In Seattle (Rain City) it's becoming more fashionable to have flat roofs. It may be because of height restrictions - people build up as high as they can to get the view.
Flat roofs always leak. My roof has a 45 degree pitch, as I hate leaks. I also replaced the asphalt shingles with metal, because metal is lighter (less earthquake damage), doesn't burn, and will last the rest of my life.
Another oddity around here is vanishing eaves. My house has 2 foot eaves. This keeps the exterior walls dry, and they last a lot longer. Keeps the windows from rotting, too. And the house shaded in the summer.
New houses are lucky to have a 1 inch eave. I don't get it. Eaves are one of the cheapest ways to reduce maintenance costs.
Up here in Vancouver, they decided to start counting the area under the eaves as part of the permitted square footage back in the '90s. No surprise, eaves immediately disappeared from new construction and we had a decade of water damaged buildings that needed expensive remediation.
Some of that was inappropriate materials (EEFIS?) and really stupid detailing, apart from the Eaves thing. Essentially, the water would collect inside the wall and rot out the structural support. When I was a civil engineer in the Pacific NW, our company had a rule: No work on condos. Not worth the risk.
> It may be because of height restrictions - people build up as high as they can to get the view.
Here in London, a flat roof means you can add on an extra floor (raising the property value) without towering above adjacent homes (which would make it hard to get approval to build)
Does it leak? Not in the first few years - and if you're a house builder, anything after that is the buyer's problem.
Exactly. Depending on where you live it’s hard to impossible to get permission to go above the existing ridgeline of the house, leaving people to poke flat roof dormers out the side.
Flat roofs don’t have to leak. I’m doing an EPDM roof on my garden office at the moment. It’s a single huge sheet of rubber.
As others have pointed out, the lack of eaves is the real killer. My dad was over from NZ in the summer and he was saying that fashion is there too. It’s causing all sorts of water issues for buildings.
There is one style of flat roof which is designed to hold water, with gravel on top to protect the rubber. Apparently very good, but you have to get it 100% right.
Flat roofs also bend a lot more under snow load. This bending opens up cracks in the roofing material - i.e. leaks.
I had a garage with a flat roof once. There was a big snowstorm. So much snow landed on the roof that it bent so the doors wouldn't open. After I got on it and shoveled for a couple hours, the doors would then open.
Another thing are gutters that require constant maintenance, and fail anyway. With good eaves and correct drainage around the house you can build without gutters like they did for centuries, and eliminate this finicky maintenance problem.
None of the responsible architects, nor developers, nor builders, nor Realtors pay those maintenance costs. And most of the folks buying houses these days are either indifferent, or oblivious, to the problem.
I've had my house for 25 years now. There are a lot of inexpensive details in it found nowhere else that have paid off handsomely.
For example, the washer and water heater are in the basement. The concrete floor under them is slightly sloped, leading to a drain. I've had multiple failures with washing machine hoses and leaks, and leaking hot water heaters. They resulted in zero damage, unlike in other places I lived.
Another one is Seattle homes always have wooden decks. The decks rot after a while, sometimes killing people when they collapse. The rot comes from being endlessly damp, and the local ants nesting in them. The last such deck I had I sawed off of the house, and it collapsed into a pile of sawdust. I was horrified.
So my current house has a concrete deck. Yay, no problems at all!
Here's another goodie. Never, ever, ever have the driveway slope towards your garage. Your garage will inevitably flood. A gutter in front of the door won't help, as it will clog with leaves, sticks, ice, and slush, and your garage will flood.
Also have the garage floor slope ever so slightly towards the door. The only way you can tell mine is sloped is its a lot harder to push the car into the garage than push it out. The slope helps if a car has a major malfunction, and you don't want oil/gas/antifreeze soaking into the walls.
What was weird is the architect and the general contractor were completely uninterested in these things.
There were still mistakes. The bathrooms have MDF baseboards. Whaddya know, MDF swells up when it gets wet. It all needs replacing. The GC should have known better. MDF also swells up with cat pee. OMG. I'm currently tearing that stuff out and replacing it with wooden baseboards.
I should write a book - "Things Your Architect Doesn't Know and Your General Contractor Won't Tell You"
My previous house had two structural weak spots that resulted in the house bending and sagging. I identified one in this house as it was being built and had it fixed. Being a mechanical engineer has its advantages! I discovered that architects know nothing about structures. The structure was also compromised when the plumbing was put in, so I worked with the GC to design a fix.
I think its better to design the bathroom to deal with the moisture instead of wasting energy baking out your bathroom. Crack a window or leave the vent fan on.
Cracking a window doesn't help if you live in a damp climate. My bathroom is in a basement so the vent fan would just bring in more damp air. The heat isn't to bake out the moisture but to force it to disperse.
While most people came to Walter to ask about programming languages and their design, or Empire, you knew better and focused on his true talent: tactics and strategy of North American residential structures.
Haha, I'm a born engineer and am always redesigning things in my mind that I encounter.
Being able to influence the design and construction of my house was immensely satisfying. Both the architect and the GC thought I was nuts with a lot of the ideas, but since I wrote the checks I prevailed.
Another one was the counter tops were inches higher than normal. They're just easier to work on that way, and the bonus was they were too high for The Cat to jump on. I also hate kitchen islands, and so don't have one.
A big mistake I made was not making it wheelchair accessible. That would have cost nothing extra, but I know people who had to remodel their home or were forced to move because they got stuck in a wheelchair.
It's fun doing this stuff. I read a book years ago "Common Sense Pest Control" which remarked that the highway for termites and bugs are the cracks in the foundation walls, which they climb up and then bore into the wood framing. The cure was a stainless steel sill plate (it's usually just a piece of plastic). So my house has a stainless steel plate there. The GC thought I was an idiot. But it works, and it's not like you can add it after the house is built.
I did the low voltage wiring myself because the electrician didn't understand it. Every room has 2 sets of cat5 and RG6 coax. Wifi has improved considerably since then, but I still enjoy the reliability, privacy and speed of wired connectivity.
GFCI breakers on all circuits in the circuit panel.
I failed to add wiring for a generator, this later turned out to be an expensive upgrade. Puget Sound Energy uses overhead wires, which fail regularly.
French drains around the basement, as a damp basement is a relentless horror.
Have you ever scraped the bottom of your car pulling into a driveway? I have. I told the concrete contractor to not have any abrupt changes in slope, and if my car scrapes he's going to have to redo it. He laughed, and said no problem. And it was no problem, he did a beautiful job just as I asked! The neighbors scrape their cars on their driveways.
Another little thing is the edges of the driveway are rolled up an inch or so. This means you can back up, and know when you're at the edge by the feel. Nobody else does that. This is so valuable because of the slope and soft ground off the driveway - you'll get hung up if you drop the wheels over the edge.
The house is designed to make use of the "stack effect" to keep it cool in summer. It works ok, but it could have been better. Houses used to be built to be naturally warm in winter and cool in summer, but the advent of A/C has caused it to be forgotten.
Oh, and fire sprinklers. I did a search and could not find any instance of people dying in a sprinkled building fire. They're expensive though. Ouch.
Thanks for sharing all of this, typical HN at its best. Off the top of your head can you think of any other books like "Common Sense Pest Control" that served you well in a similar capacity?
Thanks for considering it then, and yes I totally agree. Depending on circumstances, I'm not always sure that I'm accomplishing anything when weeding the yard without pesticide.
At my current Seattle-area house I have an area laid out with paving stones instead of the deck and it's great!
Another pro-tip for Seattle is never buy house on the bottom of the hill or on top of the hill (yes, this only leaves hill-side). On the bottom you'll always be flooded during the winder, on the top you'll get crazy winds and rain banging during the storms.
Also get a soils geologist to evaluate the hill behind your house. $300 will save you a zillion if the hill gives way and engulfs the house. Or having the house slide down the hill.
> For example, the washer and water heater are in the basement. The concrete floor under them is slightly sloped, leading to a drain. I've had multiple failures with washing machine hoses and leaks, and leaking hot water heaters.
In Japan I saw a washer in the 2nd floor of an apartment sitting on top of what looked like a shower basin. If the machine leaked it is caught by the basin. Granted that will not stop a leak in the water line from spraying beyond the edges of the basin but something like shower stall walls could mitigate that.
Two of my washer leaks were spraying out sideways. First the hose had split. I switched to braided stainless lines, and then the brass valve on the wall split.
Besides, who needs the dang noise it makes. Banish it to the basement.
I grew up with washers in the basement and only ever put them there. Though washers on the same floor as the bedrooms sounds more ergonomic. I suppose you could simply make the washer room a shower closet complete with floor drain, tiled walls with green sheetrock but cost goes up and exercise goes down ;-)
If I were to design/build my own house the first thing I would specify is that EVERY room with designed water ingress (kitchen/bathrooms/mud room/workshop/washer/dryer/water heater et al.) must have a floor drain. Over the 41 years I've lived in my 1967-built house I've had too many replays of repainting downstairs ceilings after bathtub overflows on floor above....
This may be a generational thing, I am GenX. I grew up my entire life hearing "Flat roofs always leak" from the men in the family (none of whom were roofers). Their generation had strong opinions on the right way to do things (This applied to anything). I miss them and I am sad they are gone.
Many people will tell us flat rooves perform no worse under a given load or precipitation condition than pitched rooves, they both just have to be designed right for it.
But if flat ones are harder to design right, then they're more likely not to be designed right, so we end up with a larger number of edge cases where they're going to perform worse.
We have a similar weird thing going on over here east of the mountains... building generic suburban houses with wood in a climate that a) has no trees (IE: materials have to come from far away) and b) because it's desert, really would benefit from design that better channels heat and breezes through the house. So point being much like flat roofs in rainy Seattle, builders / architects are not actually building for the local climate.
“Much of the social history of the Western world over the past three decades has involved replacing what worked with what sounded good.” - Thomas Sowell
"Much of the social history of the Western world over the past three decades has involved replacing what worked with what sounded good. In area after area - crime, education, housing, race relations - the situation has gotten worse after the bright new theories were put into operation. The amazing thing is that this history of failure and disaster has neither discouraged the social engineers nor discredited them."
So how much you agree with the applicability of the quote might depend on whether, say, you think the education and race relations in 1993 were better or worse than they were in 1963.
Somehow I suspect that people have been saying this about flat roofs dozens, maybe hundreds, of generations before Sowell was born. It's not like multiple roof-types are a 20th century invention....
However we used to build houses in very regional styles. Flat walkable roofs in the middle east where it barely rains. Angled roofs in rainy Europe. Steeply angled roofs in snowy Sweden and Norway. Constructions that encourage drafts to form in houses in the Southern US.
Now, especially in the US, we just build the same types of houses everywhere.
Reduced eaves reduce the possibility of ice damming and AIUI, make it easier to air seal the building envelope between the walls and the roof. Note that that's an air barrier, not a vapor barrier. The air barrier is pretty universally done outside of the insulation, whereas the vapor barrier location depends on the climate you're in.
As you note, this does come with tradeoffs, like most things.
Not a builder, nor do I have any particular knowledge of building science beyond reading Fine Homebuilding.
I have a flat roof in Seattle -- no, flat roofs do not always leak. But they do require you keep your drainage clear (something a sloped roof homeowner can get away with ignoring).
Modern membrane roofs last longer, leak less, and are more energy efficient.
Are you sure about energy efficiency? A properly designed peaked roof can make use of the "stack effect" to keep it cool. The slope accelerates the breeze, and sucks the hot air out of the ridge vent (or cupola). The attic still gets hot, but that gets hot instead of the upper floor.
Asphalt shingles are awful in terms of insulation. They absorb heat in the summer and bleed heat in the winter. Membrane roofs are better for both.
Asphalt shingles are such an out-dated technology, people should really try to avoid them on new builds. They don't last long, the thermal characteristics are bad, and they're prone to leaks.
Also all the rooms have at least 2 opening windows so cross-ventilation works. It's pretty obvious - open one window and nothing happens. Open both, and ahhhhhh!
The shingles are nailed at the top, and the overlapping one keeps it dry. (On mine, they're screwed in.) High winds could drive the water up under the shingles, but that happens rarely so they aren't kept wet.
Anything that goes through the roof disrupts this, so skylights, vents, chimneys, fans, antennas, etc., all are points of concern.
Look up "seamless metal roof," where the screws are installed beneath the sheathing.
Most metal roofs I've installed use rubber-gasket-screws, but clients that can afford "seamless" do [it will shed water indefinitely, with no screwholes to eventually leak].
The metal shingles in mine have grit bonded to the metal, so one can walk on the roof with much less risk of slipping off. Since it's a recent innovation, I knowingly took a risk on it. I suppose over time the grit will come off, but that won't cause a leak.
The asphalt shingles will crack over time, and crack when you walk on them, leading to leaks.
I hate the cedar shake roofs, because they mildew and wasps nest in them.
Some things I was warned about but did anyway. The insulation is icynene foam. Some foams disintegrate over time, but this one has not at all. It's far more effective than fiberglass, no breathing in fiberglass, no mildew. I'm very pleased with it.
I think even if people did not have height restrictions they would still be plenty attractive. It's why balconies are also everywhere; people like outdoor space, and if you don't have much of a backyard to speak of your options are sideways or out.
most of the new Seattle flat roofs are townhomes with no backyard to speak of, because there are townhomes where that would be.
So I live in one of the mentioned flat roofed houses. We restored it to its original appearance, but with very modern internals (proper insulation, heatpump, wall and ceiling heating areas, KNX-based smart home, etc.). It’s a piece of art on 110sqm, with very practical floor plan. To optimize space and material, every single wall has optimized thickness. Really impressive attention to detail some 100 years ago. Oh, and the roof has never leaked… (2.54 degree pitch btw)
I was surprised to see 0 results for “leak” on this article. Frank Lloyd Wright’s houses were famous for having flat roofs and leaking. Anyone know whether these flat roofs suffered the same fate?
I've actually been in the Johnson Wax FLW building in Racine. They are still using it, but I believe it had problems to overcome, like most FLW buildings.
I don't remember if it had a flat roof, but probably most office buildings did.
I live a couple blocks away from there. The roofs are flat in that whole complex aside from the Golden Rondelle Theater. I don't know if they've since fixed it since I see they've done some redecorating on the upper floors in recent years and I haven't thought to ask anybody who works there, but for a long time they couldn't have people working in a large portion of the central tower due to inadequate fire exits.
knowing nothing about construction, architecture or engineering, i've still heard enough anecdotes of that + common sense would seem to dictate that if your roof isn't sloping (even a little bit) you're gonna have more problems with rain (which can freeze and open cracks), let alone snow (which can be deceivingly heavy even in small amounts) or even other precipitate like dust, sand, leaves, what have you
i would be perfectly fine with regulators enforcing sloping roofs by default and only allowing flat ones if you explicitly and deliberately apply for an exception
it would save lots of unknowing homeowners easily preventable problems stemming from flat-roof McArchitect homes that look modern but aren't practical, and allow the ardent individual flat-roofers (lol) to get what they want if they absolutely must
I mean, most commercial and industrial buildings are approximately flat on top. There's some pitch, but its pretty minor. Its basically a solved problem, and a qualified building inspector would know how to inspect for the requirements of that particular roof style. Its unambiguously a higher-maintenance style, but it's no worse than having wood siding in terms of annual maintenance labor. Just that the consequences of failing to keep up with the labor is a lot worse.
That said, when people start throwing gardens onto their roofs, or otherwise doing things that the roof was not originally designed for, things get iffy.
Our 800k sq ft factory has a "flat" roof. It has drains all over it that feed straight down into the building and below the concrete to a massive storm water drain.
Very interesting, but it seems like a symbolic debate among folks who were somehow involved in deciding the shape of a roof or who were already invested in a larger social debate.
Random every day person, were they aware of this debate, and did they actually shop for housing based on roof shape?
I think you should understand this in the light of e.g. freedom fries and Trump's executive order re: "beautiful" public buildings. That is, once you're in a culture war, the dumbest things become battlegrounds.
Its also important to understand that the buildings in question were meant specifically as worker housing, so it was a collective project funded by workers' unions, each with particular ideologies. If you were part of the liberal housing co-op that advocated for flat roofs, you were gonna live in the flat-roof buildings. That is to say, you didn't express your politics by choosing your roof, rather, you chose your politics, and your available roof shapes were informed by that choice.
> the architect Walter Gropius, a well-known flat roofer and ostensibly Tessenow’s opposition, insisted “the question of whether a roof is flat or pitched is to be answered solely on the basis of practicality, technology, and efficiency.
hey Walter: have you heard of snow? It's known to fall in Berlin. Not so much in Jerusalem.
>the question of whether a roof is flat or pitched is to be answered solely on the basis of practicality, technology, and efficiency
No. The aesthetic dimension to architecture is critical because buildings constitute our environment and affect our psychology and how we interact with one another.
Would you rather have lunch in a beautiful piazza in northern Italy, or in a purely functional American strip mall / parking lot?
Would you rather live in a cozy cottage in the Cotswolds, or in a commie block in Petrograd?
Should a courthouse reflect the majesty and seriousness of its purpose, or should it reflect the ridiculous dadaism of a peculiar architect?
Buildings are not merely functional and they are not merely art. They are the environment that conditions the daily experience of the community, and because of their persistence and constant action on the public mind, we should take care how they form a home for civic life.
So what? All you need to do is make sure the structure can support the weight of the added snow load. Which entirely falls under the rubric of "practicality, technology, and efficiency".
How is it efficient to make design choices that increase the strain on the structure, forcing you to add extra strength that would not otherwise be necessary?
It wouldn't be efficient if the only thing a flat roof bought you was added strain. But, for the most part everything is a tradeoff. Maybe the practicality of extra floor or head space is worth increasing the strength of the structure.
That's not all you have to do. I'll let people who've owned houses in snowy climates amplify that.
In a building, water is your eternal enemy. Keeping it out of places where it doesn't belong accounts for a good part of the other things you have to do.
Practicality aside, another major controversial opinion of the Nazis was that buildings should be beautiful. There's a lot of ugly communist architecture in Europe that shows which side won the war.
Though the common modern understanding of it does lend itself to 'brute'. I think one of the real issues was the post WWII era of 1950s to 1980s was a time of focus on low cost construction with an overconfidence in the forgiving nature of concrete combined with a fair amount of corruption in the factory supplied components - at least in the UK which I'm more familiar with.
It can be done well, and I point to the Barbican in London as an example. With better construction techniques it can last a lot longer with less maintenance cost.
To me, this looks more like an East Berlin apartment building for the Communist Party elites. Not as ugly as the workers' buildings, but that's not saying much.
> Brutalism is an architectural style of the 20th century that mainly uses concrete as a building material. The term "brutalism" comes from the French expression "béton brut", which means "raw concrete".
The socialists thought their architecture was beautiful as well -- both aesthetically, and because it was produced efficiently and served the needs of the people. And in fact they produced many perfectly fine and beautiful buildings, some of which are quite coveted residences today (such as the apartment complexes near Frankfurter Tor in Berlin).
Meanwhile pretty much the worst architecture you'll find anywhere would have to be the strip mall architecture (and most office complexes, and much suburban housing) created in the U.S. from the mid 1970s onwards (up until then it had at least some semblance of style). And now basically copy-pasta'd all over much of the world.
In my view it's arguably even uglier, because it symbolizes a system in which people thought they were more free, original and infinitely wealthier then their counterparts in the supposedly drab, miserable, totalitarian East. (It was all those things to some extent; and folks in the West were categorically more free -- just not nearly to the extent that they typically thought).
In fact, so deeply threatened were the new overlords in the West by the very idea that the socialist system could also produce beautiful and vibrant public spaces that they felt they just had to destroy one of its crowning achievements (the Palast der Republik, also in Berlin), and at a stupendously great cost -- and replace it with something basically garish, entirely fake (by design), and far less inviting and useful -- just to make a point.
> In fact, so deeply threatened were the new overlords in the West by the very idea that the socialist system could also produce beautiful and vibrant public spaces that they felt they just had to destroy one of its crowning achievements (the Palast der Republik, also in Berlin)
The GDR used 5000 tons of sprayed asbestos even though it had been banned since 1969 even in the GDR but they exempted this new project. That is why there had to be a huge asbestos removal project. It was sprayed directly onto the massive steel construction, so not easily removed. Only the bare steel shell remained at the end.
However, the argument is that they did not have to remove the Palast entirely and could have rebuild it after asbestos removal. I was inside as a GDR teenager, it sure was an impressive looking building. I'm not sure how political or technical the final decision to go ahead with its demolition was, too late now anyway, and I don't feel all that strongly about it even as ex GDR citizen. I think given that they had to pretty much completely dismantle the whole thing down to the steel skeleton makes it hard to fault them for going that one step further. The article I linked makes an argument that it should have been kept and used.
The articledoes point out though that three different Bundestag legislatures all overwhelmingly voted for the demolition, with three different sets of parliament compositions, so that it definitely was a democratic decision, and it came after lots and lot of public discussion. Even the article, voicing a different opinion, concedes that that was the case and that the democratic process was "exemplary".
That's why I think you should be careful using this example the way you did there, I don't think that the description of how that happened supports such a claim. One also has to point out that it was supported by plenty of people from the ex-GDR too, this wasn't dictated by the West Germans.
Well yeah I was being slightly polemic in my narrative, if you will. And of course there were varying opinions on all sides of the former border.
But being as the issue was decided by Bundestag, that would mean it was ultimately decided by Wessis, by definition. Largely on the basis of it a "symbol of the Dictatorship" (and as a snub to Gysi) and all that. And as far as public opinion in the East was concerned -- I don't know if it's the last word on the matter, but we do have this one poll result at least:
Nach einer Umfrage der Zeitschrift «Super Illu» lehnen 60 Prozent der befragten Ostdeutschen einen Palast-Abriss ab, weil damit «wieder ein Stück DDR-Geschichte plattgemacht wird». Zugleich sprach sich die Mehrheit aber für eine dauerhafte Grünfläche anstelle der historischen Schlossfassade aus. Befragt worden waren 1005 Menschen in den neuen Ländern. (tso/dpa)
"major controversial opinion of the Nazis was that buildings should be beautiful"
That's not controversial my friend. They should absolutely be beautiful. This is a belief that has been held for thousands of years up until the advent of the late 20th century.
> This is a belief that has been held for thousands of years up until the advent of the late 20th century.
The belief has held through to today, too. The difference is that there was a huge explosion in the global population - especially the middle class - to the point that all the crappy houses and apartment buildings people could actually afford to live in vastly overwhelmed the buildings with pretty architecture.
Look up stalinist architecture if you think communists can’t build beautiful buildings. For peak capitalism, look no further than Art Deco. My point is that this is a difference between pre-war and post-war construction and is seen in all regions, across all political ideologies and economic systems. The ugly communist buildings you speak of were born out of necessity, due to chronic shortage of housing, a rise in fertility and urbanisation on a scale never seen before, much the same way as the urban catastrophe that is suburbs in the US.
It still is in most parts of the country: the type of roof and even the type and color of the tiles are mandated in most areas (through the infamous Bebauungsplan)
The Europe is full of centuries-old buildings with pitched roofs which routinely survive naturally happening periods of light/neglected maintenance. Whereis any flat-top building will most probably fail without regular roof maintenance.
Many of them also have slate roofs. Slate's not going to suddenly start leaking unless it's cracked. Contrast that with roofs in the US that use asphalt that needs replacement every couple of decades.
In a childhood i spent some time on an old German farm with a main house and a barn. I crawled and climbed everywhere in the both buildings. Both buildings are of the same high quality of build - brick and stone walls, pitched red ceramic slate roofs, large wooden beams - that is tested by and evolved over long time. The only noticeable difference between those 2 buildings was that the barn had less windows, and the first meter of its wall height was made out of the larger stones fit tightly to each other whereis main house wall were fully brick and such stones were making only the foundation - thus the barn walls were about 2 times thicker at that lower height part. I didn't see any metal in the construction - in the attic the wooden beams were dovetailed in the joins and the joins were pierced by large thick "nails" made of hardwood. Smaller members were tightly dovetailed to or sat in the grooves of the larger members - all the way down to the planks which formed the sides and the floor of the attics (and the second layer of planks about 4 inch below the attic floor planks was the ceiling of the first floor - again sat tightly into the grooves of the large beams).
I lived in this borrough for most of my childhood. Never knew about this dispute though. The Onkel Tom settlement is really beautiful. It comes with an underground station with an integrated shopping mall -- a novel concept back then.
Flat roofs always leak. My roof has a 45 degree pitch, as I hate leaks. I also replaced the asphalt shingles with metal, because metal is lighter (less earthquake damage), doesn't burn, and will last the rest of my life.
Another oddity around here is vanishing eaves. My house has 2 foot eaves. This keeps the exterior walls dry, and they last a lot longer. Keeps the windows from rotting, too. And the house shaded in the summer.
New houses are lucky to have a 1 inch eave. I don't get it. Eaves are one of the cheapest ways to reduce maintenance costs.