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Comment by dylan604 | Hacker News Reader

Where do you live that a building of modern construction is supported by bricks? In the US, multi-story residences are built on wood with a brick facade. Multi-story commercial buildings are built using wood up to 4 stories (depending on locale), and steel after that.

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The US is the odd one out... I completely see why you'd make a temporary building out of wood so that you can build it in just a few days.

But if this is a house, expected to last 150 years plus, and you're already bringing lots of bricks to the site, you really ought to be using the bricks to hold the building up and reserving the wood for the internal floors and other things that will be replaced every 75 years.

We don't use bricks for structure any more because earthquakes. Wood buildings fare much better when shaken. We also have plenty of wooden houses that have stood for 150 years.

Wood lasts 150 years plus. There are environmental factors that, unmitigated, can damage wood. But the same is also the case for masonry construction. They both have their pros and cons. And now that things like vinyl siding exist, wood homes can last a long time even with minimal maintenance.

Just FYI, Hōryū-ji is a temple built of wood that has lasted 400 to 1300 years (parts have been repaired over the centuries). It's all about how you care for the building.

https://en.wikipedia.org/wiki/H%C5%8Dry%C5%AB-ji

A bit off topic but wood houses can, if done right, last quite a lot longer than 150 years.

The oldest timber frame house in the US dates to 1637.

Wood easily lasts 200+ years as long as it’s thick and dry. It tends to sag over time, but most buildings end up being fairly temporary on those timescales.

Wood houses can last just as long if they are properly built and maintained. I will grant you that many buildings in the US aren't built or maintained to last that long, but they can and do exist and it is what most builders would prefer to build if there was the demand. Wood is also much easier to repair if there is damage, or easily jacked up if the foundation moves over 100 years.

Bricks are not nearly as strong as you intuitively think. They do great in compression, but terrible in tension. Bricks are also terrible insulation. Real structural engineers take this into account, and thus often use wood or steel (or other materials) depending on what really matters. And of course the entire structure needs to be designed as a whole.

Unreinforced masonry is weak in tension because of the weak binding interface between the masonry unit and the mortar. The reason masonry is used in wall construction and not in, say, a suspended floor, is precisely because walls don't typically experience tensile forces. Any tensile force resulting from e.g.: wind loading on the entire structure is typically overcome by the self-weight of the masonry.

If there is a special case where tensile forces are expected, for example a retaining wall, or a mid-rise structure, or earthquake load, the engineer will specify the the masonry is reinforced with steel and then it can resist tension through the unit/mortar interface just fine.

It is a poor structural engineer who tells the architect masonry isn't an option because tension.

The tension is resisted via the steel, not the CMU/mortar interface. Masonry behaves similar to concrete (that’s what the C in CMU stands for...) and suffers from the same issue as concrete re: lack of tensile strength. It is not the mortar interface which makes masonry a problem for tensile loading conditions but the structure of the masonry and mortar itself. They simply are not amenable to carrying tensile load at a microscopic level.

I don’t know what structural engineering you’ve done or what jurisdiction it’s in, but for practical purposes on the west coast in America, structural masonry isn’t an option beyond maybe 3 stories because of tension (due to seismic demand) and any structural engineer that says otherwise is looking to get sued for negligence.

Elsewhere in America this is less true but still most modern engineering doctrines would lead you quickly away from masonry for anything substantial, although cost and schedule is obviously a key factor in masonry’s favor.

Everything else about the use of masonry in walls I generally agree with, although the move away from allowable stress has impacted it as described above. Except maybe I would quibble about the use for retaining walls. CMU can be particularly cost effective for some geometries of retaining walls when used with steel.

You can build wooden house that would stand 100+ years. Not US-style houses from planks, though, you just cut trees and use their trunks as a whole to build walls. Also you should protect it from the rotting.

There are a very large number of 100+ year old wooden homes in the eastern half of the US. Check out Zillow with the "year built" filter. Even if you set the filter to limit results to 1899 and older, the vast majority of homes are of wood construction.

Heck, I live in a 91 year old wood framed and clad home in California - this isn’t limited to the east coast.

This house is going to outlive me as well, barring a natural disaster (which it is better suited to withstand than a masonry home, given that my most likely disaster is an earthquake).

While sibling comments mentioned a bit about differences in building approach with heavy use of brick and concrete in Europe, at times it reaches into cultural incomprehension.

When US action movies started to show up more in Poland, many people joked how american movies exaggerate things by using cheap plywood scene sets for houses. Finding out that american homes are actually built like that was a bit of a shock to many.

To be fair, a little 4.9 earthquake counts as one of the biggest ever recorded in Poland.

And if you know anything about electrical wiring, do not look up how they do it in those plywood houses in US, any European building inspector would have a heart attack :)

I get shivers just from the standard outlets in USA...

What's wrong with our outlets? We've got less voltage, and a ground plug that makes contact first. When the outlet is in a room with water, or outdoors, it goes through a ground fault interrupter to keep people from being electrocuted.

We reserve 220 volt outlets and higher voltages (3 phase 480, etc) for the larger loads, and those plugs are huge, and not something found in a typical home.

While this is all true, less voltage comes with a price and that is more current.

2 times less voltage === 4 times more heating for the same resistance (heating is calculated from R times I^2).

This means that short circuits, wiring problems are potentially much dangerous.

I live in Poland. Almost all buildings outside cities are bricks with bricks being load-bearing.

In cities, almost all buildings older than 1950 are also made from bricks.

Central Europe mostly builds from bricks. Not just classical red bricks, Ytong is a very popular type too.

Wooden structures copied from Scandinavia are slowly coming into fashion for smaller family houses (the construction process is very fast compared to bricks), but they are still very much in minority.

Taller constructions are concrete + steel.

> Taller constructions are concrete + steel.

There have been some advancements in wood for taller structures in recent years. Basically they have come up with wood that is as strong as concrete.

Main problem is fire/pests/rot/etc so you can't build crazy big but there are now 7 or 8 story tall apartment buildings made out of wood mainly in Helsinki for example.

Making apartment buildings out of wood is also much more environment friendly then concrete (somewhere around 50% less total co2)

Structural wood can be more fireproof than steel.

I saw this in an excellent exhibit at the National Building Museum in DC a couple of years back. Will try to track down a reference.

Some discussion (and dead links) near the bottom of this thread - https://news.ycombinator.com/item?id=16331375

Fennoscandinavians are very good with their wood. (Pun not intended.) When other nations try to imitate their know-how, the result is usually subpar.

In Israel almost all construction, even single family homes (not that there are many of them), has concrete/steel beams and floors as the load baring infrastructure, and light Ytong bricks serving mainly for insulation. But it's super common to remove brick walls, interior or exterior, to make changes to home layouts, and as long as you don't touch the beams it's safe.

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