Hacker News Reader

Comment by brudgers | Hacker News Reader

Stainless steel rebar is uncommon for the same reasons galvanized rebar and epoxy coated rebar are not common.

As materials they are massively more expensive than carbon steel and first cost matters because public infrastructure is financed with bonds and financial markets dictate bond terms of 30-40 years.

To put it another way, any belief that construction markets are inefficient is statistically a dunning-kruger to too many sigmas. Construction goes back at least as far as anything we call as civilization.

View on HN

This isn't stainless rebar, it's stainless-coated rebar. Perhaps still to expensive to end up widely used, but it should be a lot cheaper than pure stainless.

Galvanized rebar and epoxy coated rebar have been available for many decades.

They are so much more expensive than ordinary carbon steel rebar to be unicorn poop rare.

If there is a break in the finish, it is as susceptible to corrosion as carbon steel. This means every step requires special handling and rigorous inspection. It cannot be field fabricated with a hand bender if a stirrup is missing or damaged. Tying and placement has to be done with unusual care to avoid damage (and again non-standard level of inspection).

Galvanizing and epoxy coating are long lead time and require prefabrication (bending). So you are shipping, handling and receiving bespoke space filling shapes instead of commodity straight bars to specialty job shops with limited capacity and well booked dance cards.

At every step, everyone has to price their work against all that complexity, uncertainty and potential for delays.

Galvanizing still works if there are scratches in the finish because there is a radius of protection from the galvanization.

Galvanized rebar is about 20% more expensive and is actually widely used in highway construction, particularly when salt is a major concern.

Epoxy coated rebar turned out to have much poorer efficacy than originally expected as you noted but the same is not true of galvanizing which is a much more durable coating.

Wasn't it found that epoxy-coated rebar actually doesn't help that much because it rubs off during construction?

What about for private construction?

You can get anything you are willing to pay for.

Talk to your architect…if I were still practicing and cost was no object, I would probably recommend epoxy coated and 6kpsi concrete and a specialty contractor [1]. I would not recommend someone’s theory over technologies with track records.

[1] And require a percentage of construction cost contract.

If you’re building a house: waterproof the structure correctly. This will protect most of your rebar, and it will protect your walls, your finishes, and keep mold from growing.

The lifespan of ordinary rebar in competently cast concrete that is kept dry is very, very long. Maybe if you live right next to the ocean you will have somewhat different considerations, but a quality waterproofing membrane on the outside of your foundation is worthwhile anyway and will help control salt spray as a side benefit.

If you visit, say, an 20 year old, incompetently built structure in a place with real weather (ski lodges are often like this), you can see that the concrete will be in perfectly fine condition, but the structure may smell moldy and interior finishes will be failing.

If you live near the ocean, usually chloride ion gets on the rebar during construction.

There is a big inefficiency in construction markets but it's not in materials, it's in labour. Immigration laws starve construction companies of workers. With unfettered immigration it would be much easier to build simply due to a large availability of unskilled labour. The other side of the coin is of course planning, zoning approval, codes, bylaws, and other regulations that slow down construction projects and discourage development.

We've made it very hard to build because we really don't want to build. Homeowners are mostly interested in protecting their investment which means keeping housing demand high.

it would be much easier to build simply due to a large availability of unskilled labour

Money makes construction easier. For example it facilitates hiring skilled labor (or pays for stainless steel rebar).

The US housing market is shaped by two facts.

1. Housing is just about the “lowest and worst” [1] way to realize returns on real-estate.

2. It is about as hard (and often harder) to build inexpensive housing as expensive housing.

[1] https://en.m.wikipedia.org/wiki/Highest_and_best_use

“With unfettered immigration...”

Or use well paid skilled labor and machines?

Construction sites need unskilled labour to haul things around, clean up the jobsite, hold heavy objects in place until they’re fastened, and the like. There aren’t any construction site robots that I know of which can replace all the jobs an untrained but otherwise strong and healthy human can do.

A strong trained human can do all the things you mention with less supervision and in less time.

In other words if there is a lot of work for untrained workers, it is a poorly run construction site. In a well run construction project, trained workers clean up after themselves and installers don’t need additional people holding up heavy objects during placement because they bring proper tools, staff, and falsework with them.

> With unfettered immigration it would be much easier to build simply due to a large availability of unskilled labour.

Isn't that ultimately an economic question - increase the supply and the cost drops, increasing the number of projects where the labor cost effective but driving down wages?

If the US did have much more immigration of unskilled contruction labor, but they unionized, keeping their wages higher, would that have the same result? That is, is your argument more than, effectively, exploiting labor?

Unionization only works if the union has the power to exclude replacement labour from the jobsite. “Exploiting” labour is a meaningless value judgement. There’s no scientific definition of what is exploitation and what isn’t.

Back in the late 19th / early 20th century we had no restrictions on immigration, minimal state welfare programs, and no minimum wage laws. Huge numbers of people migrated to the US for work, they rapidly built infrastructure and buildings in cities like New York and Chicago. There was high upward social mobility.

All the problems started with minimum wage laws and the welfare state. You can’t have a functioning welfare state with unrestricted immigration. When you restrict immigration you essentially create a black market for below-minimum wage labour. That’s why the US has such a huge number of illegal immigrants: to do the jobs that nobody else wants in construction and agriculture.

Before all this (effectively) regulation and restriction of the labour market, you had the ability for people to learn skilled trades on the job. That was a form of non-monetary compensation that is no longer economically viable due to minimum wage laws. Minimum wage laws set a floor on the amount of productivity a worker must supply before you can hire him.

The other problem we’ve caused with these laws is inflation. The cost of living has skyrocketed. People on minimum wage today are in many ways economically worse off than the migrant workers arriving in droves before minimum wage laws existed!

> “Exploiting” labour is a meaningless value judgement. There’s no scientific definition of what is exploitation and what isn’t.

Values are our goals, the most important things we have. The world certainly isn't limited to things with a scientific definition. (Also, I expect there are plenty of legal and related definitions of labor exploitation.)

> There was high upward social mobility.

You'll need to document some of these claims. Unions started because working conditions and pay were awful; people were widely exploited - including injured, cheated, etc. - due to their fundamentally weak marketplace position: the owner controls all the jobs, the worker only controls one.

Since unionization, the economy, pay, and working conditions have all boomed. It's hard to argue with the results - the greatest economic performance in history.

Yes, the wealthy and powerful don't get as much of the pie, but the pie is much larger.

> The other problem we’ve caused with these laws is inflation. The cost of living has skyrocketed. People on minimum wage today are in many ways economically worse off than the migrant workers arriving in droves before minimum wage laws existed!

That is a complete falsehood.

> unrestricted immigration

When and where has that happened? Who supports that? It's quite a strawperson.

Reply on news.ycombinator.com