Actual Size Of 2x8 Typical Floor Joist

2 grade of douglas fir are indicated below.

Actual size of 2x8 typical floor joist.

Joist span and spacing is set by your local building code. If the joist spacing will be 16 inches 406 4 mm a joist size of 2 x 8 should be used even if the length is only 8 feet 2 44 m. Floor joists or beams provide the below surface support for the wood subfloor of a room. A 2x8 up to 12 feet.

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. 2x10 to 15 feet and 2x12 to 18 feet. Dead load weight of structure and fixed loads 10 lbs ft 2. Actual dimensional lumber is cut to a specific length width and depth.

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. A structure with a 10 foot 3 05 m length and joists set 12 inches 304 8 mm apart would require using a floor joist size of 2 x 8 50 8 x 203 mm. Mitek usp makes one for each joist size between 2x4 and 2x10 the one for 2x10s also works for 2x12s in its jlif product. 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.

However there is a difference between the nominal size what the lumber is referred to and the actual size. Joists that are closer together can support more weight which allows the joists to span a longer distance than joists spaced further apart. Maximum floor joist span for no. Live load is weight of furniture wind snow and more.

Something doesn t quite match up. If you can stop someone in the store to help explain the inconsistency they ll start throwing around a few words like nominal sizes and actual sizes and softwood lumber and hardwood lumber. Measure the actual width and thickness of a pine board like a 2x4 and then look at the sign above the rack. True floor joist span calculations can only be made by a structural engineer or contractor.

1 ft 0 3048 m. The maximum span distance for 12 inch spacing is greater by as much as 30 percent compared to 24 inch. 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. Common joist spacings for 2 by 10 joists and other dimensional lumber sizes are 12 16 and 24 inches.

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.