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Divide the length of the run by the spacing. Add 1 if you need an ending baluster. Add more if you are planning for waste.
Or is this a trick question I'm just not seeing?
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ParadigmProjects.com | Paradigm-360.com | Mac4Construction.com
Yeah. It's E = mc squared
Seriously, there's no formula I know of, but you can do the math. Sit down, relax, get a calculator, some paper and a pencil, and let's go to work.
You will need the horizontal run ("L") of space between end posts, and the width or diameter (at the thinnest point), of your balusters ("B").
Solve this equation to get the number of baluster spaces, excepting the spaces between end balusters and posts:
N = (L - 8 - B) / (4 + B)
Let's try it for a 120" run and 1" balusters. I got N = 22.2 So should you.
You've now got to round N up to the next higher full number, or in this case 23.
So, post to post, we'll have an end space, then N+1 (or 24) balusters with spaces between each, then a final end space.
Our total run, L, will have 24 balusters and 25 equal spaces.
The balusters will take up a total of 24 times B, or in the example, 24 inches.
Each space will equal L, minus the baluster packout of 24 inches, divided by 25.
Calculate this and you get (120 - 24) / 25 = 3.84 inches.
There ya go!
It may sound complicated, but hey, it's stairbuilding carpentry. Whaddya gonna do?
Gene,I use your formula except for one little thing.My formula is:
N = (L - 4)/(4 + B)By subtracting your spacing twice (8 instead of 4) and subtracting the baluster diameter you've just added an extra unit (baluster width + spacing). If you omit this step the answer will always be the same.
Jon Blakemore
(disqualifier: dyi-er - never done this before)If you've got a moment here's what I've got:69" for L & 2" for B(69-8-2) / (4+2) = 9.83 round to 10N+1 =11 BWould that give me 12 spaces
(69- 22) / 12 = 3.91Okay how to convert 0.91 to a fraction on a tape.Thanks
count the number of spaces between pickets...
divide that into the length...
that is yur OC spacing..
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Her is what I use that is a little easier to use for a lot of people who haven`t taken math for awhile.
Take your measurement say 47.5 inches and add the width of one baluster. Often times it`s 1.5 inches. That gives you 49 inches.
Divide that by the spaceing you want (4 inches + baluster width of 1.5 =5.5) 49 divided by 5.5 = 8.90
You can`t have 8.9 spaces so round it up or down to the closest whole number in this case 9.
Divide 49 by 9 = 5.44 inches. Multiply .44 times 16 which gives you 7.1 Forget about the .1 It`s too small to be noticed. your spacing is 5 7/16. If you measure from the left, the outside edge of your first baluster will be at 5 7/16 inches.
It`s easier to show it in person I hope my written explanation can help.
>>snipIf you measure from the left, the outside edge of your first baluster will be at 5 7/16 inches.snip<<So, I have 2- 4x4s as posts (69" apart )- from the inside edge (left) to the "left" edge of the 1st baluster is 5-7/16"? Then, do I pull from the left edge or but to the right edge?Post| <- 5&7/16th -> B <- 5& 7/16 -> B <- B 5& 7/16 -> B ...(??)
I should have used your measurement when I was explaining my method. I was using an arbitrary measurement.
69+ the width of your baluster say 1.5 69+1.5=70.5
70.5 divided 5.5 = 12.81 (4 in + 1.5 of your baluster gives you 5.5)
Round up 12.81 up to the next whole number 13
70.5 divided by 13 = 5.42
Multiply .42 by 16 to get 16ths .42 times 16 = 6.72 sixteenths
or if you want 32nds .42 times 32 = 13.44 thirtyseconds
Let`s use 32nds From the left newel I measure 5 13/32 and that represents the outside edge of my first baluster. Then I cut a block at 5 13/32 and use that to lay out the rest. Gene is right that you could have some cumulative error but if this is for a fence or deck it won`t be much. If this is a fine woodworking stair baluster you may want to check out Gene`s method which I will do when I have time. But this method is fast and easy once you get the hang of it.
Edited 3/5/2005 5:41 am ET by MCCARTY12
I went back and read the whole thread and saw that you were using 2in. pickets. I thought you were probably using 2 by 2`s which are actually 1.5 in. If you are using actual 2 in. pickets you will have to rework the numbers but it comes to 5.91 in.
Sorry about the confusion
Thanks.As you mentioned, I'm not building a piano.You were right, I measure the sticks and they were 1.5" not 2. Should have figured. (really its a great scam how they get away with that whole issue a 6x8 is really 5.5 x 7.5)
When you say "outside edge" you mean the "far" edge of the B? I don't know how to say this, but will try. With the B, the 1st edge would be "inside" and then the 1.5" of B material, then the "outside" edge?
Since you have balusters that measure 1.5 in. you have to use the calculations from post 35.
The space from the post to the first baluster is 3.92 in. the baluster is 1.5 in. and the outside edge of the baluster is at 5.42 in.
Explaining in writing is not so easy sometimes so here goes one more time. From the post to the inside edge of the baluster is 3.92 in. From the post to the outside edge of the baluster is 5.42.
Edited 3/6/2005 6:06 am ET by MCCARTY12
Got it. Thanks.Really, thanks for all the help.
I'm getting 4 & 1/16 on a 43 & 1/2 post to post. Am I doing something wrong?43.5 + 1.5 / 5.5 = 8.1344.75 / 8 = 5.59.59 * 32 = 19 /32 I rounded to 18/32 or 9/165 & 9/16 - 1.5 for B is 4 & 1/16 over my limit.
Always round up to insure you say under the code of 4 in.
43.5 =1.5 =45
45 divided by 5.5 = 8.18
Round UP to 9
45 divided by 9 = 5
Feel free to ask any questions and good luck.
Thanks. I just thought rounding to 9 would make it look to close together compared to the other "runs."
I understand. The only way to make it close to the other runs would be to lengthen the space between the posts which is probably not feasible now. If you wanted perfectly spaced balusters you would have had to plan your posts accordingly in the design.
I wouldn`t worry about it. But just think how great your next balustrade will look.
Thanks. I just decided not to build a piano. It looks fine, for my untrained eye. I've got apx 20 days till the permit expires.What I did find, btw, was my friend who built or framed the posts and installed the rails, didn't plumb them. Oh well.Again, thanks.
I keep this in my head about decimal inches, among other things. Thirty-one thousandths (0.031) is about a 32nd.
So you are about 3/32 short of 4" for your spacing. It is 3-29/32"
Multiply .91 times 16 =14.56 That`s 14.56 sixteenths. I`d just round it up to 15/16 unless I was building a piano.
I would never lay out a balustrade by using the space between pickets. For me, that space says whether I meet code or not, only.
If there are holes to be drilled, I want to know where the centerlines are. If we are socketing into a plowed rail with a square or rectangular section, I want to know where each leading edge goes.
So I take the time to figure where these tick marks go, on a tape set up "hooked on" one end, somehow.
This eliminates cumulative error, like the kind you can get by having fat pickets, or rounding up or down to the nearest 16th.
I was able to download a free program that does all this from the Gary Katz site. Loaded into my Palm Pilot, it asks this, in sequence:
Total run
Baluster size
Desired common space (that is your 4") maximum
Starter and finish spaces (in case you want to be, say, 2" off each newel, but 4" between, elsewhere)
Punch in the data, then compute, and you'll get the spacing, in fractional inches, to the nearest 32nd. But, as I said, that's just FYI.
Punch "layout" repeatedly, and you get the position, from zero, of each successive newel's center, 1, 2, 3, . . . n.
Now, we're talking.
Thanks for the tip and a new way of doing something. I don`t have a Palm pilot yet. I`ve been a little slow buying technology gadgets but I`m coming along. I was in the first wave of cell phone users though. I had to start to lift weights to get the strength to carry the phone around!
gene.. i can get any layout i want... my question is this..
i hate balusters against the newel.. i always want to start and end my run with a space.. not a baluster..
i know it is fairly common practise with a lot of rail systems to begin and end with a baluster, just so they cn nail the balusters to the newel to support the rail..
but this is NOT the way i lay out..
so... here's the question.. this is an aesthetic question....
is the first and last space the same as all the other spaces?
ie: do you treat the newel as just another baluster?
or do you reduce the space by 1/2 the thickness of a blauster
i think that someone like kevin with formal training may know the answer right off the top of their head..
i've seen discussion on "intercolumniation " whcih may or may not pertain to baluster spacingMike Smith Rhode Island : Design / Build / Repair / Restore
Mike,I'm not Gene or Kevin and I certainly don't have their wisdom but I agree with you that there should be a space between newel and balusters and I think it should be a full space.
Jon Blakemore
My formula up in one of the early posts on this thread, presumes that you want that "starter" and "finish" space to be the same as all the "between picket" spaces, and that you want it to be under 4 inches.
If my newel has plumb sides, I stick with the "starter = between = finish" design. The few that I've done with box newels, were done that way, and looked OK to me.
The nice thing about the little Katz download that works on the PDA is that you can set your "starter" to be something different, if you want.
Here is a situation where you might use the Katz algorithm.
The one I did last year (see attached pic) has tapered newels, and 3-1/2" pickets, and because of the amount of newel taper, I fudged in my start and finish space, to look OK to the eye, both at top and bottom. Sort of a Goldilocks and the porridge approach . . . not too wide at the top, not too crowded at the base.
You can't see the result in the pic, but you can get a sense of how much the pyramidal newels are tapering.
gene.. i really like that newel...
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Mike Smith Rhode Island : Design / Build / Repair / Restore
Edited 3/4/2005 6:31 pm ET by Mike Smith
Didja look close and see the little keyhole detail in every other picket?
Newels and pickets were all detailed, right on the drawings, by someone in your neighborhood, Dick Estes.
uh... that would be jim estes..
and yes .. i did see the keyholeMike Smith Rhode Island : Design / Build / Repair / Restore
Thanks for all the replies. I'll be working on it this weekend.
yep .. it's only an example.
hope nobody tkes it as gospel...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
You could also use a stick laid out to comply with code. Say 4” + the thickness of one baluster. Mark the rail length on a sheet of plywood from right to left. Lay the layout stick down on a sheet of ply with the thickness of one baluster burned/held past the mark to the left and take notice of the first mark past the edge of the ply at your right (length of the rails + one baluster). Swing that end up to meet the edge of the ply with the first longer layout mark. Transfer the layouts to the ply on the angle and square them down to the edge of the ply where you pulled the rail length. This will layout the rail equally, out-to-in, on center, and give you spaces less than 4”.
here's how i usually be doin baluster spacing
4.5" space is .5" over the limit...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
joe.. i use the same thing..
the "imaginary " baluster buried in the edge of the newel
but i think .... maybe even better..... the CENTER of the "imaginary " baluster buried in the edge of the newel..
the result is a reduction of the first and last space by half the thickness of the baluster
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Mike Smith Rhode Island : Design / Build / Repair / Restore
Edited 3/5/2005 8:24 am ET by Mike Smith
I built that balustrade in your house last year. those balusters were laid out by me using the time honored method of dividing the space with a simple set of dividers. The reams of computer generated information that you gave me did not work out as you thought it might. It is one thing to toy with these things in the abstract, and quite another to actually make a good living building them in the field.
The space between the newel and first baluster will look different even iffen it is the same since the newel often tapers more. So I think you can eyeball it to see what looks good. A related thought, Have you tried pairs or even trios of close set balusters (baluster/1-1/2" space/baluster/then 3.5" space--repeated).
no... but i was reading about that this afternoon with classic columns..
in that section about "intercolumniation "
and i've done some column grouping at entry porches
Mike Smith Rhode Island : Design / Build / Repair / Restore
Edited 3/4/2005 10:24 pm ET by Mike Smith
I've used groupings of close set balusters in twos and threes, it makes even plain 2x2's look very cool, for very little extra money in material or labor. Actually it is quite suprising, it doesn't add as many balusters as you might think. I wish I had pictures.Edit. Then, when you do the math, each grouping is treated as a single baluster (1.5" baluster + 1.5" space + 1.5" baluster = 4.5" group)
Edited 3/5/2005 8:13 am ET by basswood
0.91 x 32 = 29. That's 29/32 inch. Of course, you have to be able to see that on the scale :). 7/8 inch is close enough.
>>>>>"Okay how to convert 0.91 to a fraction on a tape."This may not be the most practical solution but...I memorized the decimal equivalents to all of the 16 increments. When I lay out balusters I use a scientific calculator with a repeat function. I start my layout and then I just have to hit the equal sign to get my next tick mark. You can afford to be sloppy with your marks when you know the calculator is right on.
Jon Blakemore
Two ways to simplify the math, one way to avoid it altogether, and a lesson from high school geometry:
1) A tape measure with decimal feet. Sold as an "Engineer's scale", made by Stanley and others. About $12 at Home Depot. Also, a variety of surveying equipment is in deicmal feet, while other stuff is in feet and inches.
2) A metric tape measure. You know, like the rest of the world uses. Makes layout of many things very easy (especially if you are using metric materials). Also great for old work, since nothing is an even measurement in any system.
Or go to an analog computer and skip the numbers. Mark a bungie cord on even intervals. Stretch across our span, transfer your marks.
Or do the dividing technique from geometry class: Pick a nice even spacing that is larger than needed. e.g. 4" for 3.91". Angle the tape measure so that the 12x4=48" spans the distance. Mark off each 4" diagonal interval, which will be 3.91 along the horizontal. A plumb bob may be needed, or you can translate the angle up, once you have made a few marks and have fallen below your reference board. Or is that 5.5" for each 3.91" space plus 1.5" pickett? Anyway, you get the idea.
David Thomas Overlooking Cook Inlet in Kenai, Alaska
if you have a palm pilot (any pda with palm os), go the "free software" section about 1/3 way down on this page:
http://www.garymkatz.com/GaryKatzOnline-Links.htm
i use all 3 progs
Thanks. That's what I was looking for.
SO, how to YOU use the extra space left over. For example, after you figure do the math, your last picket will be, say, 1 inch from the post. It would look kind of out-of-place.
JMS,If you use the formula that Gene or I stated, or the palm program you will not have an "extra" space. I have laid out dozens upon dozens of handrails with my method and every time the formula has been correct.
I'm not always right but the math is.
Jon Blakemore
You obviously were either skipping class, or asleep when I was up at the blackboard.
You have flunked the stairbuilding carpentry course.
Go back to rough framing.
I can't get the links to work on that page.
Is there an easy formula for < 4
4 - 2?
Solve this equation to get the number of baluster spaces, excepting the spaces between end balusters and posts:
N = (L - 8 - B) / (4 + B)
I got lost on N!
Edited 3/4/2005 6:38 pm ET by Will George