Sizing Floor Joist

Chris october 23 2015 at 7 11 am.

Sizing floor joist. A 2x8 up to 12 feet. 2 grade of douglas fir are indicated below. When building a house or even a deck it is important to confirm you have the correct joist sizes spans and spacing before you get started. In typical deck construction with a ledger on one side of the joist and beam on the other the size of the joists is driven by the size of the deck and based on the general maximum spans mentioned above.

Bc calc performs engineering analysis to help our customers size beams joists columns studs and tall walls for their building projects. The span is 16 feet from the centre beam. It is simple to use yet flexible enough to analyze a variety of common applications. Floor joists or beams provide the below surface support for the wood subfloor of a room.

The floor joist spacing is the distance between the centers of any two installed joists. My house is 100 years old. Since the example house we are designing for is 12 feet wide we need to find in the floor joist span table a joist size and centering that can span 12 or wider. The larger the deck the larger the joists.

Common joist spacings are 12 inches 304 8 mm 16 inches 406 4 mm and 24 inches 609 6 mm. Maximum floor joist span for no. 1 psf lb f ft 2 47 88 n m 2. The problem is the noise when walking on the floor.

Choosing the correct floor joist size depends on your building application joist spacing and several other factors these include the length of the span as well as the type and grade of the lumber being used. This sample table gives minimum floor joist sizes for joists spaced at 16 inches and 24 inches on center o c for 2 grade lumber with 10 pounds per square foot of dead load and 40 pounds of live load which is typical of normal residential construction. How far apart do i need to have the floor joists and what size joists do i need for the floor. Therefore joists may run from wall to wall wall to beam or beam to beam depending on the size of the area they span and the structural design of the home.

1 ft 0 3048 m. Though joists may be any size that you desire using typical floor joist and beam specifications ensures that you can find hardware to fit the joists and that the floor provides adequate support for furniture and other items in a room. While most residential construction uses 2x8 joists with 16 inch spacing there are many other factors you need to consider when determining the proper joist span length. The user enters the member geometry adds loads holes and other relevant data and then selects a product for analysis.

Dead load weight of structure and fixed loads 10 lbs ft 2. 2x10 to 15 feet and 2x12 to 18 feet. Live load is weight of furniture wind snow and more. The joists span across a room or other area are supported on their ends and sometimes in their middles by load bearing walls or beams.

True floor joist span calculations can only be made by a structural engineer or contractor.