You have reworked your floor plan, adjusted the orientation and placement of the window to take advantage of southern views and exposure, and tweaked the roof line to match the homes you have imagined for months and years. But how much thought do you give to your floor framing system? Unlike floor finishes, the floor framing system will become part of your structure for the life of your home.
In addition to several wall framing systems, you can choose from various types of floor framing systems. Dimensional lumber is often the most economical choice but that is not its only advantage. It is also durable in shipping and installation. Kiln drying and protection from the elements in transit and during construction helps reduce swelling across the wide grain and keep lumber dimensionally stable.
Prefabrication is great for this. However, if the lumber is exposed to moisture, but then permitted to thoroughly dry out, the moisture will not have a significant detrimental effect on the structural integrity of the lumber. Therefore pre engineered floor framing system is the go-to material for decks exposed to the weather.
Readily available at local lumber yards, dimensional lumber can be sized using tables in the local building codes and doesn’t require the loading analysis to be sealed by a professional engineer. Rules for notching, drilling holes, and general installation are standardized in building codes across America and are also familiar to carpenters and other trades.
As there is some variation from dimensional lumber floors, installation instructions are provided with the floor material. This includes details on drilling holes in the OSB webs, both size, and placement of holes is very flexible in I-joists, some manufacturers even provide pre-pressed holes that only need to be punched out to run wires.