Process improvement in manufacturing and construction: Duco vs. Drywall | Hacker News Reader

Process improvement in manufacturing and construction: Duco vs. Drywall

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41 pointsjseliger38 comments

I was disappointed that there wasn't a clear successor to drywall coming. I'm not a huge drywall fan, but not for only the listed reasons. I hate that it gives you limited-to-no options to easily maintain, repair, upgrade or retrofit new utilities. It means a very messy and time consuming "cut, do work, re-drywall, tape, mud, sand, paint" process that is way too onerous for a lived-in house. I've long wished for a new system that was both cheaper and more convenient for the long-term owner, but there aren't any that I know of that have gained any real wide traction.

As a DIYer that has done far too many drywall patches, as much as I dislike it, it's hard to imagine something easier and/or better. Most of the time, the vast majority of the work comes down to the painting part. The human eye is pretty darn good at noticing slight color differences and breaks in patterns, so any flat, smooth surface will show inconsistencies in paint color from the natural fading/discoloration of old vs new paint.

One could imagine a 'panel' system (like old school wood panels) that could be removed and replaced, but that would involve seams and fasteners that would need to be visible at all times. Even with wood panels or, let's say, plywood sheets, hidden fasteners would mean you're likely to damage the finish when removing it. Not to mention that it would require a regular pattern to (somewhat) conceal the seams of pieces.

Drywall, on the other hand, is almost a perfect compromise. It's extremely inexpensive, very fire resistant, and with some practice, it can be installed and/or patched with simple tools to make seams almost imperceivable. What it trades in durability and strength vs something like L&P, it more than makes up for in ease of repairs.

To add to that, painting wall in patches will always be visible under certain circumstances. That's because paint is essentially a film you apply to a wall. Any new film will be on top of new one and no matter how you try the border will be visible. So in order to hide the repaired area well you have to paint the whole wall from a corner to a corner.

And indeed there is no better general alternative for the drywall. If you replace it with any other solution like MDF, plywood, etc. the repair process will be still the same - paper, mud, paint. But the material will cost you much more. And those materials are harder to cut, you'll definitely need to use a saw instead of a knife.

Maybe I watch too much science fiction, but I can easily imagine a grid of plastic or aluminum panels which you could snap off when you wanted to work in the wall, and snap back on when finished. I don’t have a feel for if it could be done economically. It would certainly be a way different look from what we are used to.

There were briefly prefab houses built exactly this way.

https://en.m.wikipedia.org/wiki/Lustron_house

> that would involve seams and fasteners that would need to be visible at all times

Probably I have an unconventional taste but I would not mind visible fasteners at all (if they look neat i. e. not at irregular intervals/angles/depth). Moreover I perceive what would be considered an ideal drywall (flat, smooth surface) to be an imitation of brick/stone wall covered by plaster, like jewellery made from plastic with 'gold' paint - looks similar to gold but at closer look you can see that it is not the one.

I very much hate dealing with drywall. Here are the things I use that help:

20" box fan with a decent air filter https://www.lasko.com/products/air-flex-air-purifier-and-roo...

Rigid shop vac https://www.ridgid.com/us/en/12-gallon-nxt-wet-dry-vac

Accompanying air filter kit https://www.ridgid.com/us/en/osha-filtration

Rotozip drywall bits https://www.rotozip.com/en_US/web/rotozip/tool-detail/-/roto...

I use a Milwaukee rotary tool with the Rotozip bits, but a lot of brands make equivalent power tools that are all essentially the same. The rotary tool embodies a big reason why I dislike drywall - the dust. The rotary tool fills the air with an incredible amount of dust, so I only ever use it with the Rigid vacuum in the other hand as close as possible to the cut. It is also loud and hard to control, but the advantage is unparalleled safety while cutting into the wall. It won't nick wires, and it won't cut into wood studs. When trying to cut along the edge of a stud, the rotary tool is how I start each cut.

I'm also working out a pretty good technique for running wire through notched wall studs behind drywall. I haven't tested it fully, but it basically combines both of these techniques:

https://youtu.be/Z2xR5YnIfGA

https://youtu.be/EXhDlDBzXjY

The rototool is nice but for a lot of drywall cuts I just use a drywall saw - it’s slower and doesn’t dust as much.

Agreed about regular drywall saws! Just doing it by hand seems to give the best results. Fancy tools help with ancillary things.

Same here, plus I use an oscillating tool for things like square holes for outlets. And a hole saw for round holes.

I tried a rotozip once but never again, they are just too loud and messy.

I was helping a professional drywaller and he used the rotozip for only one thing - cutting out boxes after throwing the drywall over them. Everything else was knife (preferred) or saw.

Shiplap is the only thing I’ve found and even that isn’t cheaper. Maybe wood panels but those look so 70s.

The real deal is to learn how to mud and sand well and then never patch a hole - just cut it back to the studs and redrywall.

As a homeowner building drywall skills is super important and money saving skill. With some basic tools you can easily build super high quality surfaces if you learn how to mud and sand. Drywall is an amazingly maintainable product - my guess is that most homes out there have all kinds of drywall patches applied that behind the walls would look like a horror show but to the casual eye is flawless.

The finish level is housing almost always implies using some product that is mixed with water for the finish level: drywall mud, cement, thinset, etc. The maintainability of these surfaces is key. It certainly is a natural maxima: cheap and easily workable. Even if the wall surface is really bad you can easily apply a skim coat and your wall looks new. What the article didn't touch on is that there certainly is room here for automation at scale: the process of installing many panels, taping, mudding, etc does require skill. There are videos out there of robots doing this work but not sure if it competes with a crew of skilled workers.

I don't find the finish on cars to have this same kind of maintainability. Fixing / matching paint on a car is hard for me.

+1 to that.

My parents had a sliding glass door put in their bedroom and they chose to have the opening unfinished for some reason. I happened to come by and got to show them how to match up the edges because the original home builders were apparently opposed to having straight walls, took like 20 minutes and saved them some money.

Learned this stuff when I was living with my father as a teenager and he was doing general construction projects (badly).

Skill is only required if you want to do work for pay in an economically viable manner.

A homeowner, or anyone working on a small scope project can just have nearly no skill and throw tons of time at the problem to compensate. This applies to a lot of things in life.

The walls of my parent's house are plaster, and it's impossible to find anyone who can repair them. OTOH their walls are completely smooth, which is aesthetically pleasing.

When we build our house they had an option for "smooth" instead of textured walls (which they spray on). The smooth option was about 10k more, because of the finishing work required. Go figure.

Plaster is almost unheard of where I'm from (Nordic country) but here in the UK it's basically everywhere. Old-school plaster is the default option here, even more so than plasterboard. Lots and lots of tradesmen who specialise in it (and it takes a bit of skill to do a good job).

I'm still not sure what I think of it. On one hand, it looks beautiful and has a nice texture, but it just always, always cracks, sooner or later.

In the UK, almost all homes are constructed with bricks - so you can plaster directly onto the bricks, with no need to put up laths like you would for American-style timber-framed homes.

Ceilings are usually plasterboard in most modern homes in the UK, rather than the lath-and-plaster used in older buildings, ain't nobody got time for that :)

Also not to forget it's very common to have a thin coat of plaster on top of any drywall.

To be honest, I'm not sure why we do this, but it makes for a far more durable finish than just drywall.

I hate plasterers, they are the messiest trade, plaster splatters and dust everywhere. If you can avoid ever having to use a plasterer, do!

> impossible to find anyone who can repair them

Still a few people out there, e.g. US trade association dedicated to the craft of plaster and drywall, https://news.ycombinator.com/item?id=32991963 plus some books, https://www.wconline.com/products/547-plaster-and-drywall-as... & https://icontractor.net/products/plastering-skills

I'd honestly rather have smooth walls. I have textured walls now, and apparently there's 20 types of texture everyone does differently. So I'd have to basically find the guy who did it 20 years ago and hope he even remembers.

I've not been able to find a painter to exact match my texture. Close? Definitely. But I still stare at it at times, it nagging at me with its subtle differences.

The only issue is the smooth surfaces eventually develop imperfections from humidity changes or as the structure naturally settles. Textures help with that quite a bit

I see in this article no mention of a simpler interior wall material: brick (also used for exterior walls). At least where I live (southeastern Brazil), I don't recall seeing drywall or similar outside of office buildings; every house or residential building I've seen uses brick (covered with mortar and painted) for both internal and external walls.

That's interesting. Are these walls insulated? Brick is a very durable finish, but it has certain disadvantages. It is labour intensive to lay. It requires more planning for passing electical and plumbing conduits. It also can have unfavourable energy efficiency characteristsics - the high thermal mass retains heat if in the sun, and then bakes the house at night.

> Are these walls insulated?

As far as I know, no. But the brick most used here is a lightweight perforated brick (a quick web search found a site with some pictures: https://portalvidalivre.com/articles/949), and I believe the air trapped within it does have some insulating properties.

> It requires more planning for passing electical and plumbing conduits.

Not as much as you'd think. The way I've seen it done is: first you put the bricks as normal, then you dig a trench in it for the conduit, put the conduit, and fill the rest of the hole with brick fragments and mortar.

In the Eastern US there are a lot of brick homes with drywall interiors. In my home there some walls with only a few centimeters between the brick and the drywall and in other places there is a full stud between the brick and the drywall. Even though this is not required (i.e. many offices are all sinter block or brick), this allows for easy finish electrical and the rest of the US building industry to be easily integrated into the building.

For another contrasting example, I have a friend that moved to Germany and found out, like many Americans that have moved there, that you need a totally different skillset to install things into the wall. It's very common in Berlin to live in apartments where the walls are made of concrete. I helped her install a few light fixtures on a visit and boy did I wish I was dealing with mudded brick or drywall.

Are homes there air conditioned? Is humidity a factor? Drywall basically requires air conditioning in humid places, brick does not. Lots of places around the world use cement construction blocks (aka cinder blocks) for all walls, interior and exterior due to durability and hurricane resistance.

> Are homes there air conditioned?

Air conditioning is becoming more and more common, but the same kind of brick wall with mortar was already used back when ceiling fans were the most common cooling mechanism.

There are two factors that come into play with the plaster/render vs drywall choice:

1. Labour vs material cost, increasingly it's cheaper to drywall rather than render/plaster a wall. It's quicker, therefore if Labour is expensive, it works out cheaper. When you also look at running services the gap behind the drywall is useful and saves masses of time.

2. Insulation, both thermal and sound. The small air gap behind the drywall forms an additional layer of insulation.

> Plaster would be pushed through the gaps, which would act as keyways, holding the plaster in place (later things like wallboard and steel mesh would be used as backing material).

I lived in a condo that used steel mesh for backing material. The WiFi signal could barely make it through a single wall of that place.

Well you're protected from solar flares at least.

> the first, heavy coating of plaster (called the “scratch”)

though most web results for the etymological origin for 'made from scratch' point to 'scratch' being the starting line of a footrace

The scratch coat of plaster made in stucco has horizontal scratches in it made with a scarifier (looks like a hand held metal rake). This is a rough coat that the brown coat (next layer) can attach to.

This doesn't refer to "made from scratch" interestingly.

... where "made from scratch" refers to the rough grains and cracked corn intended for chickens. If you further processed the chicken feed (scratch) you could make corn bread and what not for less money than people food

Actually it refers to the scratch line of a foot race, the starting line. Some racers were allowed to start a little ahead as a handicap. So starting from scratch meant that you started at the beginning.

Made from scratch came along later, picking up from the usage of this word.

What I'd like to know is where "Old Scratch", aka the devil came from.

Interesting, I had heard the "chicken scratch" explanation pre-internet and assumed it was so. But looking now "primary starting line" makes better sense

This is a fun one for me, as I've worked in an auto manufacturing paint shop and I've done drywall.

They have something else common that the author didn't mention - imperfections.

I worked on custom homes with my dad growing up, and some customers demanded "triple perfect" work. Any wall can look smooth with lights pointed straight at it, or with diffuse lighting. Most walls look really bumpy when you shine a light down the wall. During construction, you are working with natural light. The customer sees the home after overhead lights are installed and after blinds and shutters are put in. This completely changes which imperfections are visible. Small scratches become pronounced; changes in texture show up. Customers can see ALL of your work. Who knows if the electrician has some half-tight wire nuts? But we all know when the drywall is bad.

Another thing drywall and automotive paint have in common: Repairs have a 50/50 chance of making things better. Automotive paint repair in this case being during the OEM process, not a collision repair. Collision repairs have a 0% chance of looking exactly like OEM paint.

Small imperfections may be fixed or covered up, but you have to skip back several steps in the process.

For drywall, if you are fixing scratches, you just have to disrupt part of the texture and paint. If you are fixing a lumpy butt joint (seam), then you have to disrupt a large area of texture and paint. The repaired texture may not match - air flow in the texture gun, humidity, exact proportions of the texture mix, temperature - will all be different. Paint has a different pore structure and dries differently on texture vs paint. This often affects the specular look of the paint.

For automotive paint, much of the same applies. Humidity, paint mix, metallic or mica mix, temperature all play a role. As well, for a repair, you are not painting primer, you are painting paint. It's very hard to match edges, so often whole body panels or even the whole vehicle is repainted. For the paint process I'm familiar with, you only get 2 tries to fix any large problems - the vehicle has to go through the oven again for each repair, and too many passes puts you out of compliance for the paint and adhesives.

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Anyway, how to replace drywall? I don't see it happening on a large scale. I think drywall can definitely be improved, but even for most of the replacements listed drywall will be installed under the product listed. For instance, MDF does not meet fire code. Anything that uses adhesives instead of screws is MUCH harder to repair.

Some things to ponder for replacements:

- Fire code

- Speed of install

- Look and feel

- Ease of repair ( you may not like drywall repair costs, but they're nothing compared to other products)

- Ease of demolition

- Toxicity/outgassing

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