Baluster Layout?

[Paul Dombroski]

What's your formula for laying out balusters on a straight run? Balusters are 1" wide and the span between newels are approx. 72". There are to be about 16-17 balusters in each section.
Thanks
Paul

[Mike Jones NM]

You might want to lay this out and play with it because it has been more then a few years since I messed with it but I come up with the following
If your going with 17 the distance apart will be 3 1/4" if your using 16 the it will be 3 1/2"

[joe greiner]

Conceptually, add one baluster at the end of the run; 72" + 1" = 73".

Minimum gap should be 4 inches to satisfy building code. Maximum pitch is then 4" + 1" = 5".

Minimum number of pitches is 73"/5" = 14.6 -> 15.

73/15 = 4.8667"; -1" = 3.8667" gap. An awkward dimension.

73/16 = 4.5625"; -1" = 3.5625" = 3 9/16" gap. Good for 15 balusters.

73/17 = 4.2941"; -1" = 3.2941" gap. Awkward again.

73/18 = 4.0556"; -1" = 3.0556" gap. Very close to 3 1/16" for 17 balusters, but sums to 73 1/8". Make end gaps 3" to divide error equally.

Joe

[Neil Bosdet]

Mathmatically: You need 4" for gap and 1" for each baluster. To get the measurement you knock off 4" for the end gap and then divide by 5.

72-5=67 67/5=13.4 (round this up to the even number = 14 balusters needed for this span)

So now you work the other way. Take your span, deduct your balusters and divide the remaining number by the total spaces (balusters +1) =15

72-14 (balusters)=58 58/15 (gaps)=3.867

This is your spacing between balusters. It's close to 3 7/8", so I'd space the first and last gap by the difference and use 3 7/8" for all the others. (The first and last will be 3.8125" or 3 13/16")

Using a tape measure and a square you can do this another way. I saw it in Fine Homebuilding (I think). Mark a square line (90) from one end of your run. Start a tape measure from the other end to the your end with the square line. If your spacing doesn't work out perfectly for your balusters and 4" gaps, angle your tape measure out from end with your square line until a uniform gap number hits the line. Hold the tape measure in place and using the square, run along your railing line and mark each baluster as the square crosses the appropriate spot on your measuring tape. This is a cleaver solution to head-scratching math.
I hope this makes sense. It is quite visual. To mark the leading edge of each baluster you'd run your square across the edge and mark off at 4", 9" ,14" ,19", etc. until you finish your run.

[joe greiner]

Neil's second method is a full-scale version of a technique used by paper-and-pencil draftsmen to divide a line into equal parts, e.g. for a stair layout. With CAD, of course, it's now a one-button command. The advantage of this method is that you don't accumulate measurement errors by measuring point-to-point.

The mathematical method can be combined with the one-shot measurement with a spreadsheet or a calculator. Arrange the arithmetic to produce subtotals of the baluster edges from a common base point. That point is the anchor for your measuring tape, and you mark the locations from the subtotals. The technique is called "true positioning," and also avoids cumulative errors. It's generally more suitable when the point-to-point dimensions are unequal.

Joe