Internachi certified professional inspector
Below is an example of two support posts for decks that are from homes built in the same year. One is built correctly, and the other is not. Go ahead and scroll down now if you want to try and figure it out and come on back to find the answer.
In this case, the deck on the left is how most homes I have inspected have looked and is incorrect. In Halifax, all decks that are attached to a home and those over 2 feet that are detached must have footings. This means that, just like a home’s basement or crawlspace, it needs to be buried below the frostline, or approximately 3 feet/ 1 metre. Furthermore, any deck being built in Bedford needs a lot grading permit as well due to the area's topography.
Why is it so important to have footings? A simple concept called frost heave. As water in the soil freezes, it expands and exerts pressure upwards on the post, leading to it raising or “heaving”. While it will drop back down in the Spring, the concern is that not only will it not settle in the proper spot (leading to uneven and unbalanced decks) but exerts pressure on the ledger board connection, where the deck is connected to the home.
Contrary to popular belief, while permits are required in HRM and most locales, there is no correlation between deck failure and whether it was built with a permit. Upwards of 90% of decks fail because the deck separates from the home and falls to the ground. Furthermore, while not visible in this picture, the deck on the left is secured only with nails that can easily come loose unlike the right deck that is attached with proper bolts.
COVID-19 restrictions are presently keeping large gatherings away from decks, but once large summer gatherings begin again there is an increased chance of deck collapses from decks weakened by frost heave. Please inspect your decks and if you have any concerns contact a qualified home inspector or contractor to ensure it is safe to use.