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#### bulldog2048

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Can someone tell me what the formula is to figure out how many balusters and the spacing i need to put on my railing on my deck. I amd redoing it all and i cant seem to get them right.

#### Willie T

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This is similar to how I do it, but much of my method is done in my head, so I copied this from another site. It's probably easier to understand than my way would be. :huh:

BTW.... he doesn't say it, (and I'm not positive of this), but I believe he is using a flat, level measurement in step 1. I, on the other hand, work with angled measurements, so that's why you aren't hearing too much about my method... it can get a bit confusing.
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Step1
Measure the staircase length between each rail post in inches, and write down the measurement. You may need someone to help hold the tape measure in place or take several measurements if your staircase turns.

Step2
Determine the local building code requirements for spacing balusters by calling your local building department or looking for the standards online. An industry standard is 4 inches, but your area may have different requirements so double-check to ensure accurate placement.

Step3
Refer to the balusters you've chosen and write down the width of the balusters in inches.

Step4
Add one baluster width to the staircase length.

Step5
Add the baluster width and the space between each baluster together. Then divide this number into the staircase length (plus the additional baluster length). For example, a 2-inch wide baluster with a required space of 4-inches and a 192-inch long staircase: 2 inches + 4 inches = 6 inches; 192 inches + 2 inches = 194 inches; 194 inches/6 inches = 32.33.

Step6
Round the fractional part of the number from Step 5 (after the decimal point) down to the nearest whole number. This is the number of balusters you'll need for the project and, for this example, you will need 32 balusters.

Step7
Multiply the number of balusters you need by the baluster width, and then subtract this number from the staircase length plus one baluster width. For example, 32 x 2 = 64; 194 – 64 = 130.

Step8
Use the final sum of 130 from Step 7 and divide the number of balusters you determined you'll need plus one more baluster. For this example, 130 / 32 (+1 baluster) = 3.93 inches between each baluster. If you feel 3.93 inches is too close, you can add another baluster.

Step9
For an odd number of balusters, start at the midpoint of the staircase run and install your first baluster. For an even number of balusters, you'll be off the midpoint by 1/2 the space amount. Working out from the center, install each subsequent baluster the distance as determined in Step 8.
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Here's a calculator that may help:

http://www.virginiarailingandgates.com/calculations_picketspace.asp

As a hint in ensuring equally spaced balusters...... most installers determine their spacer measurements beforehand, cut them all, and install the spacers as they go. This keeps everything tightened up and in line. But make sure the first baluster is perfectly plumb.... and check for plumb as you go. (You COULD have cut one or two spacers off just a little, and it will throw you off.) We who may not be all that accurate in all of our associated work often find that we probably should only cut a few of the fillet spacers at a time. :whistling2: :yes:

#### 47_47

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The problem is that you have one more space than balusters. For uniform spacing, what works for me, is to measure the distance between the posts and the baluster width. Use the smallest width for not uniform (turned) balusters.

Lets say 160 inches and a 1½" wide square baluster. Max spacing at 4". 4+1½"=5½". 160 (length)/5.5 (baluster and spacing)=29.09". Multiply 29 x 1½ (baluster width)= 43½ inches of balusters. 160 (length)-43½=116.5 (inches of spaces). 116.5/30 (one more than the number of balusters)=3.883" or 3-7/8" space.

If the spacing is over 4", add one more baluster.

#### bulldog2048

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Thank you very much this helps me out alot. I am going home tonight after work and try it out.

#### Willie T

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This whole calculating thing is one of the reasons I smile when people apologize for having me mount balusters on treads. :whistling2:

#### bulldog2048

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Yeah i can understand that for sure. i actually am not doing stairs, i guess i said the wrong word. I am putting spindles, (i guess that is what they are called) on the rails around the deck but this will help me figure out how many to put on there.

#### Willie T

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Yeah i can understand that for sure. i actually am not doing stairs, i guess i said the wrong word. I am putting spindles, (i guess that is what they are called) on the rails around the deck but this will help me figure out how many to put on there.
Do you have spindles with the dowels in the bottoms?

#### bulldog2048

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NO I SURE DONT, I BOUGHT THE 1.25 X 1.25 ONES THAT ARE CUT AT A ANGLE ON ONE END. THIS IS LIKE THE RAILS I AM DOING.

#### Willie T

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You're in great shape. You don't have to do even half of all that stuff I posted.

Here's all you do:
1. Find the middle between your big posts
2. Cut a little block of wood 5" long (This will be your center-to-center layout spacer... just a little shorter than the legal baluster spacing to keep you safe from the inspector)
3. Starting at the center, use that piece of wood to lay out baluster center marks all the way to one of the posts.
4. Does it leave you way too close to the post with the last layout mark? Or about right?
5. If about right, you have your layout for the spindle centers.
6. If too tight on the end, go back and lay it out again. This time......
7. Begin 2-1/2" short (or long... doesn't matter) of the center mark. (That's 1/2 of the length of the layout block)
8. When you get to the end, you will have moved that last mark 2-1/2" farther away from the big post. Should be looking pretty close to right
9. Lay out the other end.
Now, if you want to be EXACT, you will have to divide the errant distance of that last center down by the post by the number of spaces in that end of your layout.

ie: You're an inch too close to the post to suit you. (like that's ever going to happen)
There are eight spaces. (Aren't we lucky?)
Each space will have to lose 1/8", all the way back to the center of your layout. (1 inch divided by 8, the number of spaces)

So, (in this simple example) you cut the 5" layout board 1/8" shorter, and do the layout again. You should be dead on.

Of course you KNOW you will not be off an even inch number, and the math is not going to ever work out this easy.... but you can see the idea from our simplified exampe.

********

Oops! I forgot to figure in the half thickness of the spindle.... so you're STILL going to be off a little. But now that you understand the principle, I'll let you go ahead and do the little bit of extra math to compensate for my 5/8" mistake.

Hint: it works out to taking about a 1/16 more off the length of the marker stick. Not much. But by the time you move each mark over that extra 1/16" eight times, the accumulated gain makes up for the 5/8" on the end.

#### CVGFir

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Here is how I used to do it....

1. Measure the distance between your newel posts.... let's say ...74".
2. Add 4" to the width of one baluster....for example 4" + 1.5" = 5.5". 4" is code for maximum space between balusters.
3. Divide distance between newels by this number.....74"/5.5" for example
5. Multilpy 13 times the width of one baluster gives you 19.5" which is the space the balusters will occupy.
6. Take the distance between the newels - 74" - and subtract the space the balusters will occupy - 19.5" - and that gives you 54.5" which is your opening space.
7. 13 balusters means you will have 14 spaces between so divide 54.5"/14 and that gives you 3 7/8" space between the balusters.

Easy to do once you know how but gets a little cumbersome doing it time and time again.

There is an app for the iPhone called BalusterPro that I use now that will do these calcs for you in seconds that works pretty well. Here's a link...www.gabrioconstruction.com

Good luck

#### My Old House

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According to US building codes, ballusters need to be located so that a 4" sphere cannot pass through the guardrail up to a height of 36" above the floor surface. The code expands this limit to a 6" sphere between 36-42" AFF, but it looks like you will not need to worry about that . . . so this is the only rule you need to follow.

As for how to place the ballusters to copmly with this code - just measure the distance between posts (in inches) and divide that number by (4"+thickness of balluster at its narrowest point) = 6.5" in your case. Then add the remainder (less than 6.5") to 6.5" and divide by two - or just locate the midpoint between posts and either (a) center a balluster at this location, or (b) center the gap between ballusters at this point. Work your way outward from the midpoints.

#### Chippy21

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Perfect uncomplicated spindle spacings

I read all the posts here and got so confused! After trawling the internet the simplest and most accurate way I could find was at
http://www.carpentry-tips-and-tricks.com/Spindle-spacing.html.
I think it makes it loads easier just working in millimetres instead of trying to divide inches/fractions which is complicated!
Here is a quick breakdown,
Put the spindles in situ, all against each other.
Measure the remaining space horizontally to the newel post.
Divide this number by the number of spacings (one more than the number of spindles)
Et voila! this is the space between each. If its more than 100mm add another spindle to the mix and recalculate. I had spaces of 85mm, which looked smart. Best thing about it - the missus is happy :wink:

Hope this helps :thumbup:

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