Deck balusters are essential for two reasons: they fill the role of both functionality and form. No one builds a big structure onto the back of their house without at least partially hoping it looks nice. What makes it looks nice is a series of small decisions, each of which blends with the others in seamless (and sometimes not-so-seamless) ways. This is why you’ll always read a great deal of advice pertaining to hiring a professional for a project of this size. You get experience, knowledge, and an artistic eye. But there’s no law against doing it yourself. If you are, here’s how you make your balustrade measurements.
Take a tape measure and figure out the distance from the bottom of the hand railing to the bottom of the rim joist. If the deck balusters you’re intending to use are going to fit flush against the decking surface itself, you’ll want to use that as your bottom measurement instead. With these measurements recorded, you’ll know how long you’ll want your decorative posts to be. This is important if you’re purchasing them prefabricated, of course, but it can also save you a lot of frustration if you’re carving them yourself.
You’re not done measuring yet. Take that tape measure and find the midpoint between two of the railing posts. Use a pencil and make a small mark where the center point is found. From there, make a small pencil mark every five inches leading away from this center point. Continue doing this until you reach the end posts. You’ll need these marks in place when you begin putting the deck balusters in to ensure symmetry. Some amateur builders disregard this important step, assuming they can just eyeball it while the project is in progress. This is a mistake. Don’t overestimate your abilities.
Finally, you’ll want to measure the distance between where the final pencil mark is and the last railing post. A good rule of thumb is this: if that distance is less than approximately two inches, you should move all of your deck balusters inwards two inches. It’s a small concern and it can be skipped if you aren’t detail oriented, but having a mini-gap at the end of your railing can take away from the overall aesthetic.
It’s worth mentioning that you should put a call into your local building regulators to ensure that your railings meet code. Remember also that even the smallest carpentry projects can be dangerous without the proper safety equipment, so don’t forget to put caution first.