Normal rainwater will not harm the wood that is used to build homes. Many homeowners fear that wood will immediately rot if allowed to get wet. That's simply not the case. The only thing that doesn't fare well if it gets wet is low-grade OSB.

Is it okay for wood to get wet?

Wood rot can and will start when the moisture content of the wood reaches 20 percent. ... The wood needs to remain damp and wet all the time for wood rot to advance. It's much more likely that you'll start to see mold growth in as little as 48 hours as mold spores are everywhere on your home construction site.

Can wood be damaged by rain?

Most species of wood don't do well when exposed to rain; exceptions include cedar, redwood, teak and ipe, which contain natural oils the safeguard them against moisture. Other species need the protection of a finish to protect them from rain and humidity, or else they quickly warp, crack and rot.