DIY & Home Improvement

If someone wants to do the same but it will be exposed to weather, make the top similar to how a deck is built - put about a 16d nail's space between the boards. It gives room for expansion and contraction, and also rain drains through the gaps.

It is also much, much harder to seal properly, so you probably would need treated lumber. Age it in a dry place for at least 3 months, preferably a year, to make the wood workable....or just live with the warping.