I AM IN THE PROCESS OF BUILDING AN ARBOR OVER MY PATIO. IUSED BOTH TREATED AND NATURAL PINE. I HAVE BASIC WOODWORKING KNOWLEDGE AND WENT WITH THE ADVICE FROM THE DUDE AT HOME DEPOT TO SAVE MONEY BY USING UNTREATED LUMBER. WHAT IS THE BEST WAY TO WEATHERPROOF/SEAL THE WOOD.ALSO ANY TIPS ON FIGURING RAFTER RIDGE LENGH ON A 14X16.8-12 PITCH.