The article says you should have 1 downspout for every 600-800 sf of roof. What determines the proper size of the gutters & downspouts? Won't a four inch carry at least 25% more water away than the three inch? Should I use a 5"?
Links:
[1] http://www.moneypit.com/article/basement-waterproofing-leak-prevention-and-useful-tips