Why do houses have shingles and slanted roofs, but most other buildings have flat tops?

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Why do houses have shingles and slanted roofs, but most other buildings have flat tops?

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Anonymous 0 Comments

A shingle roof is a very cheap, very efficient, easy and reliable method of waterproofing a building. Tile, slate and terracotta are also similarly effective but more expensive. The sloped roofs also keep things like snow to lower levels.

A flat roof normally requires a more thoroughly waterproof system, as it can actually hold water, and more robust maintenance. They’re more complex to install, and if the waterproofing part is exposed to the elements they have more maintenance issues than a shingle roof. None of this is great for residential use.

But for larger commercial buildings it makes sense. The buildings are so large that a sloped roof would add significant height and construction expense while adding loads (cost) to the rest of the building. These types of structures also normally like to have mechanical systems on the roof (AC, Chillers, Air handling units, etc) as this doesn’t take away from leasable space inside the building. To build these on the roof you want a flat roof.

Anonymous 0 Comments

Rain moves down off the slanted roof to prevent pooling and leaks, a larger roof is difficult/expensive to build with a slant so may have a generally flattish roof with a slight slope with drainage system removing water from the middle of the roof.

Anonymous 0 Comments

With a slanted roof, the larger (wider) the building, the taller the roof would have to be. a large building would have a very tall roof. Imagine a walmart with a slanted roof. The roof would be 100 feet tall.

Also, shingles are more expensive than the waterproof membrane they use for a flat roof. If nobody cares what the roof looks like, (or if nobody can see it) a flat roof a much cheaper option.

Anonymous 0 Comments

Biggest 2 reasons is for:

* Significant added cost to make sloped roofs on commercial buildings
* Imagine the cost of making a sloped roof on something like the new Giga Factory in Texas. Also, the slope space is practically useless for something like a warehouse or factory.
* Mechanical Equipment (ACs, chillers, heaters, etc…)
* Easy installation / maintenance – with the size of most of this equipment, it would be a nightmare trying to install / service the huge AC units on commercial buildings with a sloped roof on it…

Anonymous 0 Comments

Snow, mostly. A flat roof will pile on snow until it collapses while a slanted roof will eventually have the snow slide off. However, the slanted roof is more expensive as there’s more roof surface to build. Thus we see flatter roofs in hotter climates and pointed roofs in colder climates.

That being said, home owners often prefer one style or another and modern building techniques means that you don’t necessarily need a pointed roof to keep the ceiling from collapsing.

Anonymous 0 Comments

Shingles are surprisingly durable and their multiple layers give some redundancy

Flat roofs are common on commercial buildings because it gives you a place to put your equipment like large HVAC gear or elevator equipment that needs to protrude out the top. A trade off for being “flat” is that they actually need to slope inwards towards a drain pipe that will transport rain/snowmelt off the roof, and they need to be a lot stronger to deal with the added weight of snow on top

Buildings further from the equator tend to have more slanted roofs to keep snow from building up. Slight slants on a roof can shed snow, but if you’re at risk of getting 36 inches of snow overnight then you need a roof that will physically shed snow regardless of the suns input and that why houses in the US North East have much steeper slants on their roof than houses in Texas and the like where snow is less common and less severe

Anonymous 0 Comments

ive been told that flat roofs in high population area let you control the flow of water going to the drains. if all roof were slanted there could be a overflow.

Anonymous 0 Comments

Before the modern rubber membrane flat roof or the asphalt, tarpaper roofs, buildings that would have a flat roof like a factory had “saw tooth roofs, a succession of small sloped roof with vertical glass window walls. This had the advantage of also being able to add skylights to bring light into the space. https://en.wikipedia.org/wiki/Saw-tooth_roof

Anonymous 0 Comments

I watched this (https://youtu.be/QW0ydAMVQ2w) that delves exactly in to this topic but it’s not an ELI5 video per se

Anonymous 0 Comments

r/montreal meetup at the open house? lol