Building a deck is a great way to extend the outdoor living space of a home or business. Making sure it is solid and structurally sound from the ground up though, is often a matter of 4×4 vs 6×6 deck post. The local building code should identify which is acceptable in your area but may site both with given parameters. So, which is better?
The load capacity of a 3-foot #2 grade 4×4 is 17,426 pounds, and a similar 6×6 is 20,834 pounds or 16% better. However, an 8-foot 4×4 supports 6468-pounds and 2339-pounds at 14-feet, while a 6×6 is 18032 and 10550-pounds respectively – or 64% and 78% more load capacity. So, for posts 3-feet and shorter, it’s a matter of preference, above 3-feet use 6×6.
In this article, we’ll explain 4×4 and 6×6 posts, when and where to use them, how to secure them to a beam, and the spacing between post supports. We’ll also look at posts for deck stairs and deck railings. By the end of your read, you’ll be able to identify which post is better for your deck construction to ensure it is structurally sound and code compliant.