Covid seems to be a big factor behind recent inflation in general . Business shut down or scaled back as people began staying home and demand decreased (along with the number of available workers). More recently, consumer demand has picked up, but supply chains remain disrupted. Low supply + increasing demand = higher prices.
As for lumber in particular, see:
https://www.npr.org/2021/07/08/1013819703/what-the-rise-and-fall-of-lumber-prices-tell-us-about-the-...
As for lumber in particular, see:
https://www.npr.org/2021/07/08/1013819703/what-the-rise-and-fall-of-lumber-prices-tell-us-about-the-...