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Tips for Installing Balusters

About the Project

Building my own railing system in my new house was one of the most satisfying and nerve racking projects so far…and I’ve done a lot. I say that because any failure can have devastating consequences, especially since the first floor ceilings are 10’ (that’s a long fall in an open foyer).

Swapping out an old system with a new one can instantly give your house a custom look and doing it yourself is doable and saves tons of money.  I did my new railing system for about $2,000 but my builder was going to charge close to $8,000.

Common Questions When Installing Balusters

Most people reading this have never done this before and that’s why they’re reading this.  I was in the same boat when I did this in 2021. Below are questions I had and had to dig up from various sites.

1.                   How far apart can my balusters be?

First, always check your local codes to see what inspectors are looking for. The last thing you want to do is drill a bunch of holes in your treads that are the wrong distance apart. The most common maximum distance I’ve seen and read is 4”, meaning the space between balusters cannot be more than 4”. That code is similar in my location, however, I made the distance smaller in order to meet that requirement while ensuring the same measurement and number of balusters on each stair tread.  If I followed 4” exactly then the number and location of the holes on each step would vary.

2.                   How do I drill holes consistently on each step without measuring every step?

Make a template. Assuming you have open ended treads, the easiest thing you can do it take the top of a shoe box and cut it so it’s about 9” long and then cut the lip off of one side. This way you can put it onto the corner of the step. Once you figure out your measurement you can drill holes on the template so you can mark your steps.

3.                   How do I know how to space the balusters?

There might be some trial and error based on your measurement so DON’T DRILL until you’ve tested the spacing on several steps, especially the top and bottom where you tie into the newel post.

I figured out my spacing on my balusters before I installed the newel posts so that I could adjust their position and therefore the last gap. In my case, I was using thinner metal busters so only installing 2 on each step would not be an option to keep the gap under 4”. Therefore I knew I needed 3 per step. Measure the depth of the stair tread from the riser to the next riser. By this I mean don’t include the rounded edge on the front of the step; that’s just an overhang that doesn’t need to be factored for this. Once you know exactly how deep the step is and you know you need 3 per step, find the middle of the tread. That is your middle baluster. From here you are going to take the measurement from that middle baluster to the riser and multiple time 2/3. This will be how far the next baluster will be on either side of the center. I know you’re thinking “but there’s a smaller gap on from the last baluster to the riser than from the other 2 balusters”.  You are correct. It is 1/3 of the distance. However, remember the next step above is going to have a similar 1/3 gap which means the 1/3+1/3 on both steps equals the 2/3 gap that you were just worried about.  The gap is now equal.  For example, the tread is 9” deep from riser to riser (which excludes the rounded edge) and the middle is 4 ½”. Multiple 4.5 by 2/3 equals 3”, which means the next balusters (on both sides) are 3” away from the center mark. The remainder is 1 ½” away from the riser. The next step is also going to have a 1 ½” space. That 1 ½ from one tread plus the 1 ½” on the next tread gives a space of 3”, which is equal to the baluster spaces on the each step.

4.                   How do I secure a baluster?

The balusters can be secured using a small screw through the top into the railing.  If you are using a metal baluster there should be a hole predrilled that can be used.  If it is wood then you’ll need to drill a pilot hole. On the step where you drilled a small hole for the baluster to rest inside, you should put 2-parts epoxy glue in (be sure to stir it). This will secure the baluster at the top and bottom making it very sturdy. 

Tips When Installing Balusters

1.                   Plan, plan, plan.

You cannot plan too much when it comes to something like this. If I’ve never done something before, I will measure and measure again and then run a mock up of how it comes together to see if I’ve accounted for everything.  Many times through this process I will discover other factors that I hadn’t considered, make the adjustments and then do it again.

2.                   How can I protect the treads while I’m working and marking them?

There are a couple things to consider. First, when it comes to the markings, the easiest thing to do is to put some wide painters tape on the steps where the markings will go so you don’t have to erase, sand, paint, etc. to hide them. Second, when drilling your holes start in reverse so you don’t immediately start ripping out wood. This is a more gentle way of starting the process of drilling.

3.                   How do I make sure my balusters are straight?

Use a line level and hang from the railing directly over the mark on the tread.  Once the line is directly over the mark you can mark underneath the railing. After doing this on a couple treads you should be able to mark a template and then recheck every couple steps with the string to make sure you’re still lined up.

4.                   How exact do my measurements need to be on the baluster?

There is some wiggle room to fudge measurement and compensate if needed.  The key is to try and limit the amount of correction needed and to do it in an inconspicuous place. Remember, if you adjust 1/8”, which is barely noticeable, two times you’ve made a 1/4” correction.  Doing that once would be obvious but doing it over a handful of times, little by little, you won’t even notice.

5.                   Should I cut all my balusters at the same time?

I always say no to this. Why? Because sometimes you make a mistake in your measurement or sometimes the railing is slightly bowed and can’t be adjusted. If you cut everything and you made a mistake then it’s back to the store you go.


Also, remember, all three balusters on the same step are not the same height! This is also a good reason not to start cutting everything at one time. Stupid mistakes like this can result in only being able to use 1/3 of the material you just bought because 2 of 3 will be too short.

Identify Tools Needed to Install Balusters

Below are tools that are either critical to the job or that I would highly recommend to make your life easier. There’s nothing more frustrating than spending an extra 2 hours of time with inadequate tools just to save $40 by not buying what you need.

I am not the seller of these products, however, I have used these or similar tools in my projects.



Critical Tools

Recommended Tools

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