The wonder of modern drywall

A huge share of the gypsum used in drywall is *synthetic gypsum* — a byproduct of flue-gas desulfurization (FGD) at coal-fired power plants. When SO₂ is scrubbed from exhaust using limestone, the reaction produces calcium sulfate dihydrate, chemically identical to mined gypsum. In the US, FGD gypsum has accounted for roughly half of all gypsum consumed by the wallboard industry at its peak.

The "cheap, uniform, and free of defects" story is partly a story about coal. The drywall industry scaled on the back of an abundant, nearly free waste stream from the energy sector. It's a classic example of industrial symbiosis — one industry's pollution abatement becomes another's feedstock.

And it cuts the other way now: as coal plants shut down across Europe and North America, synthetic gypsum supply is shrinking. The drywall industry is facing a real raw material squeeze, with manufacturers having to shift back toward mined gypsum or find alternative sources. There's ongoing work on using phosphogypsum (from fertilizer production) but that comes with its own radioactivity concerns.

For someone in your position this is particularly relevant — the "wonder" of drywall is entangled with the fossil fuel economy in a way that makes earth-based construction methods look increasingly attractive as that supply chain unwinds.

As a German I always found North American houses and their drywall and wood constructions incredibly odd. It always felt flimsy to me. From my experience we just started using drywall for some interior walls on some newly built homes. But throughout my life I was used to very massive walls.

I recently saw some house building videos and it is somehow fascinating how different the building materials and methodologies are. North America obviously made it work, but still very odd to me.

Picture rails are a kitschy and twee feature that few people today even know their purpose, but anyone who tells you that they’re just as good for hanging things on are committing perjury

In my humble opinion, they are significantly better than pounding a nail into drywall. Of course, I also have an absurdly large collection of framed photographs and other art, all of varying sizes, and I love swapping frames around throughout my home. Having picture rails throughout my house means I don't have to keep pounding holes in the wall every time I replace that 20x20" photograph of my toddler shot in a square aspect ratio with a 16x20 shot on my 4x5, or whatever.

But the noise.. this has been a huge factor in my quality of life, having lived in both buildings. That issue trumps any advantage drywall has, and I spent about 10 years working with it as well.

I think the market forces have simply dominated our natural, economically inefficient, home-dwelling instincts. I think this article means well, but it is written from the perspective of a landlord basically.

> Because drywall is a dense and uniform mixture, hanging anything off the wall (from pictures to heavier items like shelves, TVs, or even cabinetry) is a trivial exercise, either a simple nail for a small frame, plaster anchors for medium loads, or toggle bolts for the real heavy hitters.

yikes

Works In Progress have an odd antipathy to picture rails. Actually, picture rails are good. You don't have to fill any holes if you wish to move or remove a picture. To put up a picture rail, you can drill multiple holes laterally until you find a stud. The unused holes will be covered by the rail.

Interesting to me that no mention of the use of drywall (in various forms) to act as a substrate for actual plaster. This seems common in the UK from what I understand from my family back there, and it is also common in the USA in high end residential construction. It is particular common in Santa Fe where I live now (for high end anyway) because the so-called "diamond plaster" look & feel is very popular. So, you still build with stick frames (or in a few cases, cinder block), cover that with drywall/sheetrock, then plaster it.

Drywall is pretty amazing, but I don't agree with all the points in the article.

It cheap to buy and cheap to install, easy to cut and installs fast. It's tolerant with imperfect walls and is surprisingly flexible. It can also be seamlessly repaired.

It can also act as a primary air barrier.

I do not like moisture resistant drywall, moisture control is more important as well as using proper materials in high humidity areas.

I really like this guy's drywall-install how-to videos: https://www.youtube.com/@vancouvercarpenter

If I ever get to build a house I’m using that high density drywall they have in hospitals everywhere but the ceiling. It doesn’t cost that much more compared to the labor and it would be enormously satisfying to know your walls can’t be easily dented or damaged.

I am also a fortunate owner of a 100+ year old home. Why is the lath and plaster so susceptible to cracking?! That is my nemesis. I haven’t tried to hang a TV though yet.

> It’s impossible to mount even lightweight items such as picture frames onto the wall, because even the tiniest hole from nails or the like would crumble and erode into dust.

The trick for this is to just find the stud. Same thing you'd have to do in drywall. For light stuff like photos, you can get away with putting a nail right into the lathe without having to find a stud. If you miss the lathe (you can tell) just move the nail up a half inch.

Drywall is terrible vs. modern plaster.

Modern plaster has backing boards that are similar to drywall, so you get most of the construction advantages (except for the labor intensive step of plastering), and can hand pictures / toggle bolts in the same way. Unlike plaster, drywall gets moldy + needs to be replaced after water damage. I think this is why films with old buildings set in Europe often show peeling paint / water damaged plaster, but people are still living in them, and it seems fine. In the US, buildings with that level of wear would be so moldy they'd need to be gutted to studs, at minimum.

The article touches on mold resistant drywall, but I'll believe it when I see it. Also, apparently, it is much easier to create long-lasting patches for plaster than drywall.

1. Is plaster and lath gypsum based? In my experience plaster is basically identical to stucco, which is basically just mortar with increasingly fine sand. It is very hard and completely unlike drywall.

2) Why emphasize asbestos when talking about plaster? My understanding is you likely have more to worry about if you have a house from say the 40s-70s, which almost universally have some sort of drywall product.

I think this misses the beauty of a plaster wall. Level 5 drywall has nothing on a skilled artisan with plaster, and yeah you can’t hang things through it but it also lasts hundreds of years. My walls are 120 years old and robust, the kids haven’t damaged them and they’ve more than held up.

I stayed with a guy in France who had an old house with these picture rail things, and it was the first time I had come across something like that. I thought it was a very interesting solution for quickly rearranging artwork in your home if you love art but don't have enough wall space to display all your pieces so you might occasionally swap them.

I will never understand why we fill our walls with mechanical and electrical infrastructure and then wrap them in a paper and plaster, which then needs to be torn, broken, and repaired in order to maintain said infrastructure.

Pipes will fail. Wires will fail. Ducts will fail. Maybe not in 5 years, but over the span of 20, they will. Why make them so frustratingly inaccessible?

“You’re in luck if you’ve been hankering to have your wall connected to wifi.”

There are reasons not to like gypsum drywall:

> Some buildings standing today still have wattle-and-daub panels from 700 years ago.

Will any drywalled building survive even a tenth of this time?

> The plaster mixture used then was a homegrown concoction, with recipes matching the climate needs and vernacular material availability.

The wonder of wattle-and-daub (clay) and plaster-and-lath (lime) is that the materials are breathable, move with the structure, and can even self-repair small cracks. I don't know of any old house that suffers from black mold...

My last big gripe with gypsum drywall is disposal. Demolish a property with clay or lime walls, and they'll naturally degrade into the environment. Drywall needs proper disposal: "Do not burn: Drywall releases toxic fumes. Do not bury: It can create dangerous hydrogen sulfide gas in landfill."

Does anyone want to live with that?

some interesting new failure modes also: https://en.wikipedia.org/wiki/Chinese_drywall

Ctrl F "brick". Nothing about bricks and concrete in all the history of wall surfaces.