I own three of thes sheds and am very pleased, till now.  I walked in my 10 year old shed after a rain storm and found water on my bench.  A vintage radio I was repairing was saturated with water, the wood case delaminating.  I looked up and saw a cracked sky light along the seam.  Checking further, I discovered all 6 ski lites were split on the full length of the joint on the side that gets more sunlight.