Installing synthetic handrail. No-Maintenance Exteriors:

Installing Synthetic Handrails
Around A Deck

Part 2 In A Series Of 3 Articles

In This Article:

Synthetic (PVC) post sleeves are slipped over 4x4 wooden posts. 6' sections of railing are assembled and installed between posts. Post caps are glued on.

Related Articles:
Skill Level: 3+ (Intermediate or Higher) Time Taken: About 8 Hours

By , Editor


This article describes my installation procedure of a synthetic handrail product from Monarch. While I tried to follow their instructions, I found them hard to understand, and some of the procedures they describe are impossible to do with ordinary tools.

In part 1 I described how the posts were attached to the deck framing.


After the posts were done, I installed synthetic deck boards on the new part of the deck. Deck with handrail support posts, before installing new synthetic handrail.


The first step was to slide the post sleeves over the wood posts.

In this picture I set the caps on top just to test the fit.


Post Sleeve Installation:

This is a post cover sleeve. It was 48 inches long, much longer than I needed.


I cut all of these sleeves to 40 inches long, on a miter saw. Cutting synthetic handrail post sleeves on miter saw.


Since these sleeves are so wide, I had to flip them over to complete the cut.

I strongly recommend checking the ends with a speed-square to make sure they are cut exactly to 90 degrees.

Many of the sleeves did not have a perfectly square end from the factory. I had to square-up one end before cutting the posts to length.

The sleeves easily slipped over the 4x4 posts, most of the time.


Synthetic handrail post sleeve over 4x4 post, end view. But there was a gap between the wood and the synthetic sleeve. This gap ended up getting squeezed when the handrail brackets were fastened, which caused more distortion to the square shape of the post sleeve.


Oops! Beginning On A Sour Note:

This is the first Monarch handrail section that I assembled.

When doing a project that involves repetition of a procedure, I usually build one or two assemblies to become familiar with the task before taking pictures of the steps in that procedure.

But this time I ran into problems right away so I got the camera out early, to record a mistake I (hopefully) won't make twice.

The first section of handrail needed to be 67 inches long. The Monarch railing sections were just over 72 inches long (6 feet). I needed to make the top and bottom railing components 5 inches shorter. Since these components are pre-drilled for the balusters (spindles), simply chopping a couple of inches off one end could result in baluster spacing at each end that are not the same. That would look really dumb.

The amount of reduction in length needs to be shared by each end of the horizontal components. So I cut 2½ inches off each end.

After assembling the first section, I discovered that the mounting clip would not fit on the top rail, which is what caused me to examine the design more carefully.

Suddenly I realized something. I had read the instructions, and they did mention the problem of the mounting brackets interfering with the balusters...




If the handrail needs to be shortened by a distance that is close to the baluster interval (i.e. 5¼"... baluster width plus space), or a multiple of that number (e.g. 10½", 15¾", etc.) then simply splitting the difference will cause a problem with baluster spaces that are not uniform, and there might be problems with the mounting brackets hitting the end-most balusters.

The solution is to shorten the handrail by a full baluster interval, (or just a bit less) and then trim an equal amount from each end.

I'll discuss this in more detail later.


I set the handrail in place. This looks stupid.


The space on the end is way smaller than the other spaces. This is poor practice.

I decided to set this handrail section aside (I used the parts on the stair handrails, which were very short) and open another new box of handrail parts.


Assembly Procedure For Railing Sections:

The procedure I used was substantially different from the instructions provided by Monarch. I installed eight sections of handrail and this worked well for me.

I measured the distance between the posts, both top and bottom. It's very common to have different dimensions for the top and bottom distances, so I'm not going to assume they are both the same.


The tan-colored piece is called the retainer. It slides inside the top cap.

But... these two fit loosely, and the top cap doesn't always sit in the proper position.


This is the bottom rail. Note the series of pre-drilled holes.


Quality Control Problems:

I lined up the retainer with the bottom rail, by inserting two screws into the screw holes. One end lined up fine, but this end did not.

This could be a problem if I hadn't caught it, because the balusters would be tilted after having to force an out-of-square section of railing between two posts.


I cut the bottom rail, retainer, and top cap to length on a miter saw.

This stuff cuts smoothly and easily.


Cutting Rails To Length:
Avoid Ruining Expensive Handrail Material

In my case I cut off about 5 inches from each railing. The baluster interval (space plus baluster width) is just under 5¼ inches, so this time I merely had to cut one end, and the spaces at each end of the handrail section were both close to 4 inches.

This isn't always going to be so easy. Keep in mind that if a full 72" railing is assembled, the spaces between each baluster will be 4 inches... and there will be 4 inches from the last baluster to the end of the rails. This 4 inch maximum dimension is determined by building codes, and is meant to prevent little children from getting their heads stuck between balusters. I'm not kidding.

For example: suppose I needed to cut 7 inches from a section of handrail. I could just cut 3½ inches from each end of the retainer and the bottom rail. But that would leave only a half inch of horizontal rail between the last baluster and the end of the rails. That does not leave enough room to attach the mounting bracket.

The right way to shorten a section of railing by 7 inches would be to first cut one full baluster interval from the retainer and bottom rail (that's 5¼ inches) and then cut the remaining amount (1¾") by cutting half that length (7/8") from each end. That would leave 3-1/8" of open space at each end of the railing section... well within the code-required maximum of 4" and still big enough to look similar to the other spaces.

To be sure there is enough room to attach the brackets, I would want at least two inches from the end of the rail to the side of the baluster. Since each baluster is about 1¼ inches wide, that's a minimum of 2-5/8" from the end of the rail to the center of the screw hole.

I strongly recommend being very careful when cutting these rails to length.

  • TAKE YOUR TIME. and plan your cuts.
  • Use a pencil to mark the cuts on the horizontal railing parts.
  • Make marks on masking tape if you prefer, because this PVC doesn't mark easily.
  • Set the end balusters in place and test if the mounting brackets will fit in the remaining space. In the engineering world we call that "doing a mock-up".

This product is too expensive to make mistakes, and with handrails it's easy to make mistakes.

I should know.



I fastened the balusters to the retainer, using #8 x 1½" stainless steel flat-head wood screws.

I found that the easiest method was to first fasten one baluster at each end of the retainer, then the entire assembly could hang over the edge of the deck and everything would lay flat.


I put the screw through the retainer hole, then I lined up the center hole with the screw tip and drove in the screw.

The instructions warn against over-tightening these screws, because the synthetic material will strip out. If this happens, the remedy would be a longer screw.


I carefully flipped the assembly over so the other ends of the balusters would hang over the edge.

I installed one 3" screw part-way (at the far end) to hold the bottom rail from falling down. At the near end I drove a 3" screw in tight.


To attach each baluster, I lined up the screw with the center of the spindle. There is a small hole all the way through the center.

If the screw missed that small hole, it would hit the larger cavity nearby and I would know because the screw would never get tight.


I set the assembly in place to check the fit. I rested the railing section on double-blocks of wood at each end, to keep the railing about 3 inches above the deck. Actually, it would have been better to use a 4x4 block for these spacers, but I didn't have any.

Note that I have not yet attached the top cap.


I set the upper mounting bracket in position and marked the holes on the post sleeve.

This is contrary to the instructions, which say to install the brackets on the top and bottom rails, then place the handrail in the opening and drill holes.

Ain't Happenin'

You CANNOT drill the top holes, or drive the screws, because the balusters are in the way.

These instructions just BLOW MY MIND. I'm convinced that the engineering staff at Monarch never actually tried installing their own product.


I drove three short screws through the retainer into the top cap. But... this also didn't go according to the instructions. I found it necessary to pre-drill a hole in the top cap. I used a Vix bit (which is used for drilling holes in hinges and stuff) because it cannot drill very deep. Drilling through the top cap would be a bad idea.


More Quality Control Problems:

Note how the top cap does not sit properly on the retainer. The arrow on the left points to a rib that is seated in a groove in the retainer. On the right, the arrow shows the corresponding rib that has fallen below the groove. As a result, the top cap sits tilted.

 Having some engineering background in the plastics industry, I can understand why this happens. (Difficulties controlling shrinkage as the hot plastic comes out of the extrusion machine.) But they need to do a better job.

I attached the mounting brackets to the bottom surface of the bottom rail. I pre-drilled the holes using a Vix bit.

I had to use a washer under the screw head because the holes in the bracket were way too big, and the screw head barely covered the metal. That's sloppy engineering.


I pre-drilled the holes for the upper mounting bracket.


I attached the upper mounting brackets with the stainless steel lag screws provided.


I positioned the handrail in place between the posts. It was a tight squeeze.


Connecting synthetic handrail to posts. I pre-drilled the holes under the retainer.


...and I drove in two 1" long screws with washers.


At the bottom, I pre-drilled the holes in the post.

Note the angle of the drill bit. The holes are too close to the top of the bracket, making it difficult to drill and drive fasteners.


I drove in the lag screws. Again, because the holes are so close to the top, one of these screws had to be driven on an angle. This is not a big deal, but it should be designed better... this leg needs to be about an inch longer.


One of the lag screw heads sat on an angle, which means that it might not hold as well.


The finished section of railing.


The center support block.

This was not installed according to the instructions.


Center Support Block - Their Way:

I cut the center support block to the proper length.


I attached this metal plate to the block with a flat-head screw.


Then I screwed the metal plate to the underside of the bottom rail.

But first I marked the exact mid-point of the bottom rail so this little support post would be centered.


The "flat" handrails after installation.

The stair handrails were much more difficult to install.


The post caps just sit on top of the post sleeve.

Leaving these until the end is wise because they would get in the way of installing the handrails.


Installing The Post Caps:

The Monarch post caps have plastic tabs inside that rest against the top edges of the post sleeve.

The distance from the underside of the top to the plastic tabs is just under 5/8".  Therefore, the wood post needs to protrude about 9/16" higher than the post sleeve.

Note: if the woods sticks up too high, the underside of the top surface of the cap will sit on the wood, instead of the plastic tabs resting on the cut end of the post sleeve. Since it's common for 4x4 lumber to be cut rather inaccurately, the cap could sit crooked.

My posts were all a fraction of an inch too short.


So I glued and screwed a thin piece of 4x4 to the end of the original post. I used a scrap of 4x4 that was good and dry.


Then I slathered a liberal bead of urethane construction adhesive to the top of the post.


I set the cap in place and lifted it off to see how the glue smeared. Any parts of the glue bead that did not smear got extra glue to make a thicker gob.


Once the glue dried (about a day) the caps were good and secure.


The Finished Product:

I must say that the results have a clean and professional look... at least from far away. The Monarch synthetic handrail system is a step above anything that I have ever built from treated lumber.

Being a maintenance-free building product makes this an enticing system, as long as the installer is aware of the quality issues and inaccuracies in the components.


The handrail combined with the skirting give the deck a completely different appearance.


Before and after comparison.

There really is no comparison. Expanding the deck, adding handrails and skirting was the right decision.

Continue to Part 3 - Stair Handrails 



Web Links: Monarch Deck Products

Tools Used:

  • Cordless Drill/Driver
  • Cordless Impact Driver
  • Basic Carpentry Tools
  • Miter Saw
  • 7/16" Socket

Materials Used:

  • Monarch® Synthetic Handrail, 6' x 36"
  • Urethane Construction Adhesive
  • Deck Screws

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Written May 17, 2005