I've been hunting for contractor quality cedar shims - the super-wide kind that easily break along the grain. The big box stores don't have them and neither do the local lumber yards. At one of them I visited, they told me that they haven't been able to get them since COVID started. What's the connection? What other materials might be affected by COVID going forward?
Like PhillipNagel said, the March/April red-alert for COVID caused a lot of production shutdown. Cedar shingles are not essential work. Shutdowns like this have largely stopped, even though recent numbers are spectacularly much worse (even in NYS). So the supply chain is working again.
However, demand went insane, on several prongs.
Cooped up at home: DIY home improvement!
Many blue governors and most tech companies have ordered "If you CAN work from home, you MUST work from home". With all that commute time back, people want to do home improvement projects. They're also just adding space to get a little privacy! A lot of these people have never done a home improvement project, so they think $8 2x4's are normal.
The building boom for people fleeing cities
In the last 20 years the trend was "New Urbanism": live in the urban core (or in dense-pack suburbs right on top of top-tier transit)... and have no car (or in a family, fewer cars). Partly for quality-of-life: see actual opera. See top acts at venues you can walk to. Have face-to-face gatherings of others into obscure interests (where a critical mass of fellows can only be had in big cities). 10,000 fantastic restaurants, and you couldn't even find the city's Applebee's, why would you need to? And partly for environmental conscience reasons - city living is more sustainable.
Now, everything that makes the city fun is closed. Proximity to your neighbors is scary. Public transit is radioactive. Further, giving up cars no longer has the environmental cachet it used to, since electric cars are happening for real now.
So there's a new rush for the suburbs and exurbs, and that's made demand for housing higher than ever. And of course, that's been soaking up the scarce building materials.
I for one think that trend will reverse once COVID passes. Which of course puts all the more pressure on homeowners to get their properties sold now - necessitating yet even more home improvement.
This has been a well-known issue since the pandemic started. Materials have been scarce, and prices have increased dramatically.
This seems to be due to issues on both the supply and the demand sides. Supply has decreased because of obvious issues related to COVID, workers being sick with COVID, factories having to shut down for periods of time, and working at limited capacity due to having to keep physical distance between staff.
Demand has also increased, it seems, because people are stuck at home, and are bored. Seems people either undertake remodeling projects due to being stuck at home and not having other "entertainment" options, and of course having to look at parts of their home they don't like much more know. There is probably also the component of the stimulus money being used on construction projects. Oh, and mortgage interest rates have been at historic lows for a long time, causing more demand on new construction.