Working with Iron Balusters

Installers share tips on laying out, cutting, and fitting metal balusters to a wood staircase and banister. August 2, 2005

I am changing out an old railing and replacing it with a new oak handrail with iron spindles. I’ve done many stairs, but never with metal. The spindles are square at the bottom (using baluster shoes) and square at the top with a 1/2"-1" round. Does anyone have any suggestions? It doesn’t seem too much different from wood spindles, but any tips and tricks would be much appreciated.

Forum Responses
(Architectural Woodworking Forum)
From contributor P:
Iron balusters are definitely increasing in popularity these days. About 1/4 to 1/3 of the stair systems I have done the last couple of years have upgraded to iron balusters used in conjunction with traditional wood newels, posts, and handrails. The basic principles of installation don't vary too much from using wood balusters, but you should be able to add a significant up-charge for installation.

You will need a good tool for cutting them to length. I use a 4 1/2" angle grinder with a thin cut off-wheel. A friend of mine uses a port-a-band saw. Since every one of the balusters must be cut to length, you will be able to save a significant amount of time by setting up a jig to cut to length as well as hold in place while cutting.

I drill a 9/16" hole in the tread to a depth of 3/4", and then use one of the cut off pieces to drive into the hole to square it up. A 1/2" hole is drilled into the bottom side of the handrail. These sizes will hold the baluster firmly in place with no need for epoxy as I have seen suggested in some installation instructions.

Some of the shoes come with set screws to hold them in place (others use adhesive or epoxy). A drop of thread lock will prevent them from falling out and becoming lost. You might also need a thread tap. I usually encounter a few shoes that aren't threaded all the way through or have paint or other junk in the threads.

Use care with the finishes. Some can be hard to touch up if damaged. I have found the black wrought iron with the textured sand like finish to be particularly vulnerable to damage. It's a soft finish and can scrape off easily by merely letting an air hose rub against it or by bumping it with other materials. Your hands can also leave white marks if it slides in your hands. A black felt tip marker easily touches this up though.

Also, using iron balusters will add significantly to the weight of the balustrade. Your newel posts, handrail fittings, and connections must be anchored and secured very firmly to prevent too much lateral movement. I had one particular staircase, a single run top to bottom, volute at the bottom and a gooseneck fitting at the top and attached to a newel post, that had so much lateral movement that the only way to correct it was to add a intermediate newel halfway up the stairs.

I noticed one thing in your post. You didn't mention replacing the treads in conjunction with replacing the railing. Are the existing balusters not drilled into the tread? If they are drilled, which is probably a 3/4" hole, how are you going to install the iron balusters?

Another note: Many older balustrades have two balusters per tread. You will need three iron balusters per tread to meet spacing code requirements. The learning curve for iron balusters isn't too big. These are a few of the things I have come across that hopefully will help your installation.

From contributor R:
To add a couple things to what’s been said, on the ones you have, for easy install, I cut off part of the dowel (leaving about 1/2 to 5/8"), drill a 1/16 hole in the tread about 1" deep, put in a bit of construction adhesive on, insert it in hole and then up in to the rail 1/2", hold it up tight and then tighten the shoe. If you’re using construction goo, have a rag and paint thinner handy.

You will probably have to play more with the layout, especially on the balconies, as the layout usually has pattern. For instance, on the job I'm doing now the pattern is for a twist, plain, twist, basket, and keeps repeating. But they also want a run to start with a P and end with a P, so I need to play with layout spacing more to get it to work out.

If there is a knee wall involved and if it's high, this means extra time as you cut both ends, and you will need a square hole in rail. You will probably have to cut to allow the detail to have proper height, and this can mean a pita working with the amount of square required to slide the shoe high enough to install.

One way around this is if the knee wall is quite high is to plow the rail and make up a filet, then make up a shoe and filet for the bottom, then cut and angle on both ends of baluster. Then slide in and install the filet top and bottom.

It like a lot of extra work, but a it’s a workable answer to overly high knee walls. The standard way to do knee walls is with angled metal shoes, although they're never the right angle and need to hold to a belt sander to custom fit. I used to cut with a metal chop saw, but find a port-a-band mounted to a table with a hold clamp – that should work best.

From contributor D:
What I normally do is after I drill holes close enough to the square bottom part, I use a used half inch square chisel (one that you use with a drill for mortise holes) to finish the holes on the treads or the floor. Whatever the case might be this gives you a clean professional look and square to one another or the tread's edge.

From the original questioner:
I am using false end treads on top of old 2X treads which I found out causes a problem moulding on false tread. They only come down about 1 3/8’s, which is not enough to cover the 1 1/2 plus gap left to trim the skirt since it had carpet originally.

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Comment from contributor F:
We have been doing a lot of iron pickets lately. All points covered previously are excellent. As far as securing the ballasters, hold the shoe up and screw in set screw. Dampen bottom hole and put in a little polyurethane glue, then shoot some power grab in top hole. This allows you to do a whole run at one time. Set pickets into place and let dry overnight. Scrape foam-out on bottom hole and move shoe down and secure. Clean up top of picket of any power-grab. After all picket are set, gently jar newel post and listen for any rattling of pickets. If there is rattling, it is usually top of pickets. You can find loose pickets and apply enough power-grab to tighten them up.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor M:
I have been using a hot glue gun to install both the iron balusters and their shoes. It sets up quickly and easily holds everything in place. I drill a 3/4" hole at the bottom, and ½ hole at the top. I hold the baluster up in position and squeeze a healthy amount of hot glue into the spaces around the baluster. Within 10 seconds the glue is set, and I add more around the baluster about 1 inch up and slide the shoe over it, and again it’s set in about 10 seconds. Any excess can be picked off with your finger or knifed off. I don't even use the allen screws, and I haven't had a call back yet.