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Railing Cap (15)

When it comes to railing caps and all other guardrail parts, code requires each part be able to withstand a 200 pound load in any direction. Unfortunately, the common practice of cutting and then toe-nailing the railing cap between two posts just isn't strong enough. At best, two opposing toe-nails can only resist about a 100 pound force. Sure you can throw in a few more toe-nails but the joint is just notoriously weak and prone to splitting.

There are two much stronger ways of attaching the top railing cap. The first is to lap the railing over the face of the posts like the 3-D diagram shows above. This lapped joint allows screwing straight into the posts where two #8 deck screws on each end are sufficient to meet code. Not only are the screws much stronger when used in this way, but the chances of splitting are greatly reduced.

The other solution is to fix a baluster to each of the inside faces of the posts. The railing cap is then set on top of these balusters. Screws are driven straight down through the top of the railing into the ends of the balusters. Depending on the width of the baluster, this type of connection is potentially the strongest because it places all of the screws in what we call "shear".

Here at BestDeckSite, we pride ourselves on providing information of outstanding quality. To view example images and read more about when guardrails are needed, how tall they need to be, and what the maximum allowable size of openings are, check out the section on Railings & Stairs.