How To Build A Porch Banister

Instructional Overview

  1. Gather the tools and materials.
  2. Lay it all out.
  3. Cut the top and bottom rails.
  4. Cut the balusters.
  5. Pre-drill holes in railings.
  6. Pre-drill holes in balusters.
  7. Attach balusters to the top rail.
  8. Attach the bottom rail to balusters.
  9. Test fit the railing.
  10. Attach railing hardware.
  11. Attach railing assembly to posts.
  12. Do a deflection test.
  13. Fill in gaps.
  14. Paint.

1. Gather the Tools and Materials

The first step in any project is making sure you have what you need to complete the job. Below are the tools and materials I used to build my own porch railing.

Tools You’ll Need

  • Tape measure
  • Sawhorses
  • Circular saw
  • Power drill
  • Hammer drill (if you are attaching to stone or brick)
  • Pencil

Materials You’ll Need

  • 3 ½-inch deck screws
  • 1-inch deck screws
  • Acrylic exterior paintable caulk
  • Attaching hardware
  • Top rail
  • Rail shoe (bottom rail)
  • Balusters
  • Concrete screws (if attaching to brick or stone)
  • Scrap 2×4
  • Paint

2. Lay It All Out

You are going to need a decent size work area to build these. I built them on my porch. You can build them in your basement, but keep size in mind. Two of my railings were nearly 8 feet long. An 8-foot-long railing, once built in my basement, cannot fit out of the basement (don’t ask me how I know this). Everyone has their own system of organizing their tools. My personal method is called haphazard or ad hoc, take your choice. Eventually, I will trip over the tool I need.

Measure the distance between the post you will be mounting the railings to. Subtract for the thickness of your mounting hardware. The ones I used were 1/4 inch each, so I subtracted 1/2 inch from the length of the top rail and shoe. Then subtract at least 1/16th of an inch to give you room to fit the railing in place (I used 1/8th).

3. Cut the Top and Bottom Rails

Cutting the shoe, or bottom rail, is a breeze because it is relatively thin. The top rail is trickier. If you have a table saw, it will make the entire job much easier. I ordered one for my job. It arrived the day after I installed the last railing.

Using a circular saw, set it to the proper depth to cut the top rail. Odds are, your saw will not cut that deep, so you will have to cut the top rail from the top and from the bottom. Make sure you mark both sides. My cuts turned out pretty good, but you might want to practice first.

4. Cut the Balusters

There are several types of balusters available at home improvement stores. I chose the square ones, simply because they are easier to cut and paint, and I don’t like the fancy grooved ones. Cut each to the desired length. The more accurate your cuts the better. If some of your balusters are exact, but a few are an 1/8th of an inch off or so, you are going to have some gaps to fill in with acrylic caulk later.

5. Pre-Drill Holes in Railings

You will be attaching the balusters to the top and bottom rails. Top rail first, shoe rail last. You would think that figuring out the spacing to make the balusters look uniform would be a daunting mathematical task. Normally, you would be right. But fortunately, we live in the 21st century, and there is an awesome online calculator that all you have to do is enter the length of the rail, the width of a baluster, and how far apart you want each baluster and it will calculate how many balusters you need and where to place the center of each one along the rails.

I never would have been able to figure this out without this online tool. Maybe you can, but save your sanity and use the calculator. Lay your tape measure along each rail and make a mark where the calculator tells you to. As a last check before drilling, lay the top and bottom rail side by side to ensure the marks match up.

Pre-drill a small hole at each mark. Be careful to drill straight. If you drill even at a slight angle, your screw will follow that path and either punch through the side of the rail, or pull your baluster off-center.

6. Pre-Drill Holes in Balusters

Find the center of each baluster and drill a small hole, just like in the railings. Drilling straight is equally important in this step. Also, turn on some music. Each of my railings used 25 balusters; you need to drill a hole in each end. This step will take a while.

7. Attach Balusters to Top Rail

Lay the top rail on the ground on its side. If you use a sawhorse, the weight of the baluster will bend and possibly break at the attachment point. While the length of your screw might vary, I needed 3 1/2-inch screws to sufficiently attach the balusters to the thick top rail.

Start the screw into the top rail and screw it in until the point is barely poking out of the bottom of the top rail. Align the hole in the baluster with the screw (the point in the hole will help ensure the baluster is centered). Use a power drill until the baluster is snug against the underside of the top rail and the screw is slightly countersunk. The drilling may twist the baluster some, you can twist it back with your hand. Repeat for all balusters.

8. Attach Bottom Rail to Balusters

With the balusters now firmly attached to the top rail, keep the railing on its side and line the bottom rail up with the balusters. Repeat the previous step for the bottom rail (using the shorter screws). Your railing assembly is now complete. Stand back and admire your work.

9. Test Fit the Railing

Measure how far off of the porch deck you want your bottom rail to be. Cut several small blocks that length off of your scrap 2×4. Position one at each end where the railing will attach to newell posts or other material, and one in the middle. Set your railing assembly on top of the blocks and check for fit. There should be a slight gap on each end. Once the railing is aligned, slide the attaching holders into the gaps. The fit should be snug or slightly loose. Lay the railing assembly back on the deck.

10. Attach Railing Hardware

Screw the attaching hardware to the ends of the top and bottom rails of the assembly. Ensure that the heads of the screws are flush. Even a small protrusion from the surface of the backside of the hardware will make installation difficult. If attaching to brick, stone, or concrete, use a hammer drill to pre-drill holes for the concrete screws.

11. Attach Railing Assembly to Posts

Place the railing assembly back onto the 2×4 blocks and check for level. If you live in an old house, level might not actually look level. Use your eyeballs for a cosmetic check. It’s better that it looks level than actually be level.

Once it looks level, screw all four ends into whatever is holding your railing via the mounting hardware. Use at least two screws on each end.

12. Do a Deflection Test

If you have a long railing, push slightly down in the middle. If it feels like it needs some extra support, cut one of the 2×4 blocks to size and screw it onto the middle of the bottom rail so that it provides more support in the middle. FYI, according to safety codes, your railing should support at least 200 pounds without bending or breaking.

13. Fill in Gaps

If your baluster cuts were less than precise for each and every baluster, you are going to have some slight gaps at the top or bottom of a few of them. Fill with paintable acrylic caulking.

14. Paint the Railings

This is probably the worst part. It’s tedious painting around all of those balusters. Painting the parts before assembly doesn’t really help. You can use wood fill to fill in the countersunk screws on the top rail if you desire a smooth surface. I just painted over them. Use high-quality exterior paint; you don’t want to have to do this again for a very long time.

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