Is a deck considered part of the building?
(High River, Alberta)
In order to determine if I build a pergola on my deck, I need to determine if the deck is part of the building or if it is to be considered separate from the building.
This makes the difference between attaching the pergola to the house for support or to build support posts on the deck alone.
Pergolas are most often separate structures not attached to the house or building. They derive their strength from the elements of structural members in the construction.
And in these situations they can be built as part of the deck structure, either connected into the framing floor structure or surface mounted to the decking depending on the type of post anchoring means you use.
If you wish to connect part of the pergola to the house you must make certain that the pergola is also secured to an immobile footing system, equivalent to that supporting the house so there there is no independent movement of the pergola relative to the house.
So the minute you connect a roof overhang or a pergola to a house you must make sure the footings supporting the overhang or pergola are frost resistant and just as reliable as the foundation of the building it is attached to.