The beloved backyard deck, in historical terms, is a pretty new element in houses coming into vogue some some forty or some years ago. What’s more, decks are the only structure we build on the outside of the house that must endure what’s called “wet service,” i.e. rain, snow, sunlight, drying, and so on. Yet, when it comes to popular DIY projects, my experience is that there is hardly one more desirable than building a deck — nor as potentially dangerous. While many DIY’ers I’ve met think it takes just a few weekends (pros and veteran EHT’ers know better) to slap a deck together, it’s more complicated than that.