For exterior use, the design of your bottom railing is critical! Normal flat-topped bottom railing (shoe) will NOT shed water properly. Worse, bottom rails with a channel (meant to receive interior Balusters) actually trap water! Also, interior bottom rail styles appear very lightweight when used outside.
Our Sloped-top Bottom Rail solves these problems! Two interlocking pieces provide easy installation, hidden hardware, and substantial, traditional styling! Just screw top piece of Railing into bottom of notched balusters. Then, using our pre-drilled holes, screw bottom piece of Railing into place.
Calculator assumes use of Large Sloped-top Bottom Rail when you specify 3-1/2" wide Balusters.