The solution to a deck with pine sap from dripping trees is Arm & Hammer Super Washing soda. Make up a very strong batch. Add 1-1/2 cups Super Washing Soda to I gallon hot water, apply and let stand for about 10 min. Then take a stiff scrub brush and go to work. It is rather efficient if the sap is from this season. If from last season, you will need a little more elbow grease. It will come off.
