Frame by Frame: One-Story vs. Two-Story Framing
In a single-story dwelling you obviously don't have to worry about a floor over your head, so engineering and structural things may not be the same as what you'll need to support a second story.
With a second story, you have to build it with larger lumber to support the second floor. In addition to larger lumber, several items are needed to give the home more support when framing for the second floor.
"All houses are engineered structurally, and on a single-floor home, you wouldn't have nearly as much structure as you have on a multi-level dwelling. There will be a lot more anchors, straps, tie-downs and beam work," said carpenter Jerry Miller.
While first-floor supports are needed to account for the additional weight of a second floor, the walls are pretty much the same as those of a single-story home. What this means is that the first-story ceiling joists will also serve as the floor joists for the second story. This will carry through to each subsequent story, no matter how many you might have in the home.
Stairs Add New Challenges
Also, if you have two stories in your home, you'll need a way to move between them. That means adding stairs — and a new set of challenges to the framing process. The challenges are to make sure that all flooring materials are considered because by the time all the framing and finished materials are on the stairs, you can't have a variance of more than 3/8ths from top to bottom of each riser, which is a critical issue. Most building inspectors are very particular about this.
Crafting stairs for a two-story home is a perfect example of why we keep emphasizing "precision" when it comes to framing a home. And since stairs are a necessity for a multi-story home, you'll want to hire a subcontractor who specializes in stairs.
Construction Advice: The codes for residential stairs can vary widely from city to city — everything from the height, width and depth of the individual steps as well as the size of the landing and handrails must follow certain guidelines. Failing to meet these requirements will cause delays in construction. Avoid this common headache by making sure that your builder and stair subcontractor check out the stair codes for your area — and incorporate them into their work.