in hot and dry climates, and nowhere else. I work in a flat-roofed building in Sweden. Every time it rains, the roof leaks in multiple places. We've been told that they can't fix it because they can't find exactly where the water's coming in. You don't get that problem in a house with a pitched roof and an attic. As for large buildings requiring giant roof pitches, well, just stagger the living spaces on the highest few levels, so you get a smaller and smaller footprint as you move up. Then just wrap the roof around the top few floors. I'm convinced the main reason for flat roofs in colder, wetter climates is cost.

There is a reason why homes don't use dome roofs. The largely illiterate workforce that builders employ don't have the education or training to allow them to understand how to build such a roof. It matters not if it's residential or commercial construction. The workforce is often poorly educated and functionally illiterate. This has no bearing on location anywhere in the world. It is universal. We design for constructability and costs in mind. Not wild fancies

In over 15 years of flat roof installing I can count on one hand the number of flat roofs I've seen with gutters. And drains are super easy to clear, way way easier than gutters.

@@austenhead5303 I'm a flat roofer, if your building is constantly leaking that means it needs a new roof and the owner is a cheapskate. Modern flat roofs do not have standing water, we use very basic concepts to eliminate low spots other than where drainage is located. But again the problem is cheapskates not willing to pay.

@@Daves_Not_Here_Man_76 well David I'm a flat roofer and while I don't know your exact literacy abilities, my own are are about as high as you can get without being a professor. I'll admit I'm more of an abnormality in my profession but a person like me goes a long way. The funny thing is that people who look down on tradesmen have only themselves to blame. Stop rewarding smart people for getting meaningless degrees for pointless jobs. In general tradesmen perform far more beneficial tasks for greater society with every hour they work no matter how illiterate they are. Also domes are stupid, they actually aren't that hard to build, especially in this era of prefab assemblies. They just aren't that great, and nobody wants them.

the problem is cost. a usable flat roof is not build the same as just a flat roof

@@Asbjoern i can imagine; it would be interesting to know what’s an average difference in cost, and which country/areas developed the best quality/price solutions to that

Agreed. Flat roofs do not make sense where it snows, or in buildings that do not have large budgets to handle the complications internal drainage brings.

I think a lot of architects fail to realize the influence of a locality on the traditional structures that area. They think a style is a one size fits all solution. It is utterly stupid to have flat roofs on small or even medium structures in Northern Europe. As for roofs or even balconies that drain towards the center of the structure, I've never seen them not be a problem, even here in the middle east. That is just pure architectural ego and idiocy. Even Italy gets enough rain that most roofs are actually pitched.

@@UnbeltedSundew if wisely bulit, even factories and palaces are pitched at least a bit in Russia. You want the windows anyway, so the shape is close to a long relatively narrow rectangle, that may be twisted, but not too much. It has somewhat of a long peak the middle and here you are - pitched roof, large buliding.

Same problem in northern Italy, it's very rainy and snowy there and those flat roofs are a blight

Here Norway and I totally agree with your views. Problem is most designers and architects live in a paper or digitally simulated world and do not consider the million variables of the real world.

Yep.

if the majority of the water is drained then the rest will evaporate with the sun.

@@ajelicits3435 You get sun? Every flat roof residential building in Iceland has to battle leaks, many of them on just a couple of years old buildings. In addition to sun we get volcanic ash.

@@ajelicits3435 That's a good joke.

@@johng6350 the sun evaporates water. science bro

Similar for me. Our pitched roof hasn't had any repairs in the 50 years of our home has existed. The flat roof over the garage has had two replacements that I'm aware of, one from my budget. But in the roofs defence. You could put 10in of insulation on a flat roof it you wanted, it's just easier to retrofit that on a poorly insulated pitch than a flat. And our failing flat roof is a very basic construction over a space that was never meant to be lived in.

@@dwaynebailey333 not if it snows

@@dwaynebailey333 You are right about the poorly insulated pitched roof being easier. Two guys blew in the 10 inches in under four hours from start to finish in our 1280 sq. ft. attic. When it is blown in, it expands. I was shocked when I looked at the final product. It looked like a foot and a half of pink cotton candy. In terms of cost and comfort, it was one of the best investments we ever made.

Yep.

would you put a shingled roof on a stripmall, etc? as a flat roofer i know when and when not to put on a flat roof and a small building doesn't need it but large ones do.

Everything has its place. For a home with a small footprint, a gabled roof probably makes the most sense. For an expansive commercial building a flat roof makes more sense.

They were hugely popular in some parts of Europe during eg. 70s-80s but since there has been a trend to convert them to gabled roofs due to leakage issues.

You are correct, there are no true flat roofs, they all incorporate a fall (slope) to shed water to perimeter or valley gutters. In the UK the building regulations require a minimum slope of 1:50.

You are not wrong. The problem is how well and uniformly it is build. And the waterproofing of course.

If they were totally flat, the water would pool in several places and start to damage the roof. They have to have a slight slope (like a shower floor slope) for the water to drain.

Snow loading on flat roofs is generally a function of walls. In general because wind is a thing, snow will only pile as high as the nearest wall, and often not collect in the middle of the structure at all. The biggest issues happen when you tall inner walls extending above the roof line, such as mechanical penthouses or additional stories. Otherwise snow loading can be kept to a minimal with good parapet design.

@@jeremyO9F911O2 Depending on the type of snow. Especially in the spring with wet snow + rain we often see some colapses and have to go clear a couple of residential roofs every year because the snow load is exceeded. Sloped roofs also need a membrane to stop water from coming up the shingles due to "ice dams"

In my area, I see those sawtooth roofs in art and design-oriented buildings. I assume that the architect designed those roofs because the occupants of the building wanted natural light for their subject. And to your point, they almost always orient toward the south, where a more consistent amount of light is available.

A "sawtooth" roof probably has much higher heating and cooling costs, which is a much bigger factor in costs than modern energy-efficient lighting. Today it is cheaper to build with no windows at all, the money spend on lighting is negligible compared to lower up front costs, easier insulation and maintenance. Windows and skylights used to be required for natural lighting, but now its only used for esthetics, which is not a concern in industrial buildings.

@@denisl2760 windows are absolutely needed, otherwise one feels claustrophobic and probably starts suffering from something. (Poor health, high stress, circadian rhythm going awry etc.) There's a reason "the view" increases $$$, as it increases demand. Also, why cruise cabines overlooking the sea costing more than those sandwiched in between the layers. Also why tables on a restaurant/hotel adjecent to windows are often the most booked. Architecture used to be local. You could meet your fellow architect and builder next month along the streets. As such, there was a far bigger community connection. If he ripped you off, his reputation would be directly at stake. That all changed with fordism. There's no company today that does it all, start to finish. (Or a significant portion of it.) Instead there's company after company each "specialising" (read, pouring resources on the most profitable option they can still sell) on but a fringe aspect of a building, rendering the finished product completely impersonal. As such, it's mighty hard to fight the "vector of the industry" with its scale benefits. Becasue it's cheaper and able to be mass produced at a low cost. Which is also part of why "big projects" run costly. (Not the only one) They are trying to come up with "tailor made" solutions, effectively renouncing scale benefits. It's also why it's hard to build in a different style. So, really, the critique against architects is often missplaced. An architect today has budget constraints and industry forces shaping the range of his output. What is needed is just more art in mass production, shouldn't be that hard to mass produce some decorative moulds that make a city livable rather than soulless. But it won't happen until demand dries up for rectangular, oppresive boxes.

@@Untilitpases For residential space, absolutely. But here we are talking about huge warehouses and factories, esthetics are not a concern.

@@denisl2760 it's not a concern that people spend eight hours a day in an unhealthy environment? Light is not merely aesthetic. It's practical when it comes to the circadian rhythm. Also, direct gain (at winter angles) is a practical benefit of well planned windows.

People often just want things to look architectural and that has become flat roofs for some reason. Ridiculous. And this video did not convince me one bit. I'm both educated carpenter and architect and has worked as both. Flat roofs are fashion, not reason.

I see a lot of flat, concrete roofs in different cities in South East Asia. They seem to be fine! I love the idea of having a patio/deck on the roof.

That speaks more about how cheap warehouses are made, seeking reduced costs at every step, than it did about flat roofs. There are a lot of flat roof residential buildings. Some might be leaking at some point of time, but do you really think all of them do, and people just live in swimming pools?

@@jankoodziej877 For the same cost, flat roofs are more likely to leak than well sloped tile.

@@be12 but flat roofs are much cheaper, you don't need expensive wooden construction and the tiles. For the same cost you can get much better quality.

@@jankoodziej877 There are multiple carpenters on this thread saying the opposite. Unless you want a cartoon house roof with a 45 degree slope, of course. Flat roofs that don't leak are more expensive than tile roofs that don't leak.

@@be12 your don't need any carpenters for a flat roof, that's the thing.

Well in Florida you have to keep the slope/pitch of the roof down to a minumum as the primary concern is wind loading in a huricane and not much of a slope is neded to drain of rain water even in a heavy storm.

@@martinrwolfe Wind loading is actually worse with low slopes until you get to 35 degrees or so, because then the roof acts like a wing and the wind is constantly trying to lift it off the house.

Victorian houses had tall gables and CEILINGS to let the heat rise....no A/C back then.

Did ya get alot of rainfall there?

Of course - flat roofs are practical and dominant in temperate climates for the reasons you mention. But for those of us in the bold north, the reality of snow accumulation and it's inevitable melting, creates for much different considerations. Rainfall is not the same. Flat roofs are fairly common in the pacific northwest modern architecture where winter = rain, not snow. I assume the builders there have learned to master the direction of running water, and to consider how to leverage sun and wind to manage humidity impacts on materials.

@@DarkMoonDroid yes, but also a year around 18 to 27 Celsius degrees as average temps, water evaporates rather quickly, specially considering that the rain season is summer. The other half of the country is desert so that is a non problem, flat roofs actually help by being a space to put the AC units in that half of the country.

Flat roof are more common on warmer climates because it rains way less than colder climates, and back in the day people collected water by putting pots on the roof when it rains since every drop matters.

What you are saying is right from what I understand. But flat roofs are easier to maintain plus you get an extra space for your family gathering or gardening or doing other stuffs. Some people in my country makes a small room in the roof just to enjoy the beauty of the sky at night. We call it 'Chilekotha(চিলেকোঠা)'. So I think flat roofs have more added benefits. But some country like yours, gabled roofs are also a good choice but I like flat roofs more

I'm a flat roofer in the coldest areas of Canada and have never in my life seen a foot of ice on a roof. Snow yes but snow is mostly air. You just don't see that much ice because of heat loss from the building. Drains are also rarely unstructured by snow and ice. There's actually a lot of heat loss at drains so they tend to self melt. Leaves are always the enemy of every roof with controlled drainage. But they tend to collect more at parapets than drains because wind. A drain next to a parapet can therefore be an issue, but this isn't common placement for drains. And drains and scuppers are far easier to clean than gutters. For single story dwellings I agree that a gable roof is very practical but taller homes I would choose a certain type of flat roof membrane instead.

Around here, there are varying height limits based on your roof type, so that using a flat roof isn’t actually any better.

Tbf though a lot of those blocks we love to hate right now were vast improvements for the people who moved into them when they were built, you can try to convince the young Soviet couple who grew up sharing a hay mattress with 5 siblings in a house that leaked where the only heat was from the stove and there was no running water or electricity that their new apartment with water, heating and electricity is soulless all you want but they're probably going to think you're insane, or really spoiled. Like at the end of the day what matters the most to people is the basic amenities of their home, does it have water, heating, electricity and internet? Is it properly ventilated and does it get enough light? Is it actually large enough for their needs? Is it a reasonable distance from their workplace, friends and family? And so on and so forth, aesthetics is a nice thing that everyone likes to have but there's a reason why most people live in fairly boring looking houses and apartment blocks and that's because very few people will pass up a 2 room apartment with a decent rent for a 1 room apartment that is prettier.

@@hedgehog3180 Of course back when they were originally built, they may have enabled a significant improvement in terms of living conditions. But that doesn't mean that they are good by today standards, or that we should accept them as 'adequate' and not aspire to do any better. If everyone had that mentality we would still be living in caves. Most architects would literally consider it their job to make the built environment better. I'm not attacking soviet blocks as such, they fulfilled their purpose as you say. But we should be trying to do better in 2021.

A (truly) flat roof is a terrible idea - period! You can enjoy all the aesthetic properties of a flat roof with a roof that slopes a few degrees hidden behind a parapet - ideally draining towards the *outside* of the building. If it's a roof space that is to be used for regular foot traffic, then build a slotted deck over the sloped roof surface. Creating what is essentially a swimming pool over the top of a building is an idea that can only lead to issues down the line. I've lived in a top floor apartment where workers came to tear up the tiles on my rooftop terrace because water was quite literally *pouring* down the walls of the apartment below whenever it rained. In Sydney (where I lived at the time) this sort of issue was a monotonously common one, where lax building standards and profit-driven builders combined to make waterproofing one of several things that was done poorly.

@@danielscott4514 Just to be clear, when we talk about 'flat roofs' in architecture, we do obviously mean a roof with a nominal slope to allow drainage. All the things you said are correct, but they are all mentioned in the video, hence I felt no need to address them in my comment. I agree that a truly flat roof would be an absolutely terrible idea!

yeah, waking up and smelling the roses can be a real challenge when you've been fooled into thinking to narrowly from the start.

15 percent slope is absolutely fine thank god you did not get a flat roof they are horrible

HVAC worker here. I hate attics in the sloped roof homes!

And even in places like here in Finland, where we get loads of snow, it's often enough to climb up to the roof to clear away snow like two-three times a winter, sometimes just once, and it's usually not due to fears of the roof collapsing. It more a case of "let's fence off the area and deal with the snow before a pile falls on top of someone's head and kills them" Snow falling down from roofs uncontrollably is a huge problem for steep angled roofs as it will pile up anyway even if the roof isn't flat.

*systemic?

@ if you stab the rubber membrane with a knife, it will create a hole. This isn't because any of the systems which work together to keep water out failed. It is only because you stabbed the membrane with a knife. A systemic failure would be something like an adhesive that loses grip in heat or cold, or an edge design that lets water in, or maybe an insufficient drainage system that allows the weight of water on the roof to exceed what it's designed for. Correctly addressing whether a leak is caused by an incident or system failure is key to keeping the building dry. If you don't know how/why something works, the odds of making good decisions goes down fast.

Yeah this is something i wondered too- because you actually do find pitched roofs and gutter systems on cathedrals and castles. Many old 'flat/low pitch' buildings are no where near as flat as the roofs of modern high rises. Sure theyre not as obvious as the pitched house roofs but theyre not flat. What im saying is it should ve law to put gargoyles on council flats, lol.

This is also why it is common practice to shovel snow off of your roof in the winter. (Depends on weather, quality of the pack, and strength of the structure but usually more than a foot (.3m) is a getting dangerous) The easiest roof to clean is a sloped metal roof where 1 shove can clear an entire section (can happen spontaneously so be careful under sloped metal roofs in winter, especially tall buildings where it can pick up speed) Slopped shingles are also cleaned by just shoving but asphalt has a lot more grip than metal so you will leave a thin layer of snow behind and will have to push the entire roof area. And flat roofs are clearly the worst for this, first if all gravity doesn't clean them and won't meaningfully aid you. Second they have parapets you have to shovel the snow over. Basically imagine shoveling your driveway when it already has 3ft snowbanks, and a snowblower would save effort but may not be suitable for your roof (think of all the little stuff ontop of commercial buildings like wires and vents and whatnot). And you are right, the best roof is very situational, a log cabin an Alaska has very different needs for it roof than a Skyscraper in Egypt. But generally speaking commercial buildings get flat roofs as place for "ugly" HVAC equipment.

Sounds to me like that professor is a pretentious douchebag that hasn't produced a single billable hour in the past 30 years.

You mean he should have looked at how the Inuits built their huts/igloos in the icy windy and snowy arctic? I didn’t know Chicago had rounded/domed roofs

That sounds crazy unpleasant.

@@stewarthicks are you going to weigh in on the Munger Hall controversy at UCSB? Would love to hear your analysis.

@@aes53 Yes - I would like to see a video on this topic. I heard Munger funded a few other similar projects at other universities. I wonder how they turned out? Maybe talk to people who are staying in there...

@@photoviva8245 yes, me too, someone on Twitter looked up the size of a solitary confinement cell in penitentiaries and guess what, they are same size as the bedrooms in Munger Hall. Let’s brow beat Stewart to weigh in on it😁

@@aes53 I heard that students staying in his other structures actually liked living there, even if this is hard to believe. That's why is could be good to interview occupants of his other structures. Shocking to hear that he gave 200M, but the entire budget of the project is 1.5B.

Imagine a slant roof made of a single piece of corrugated steel, with zero penetrations - secured to the structure by (machine) welded threaded inserts. I'm sure it would be challenging to manufacture, transport would certainly be more difficult, installation yet more still... but you wouldn't have to worry about it once it was there! But modern houses are built to fall down two years after the mortgage is paid anyway.

​@@Bobo-ox7fj The problem is with a roof like that if you did need to replace it in case say a tree branch damages it would be even more expensive

Flat roofs are much better for solar panels in every way. The wiring is the cheapest, longest lasting, and easiest to install part of a solar installation. Tracking solar panels are far better than titles in every metric(although they are quite ugly). If Forbes is to be believed, "Tesla Solar Roof cost 48.9% more and yielded just 2.79% of the savings that the solar panels delivered." I haven't crunched the numbers myself, but as an electrical engineer, it is clear that Tesla roofs are not designed to be effective solar panels.

Comination and hybrids are usually the way to go

Hip roof?

@@cchastant8251 Two intersecting sloped roofs.

I think this is very context related.

They look pretty nice and give a lot of headroom, but in snow i feel they would struggle a bit compared to steep gables like the Dutch and Nowegian housing, which as well look proper cool, but the location defines the build

Maybe in a more arid climate. A proper tropical thunderstorm isn't a joke and flat roof is just not practical for that.

definitely a case of poor installers, and not reinforcing the structure for snow load. Here in Canada all buildings are designed for snow to be on the flat roofs. you should never have to remove he snow off a flat roof. for reference I have been in the flat roofing industry for 10 years.

Lol, the students probably damaged the roof during a probably unnecessary snow removal.