I'm taking an online woodworking course (The Weekend Woodworker), and built a small patio table a few months ago. I made it out of select pine (kiln dried), spray painted it (~2 coats), and put in on my back deck. Being the first thing I've ever made, I was (and still am) pretty proud of my efforts! However, I noticed today that the top of the table is already cracking:
What could be causing this? The deck is south facing, and gets a ton of sunshine all day, so perhaps it's a UV thing? I also note that water sits on top of the table after it rains, as if the top boards are cupped a little (I did indeed sand the top). I try to dump the water off each time this happens, but I'd like to know what (if anything) I did wrong.