Why roof tiles exist. I understand why we don’t have flat roofs, but why do we have hundreds of tiles that sort of overlap each other and can be pulled or blown off easily?
Why aren’t roofs like a giant tent, still A shaped but each side is just a big sheet of whatever weatherproof material we got?
In: Other
Not every roof is the same shape. If you have to custom make roof sheets for every roof, it gets more expensive than just using a bunch of smaller pieces that you can cut into shape if needed, and these smaller pieces will be cheaper because of mass production. Also if parts get damaged, it’s cheaper to repair the damaged parts than installing an entire new roof. And finally because it’s easier to transport and install a roof if it’s in bundles of smaller pieces instead of one giant piece.
Making a single sheet for each roof is more expensive.
You need to make a single sheet. Custom fit it to each roof. Transport the single giant sheet somehow. If it breaks you need a whole new sheet.
Small tiles are infinitely scalable, no need to customize the size for each roof, and if a couple break you can easily replace them.
You could do that. One piece roofs are hard to manufacture, hard to transport, and hard to install.
Tiles can be mass produced in a relatively small factory, easily transported in bundles by standard vehicles, and are easily installed by semi-skilled workers.
Also, if it gets damaged you may have to replace the whole thing. You can just replace a damaged tile with a new one.
There is more to it than just weatherproof-ness.
Having a hard shell is usually preferred – a soft shell in the wind can move a lot, and most people don’t like that. Also prevents damage from things landing on it (branches, etc).
Second, smaller pieces lets the roof be more modular; it lets us reuse the same materials for differently shaped roofs, rather than needing custom sheets for different houses. It also is easier to replace a few tiles/ shingles that break compared to replacing the entire sheet or adding an ugly patch.
Mainly it’s because ….how would you build it?
There are many ways of waterproofing a roof. Asphalt roll roofing, shingles, tiles, built-up roofing, metal panes etc. Their construction are all a compromise between durability, cost, ease of maintenance and construction costs/feasibility.
When it comes to roof tiles. Clay is cheap and available and it’s also very durable. It is however quite heavy, and clay tiles are about the maximum size that clay that thick can be without risking it breaking under its own weight because you lifted it in one corner. The tile size also makes it relatively easy for a human being to construct the roof.
Like, how would you get an entire roof made from burnt clay in place? Because it would be prohibitively difficult and expensive to cast it in place. It would also be extremely expensive if you had to replace the entire roof because it cracked somewhere.
For the same reason asphalt rolls, another common roofing material, are a certain width and length because otherwise the roll would be too cumbersome to handle and handling it would risk damaging the material.
It’s hard to make a material waterproof. All it takes is a tiny hole and water can get in.
However, the neat part about roofs is that they mostly don’t need to be truly waterproof, as they are not submerged.
Instead, tiles or shingles can be used , which let rain and snow drip off of them. By layering them, you make sure there’s no way that water can go underneath them – since water doesn’t run uphill. Those Mediterranean terra cotta tile roofs don’t need to be impermeable to water, they are just layered so every tile drains water downhill to the next tile.
Up until the past century or so there weren’t that many truly waterproof roofing materials except for tar (which worked OK) or metal (very expensive and hard to produce large sheets by pre-industrial society)
Nowadays there are plenty of truly watertight plastic products that are affordable, but are not always super strong against mechanical damage (branches, hail, etc) so they are usually installed below a conventional shingle roof.
People think tiles look nicer than sheets. Many buildings do have flat roofs, and have sheets of material because people who can’t see the roof don’t care how it looks.
Replacing a few broken tiles is easier than replacing an entire sheet, even when only part of the sheet is damaged.
Tiles are good at keeping heat in and noise out.
They make roofs thats like what you are describing. EDPM rubber, (Ethylene propylene diene monomer). Basically just big rubber sheets that are joined together. You see them on commercial buildings alot although you might not know it at first, many are covered in aggregate (small rocks).
Small damage to a roof made of lots of small parts? Replace small parts.
Small damage to a roof made of one continuous part? Replace entire roof.
It’s not just rain you have to worry about: there’s snow, wind, hail, sun, and the occasional piece of falling debris.
That being said, **a** tile is cheap. That means any damage taken can be replaced in square feet rather than replacing an entire roof outright.
Latest Answers