At 18′, this $150 piece of cedar (that had to be special ordered via Home Depot) is the longest single piece of our house. “Crowning” is a new concept for me, which means making a conscious choice about which side of the piece of wood will face up (well, it will face up once the wall has been put in an upright position). Since wood is organic matter each piece is a bit of a special snowflake. It is supposed to make the house stronger in the long run if the “rounded” side of the wood is facing up.
Although the beam looks very bent at first, once it’s actually screwed into place it takes the right shape: