How much space is between each slat on the Birch Foundation? December 12, 2022 17:02 Updated The Birch Foundation includes 12 slats that are ¾ thick with approximately 5 inches between each slat. Related articles Why is the Birch Foundation the perfect fit for my setup? What are the dimensions of the Birch Foundation? How is the Birch Foundation assembled? What is the weight limit on the Birch Foundation? What is the Birch Foundation made from?