Composite Deck Railing Installation Tips

Installing a Composite Deck Railing Takes Some Serious Time and Effort so plan Accordingly

By Mark J. Donovan

Over the past several weekends I’ve been doing a deck makeover. Basically I removed all of the old pressure treated deck railings and replaced them with a composite deck railing system from Fiberon. I also replaced some of the Mahogany decking boards and the entire Mahogany apron that wrapped around the perimeter of the deck. Finally, I refinished the Mahogany decking with a teak colored transparent stain. Suffice it to say it was a lot of work however the finished product looks much better than what was there.

The composite deck railing installation part of the project was the most time consuming. Each 6 foot section of composite deck railing, along with a post sleeve and accompanying skirt and cap, costs around $200.

Consequently I was measuring twice before making any cuts. In addition, there are lots of pieces with each deck rail section. Besides the top and bottom rails, there are balusters, baluster inserts, a support rail post, mounting brackets and a whole assortment of screws. As a result, each section of composite deck railing took approximately 1.5 hours to install. The most challenging piece was the stair rail section. It took 4 hours to install it. Trying to get the right post heights, and figure out the appropriate angles was a real challenge. One simple piece of advice that can save you $200 in composite deck railing scrap, is to test cut a piece of lumber first to make sure you’ve got the proper rail lengths between posts and correct angles.

Removing old deck railing removing old deck railing posts.

Another useful composite deck railing installation tip is to make absolutely sure your 4×4 pressure treated posts are perfectly plumb. Otherwise you may end up finding out too late that the spacing between two deck posts is not exactly the same along the entire length of the posts, and subsequently finding yourself wasting a section of deck railing. I highly recommend measuring separately between two adjacent posts, both at the top and bottom.

First side of composite deck railing installed. Second side of composite deck railing installed.

Even though the 4×4 posts were plumb when you installed them, they can still differ 1/8 of an inch or more between the top and bottom due to a variety of reasons. The last thing you want to do is to measure at just the top of the posts, cut the top and bottom rail sections to the same length, and then find out the bottom rail section is too short.

All sides of composite deck railing installed. A view of the composite deck railing from a distance.

Also, immediately after sliding a composite deck sleeve over a 4×4 post, slide the skirt over it. You don’t want to assemble an entire section of composite deck rail system to then find out you forgot to put the skirt on one of the posts.

Another import tip is to make sure not to forget to install the center support post underneath the bottom rail section prior to fastening the bottom rail to the posts. The center support post, along with a level, helps to ensure the bottom deck rail section is at the right height and level, prior to fastening it to the posts. Also, trying to install the center support post is a major pain in the neck if you forget to do it until after you’ve installed the section of composite deck railing. A look at the mahogany decking boards.

One final note, finish the deck surface prior to installing the composite deck railing system. You’ll save time and hassles by staining the deck without any deck railing to worry about or to get in your way. I used a transparent stain and used a brush to apply it. I also only used one coat of stain. Applying two coats can potentially leave you with a permanently tacky deck surface.

For help on building a deck, see’s Deck Installation Bid Sheet. The Deck Installation Bid Sheet will teach your how to hire the right deck contractor, and help to ensure that your deck project is completed on time and budget.

Related Information

Additional Deck Building and Design Resources

Get Free Deck Building Price Quotes with No Obligation!

Fill out our 3-5 minute quick and easy form, and receive a free price quote on decks from one of our pre-screened and licensed deck contractors. This process is free and there is no obligation to continue once you receive your decks price estimate.