How to Install Deck Railing

A deck without railing is both unsightly and dangerous. Well, let us say that it does not look finished and in some cases it is unsafe.

The idea behind installing deck railing ( balustrades ) is, safety and appearance. Remember to follow your local building codes.

Side Note:

If the deck rise is 30 inches or higher high off the ground (61 cm in Canada) the code requires a deck railing(balustrades).

The deck railing must be high enough to make it difficult for a child to fall off the deck but low enough to be comfortable to lean on.

The spindles or balustrades must be no more then 4 inches apart from each other.

Tools For The Job

An air compressor capable of putting out a minimum of 80 to 95 psi for the brad or finishing air nail er. (You can substitute with a hammer and 3inches finishing nails).

A screw gun or screw driver.

A spirit level to level and plumb the posts and railing.

A powered miter saw to cut the stock to measure. (you can substitute with a hand saw)

A tape-measure.

A drill and 3/8” drill bit


2”x 4″ spruce

2″ x 2″ spruce

2″x 6″ spruce

4″x 4″ posts (treated).

3″and 3-½” screws and nails.

Installing The Railing.

If the railing posts are already in place. Measure the distance between the first two posts. This is where the balustrades or spindles will be fitted once built.

If the deck has no posts you will want to locate the location where the posts will be installed.

Set the posts at same distance. Example: If the deck is 12 feet long, use three posts with the same interval between posts.

Once the post location is marked, cut a hole for each post to attach them to the deck boundary joists. (The deck rim) or perimeter boards.

You can apply either lug bolts or 3-½ ” deck screws to fasten the posts.

Now it’s time to build and fasten the balustrades to the deck posts.

Measure the length of the deck and make a mark at the middle of each post placement.

Cut a 2″ thick of 4×4 scrap to use as a guide and mark the placement of the holes where the posts will mount against the boundary joists. Drill holes in each corner of the squares and cut on the lines with a jig saw. Make sure to cut the holes so that the posts will go tight in the holes and against the boundary joists(deck rim) or deck perimeter boards.

Cut the 4×4 posts at 43-½ inches long.

Make a mark at 37-½” from the top of the post. This line will be at the same height with finished deck floor.

Insert the post trough the post hole and make sure that the mark on the post is flush with the finished deck floor.

Level the post from all sides and fasten it to the deck boundary joists with four lug bolts or six-3-½” deck screws.

Repeat the above steps for all posts.


If the holes are too big, you can use pieces of wood to shim them during the fastening process.