Normal Floor Joist Size

In general practice 2x8s 2x10s or 2x12s are used when framing a raised floor instead.

Normal floor joist size. The table excerpt above is simply a sample and may not be valid for your region. Below is a table giving the minimum size floor joists needed for 16 and 24 on center o c spacing when using 2 lumber with 10 pounds per square foot of dead load and 40 pounds of live load. Surveyors and structural engineers use data from tables below to help calculate the size of timbers necessary to give adequate support to timber floors. Looking at this table you will see there is a choice in the size of floor joist 2 x 6 2 x 8 2 x 10 or 2 x 12 and there is a choice in the joist spacing 12 16 or 14.

Live load is weight of furniture wind snow and more. 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. It is again accepted that for normal household requirements the imposed. Wardrobes etc is known as the imposed load.

We ve included 2x6 2x8 2x10 and 2x12 joist spans and more. Two by 6 inches is a joist size frequently used in both indoor floors and as deck joists. 1 psf lb f ft 2 47 88 n m 2. Dead load weight of structure and fixed loads 10 lbs ft 2.

See our complete chart of floor joist size span and spacing requirements before you build. Common joist spacings are 12 inches 304 8 mm 16 inches 406 4 mm and 24 inches 609 6 mm. This size is no longer acceptable when framing a structure. The larger the deck the larger the joists.

1 ft 0 3048 m. The exact size necessary may be stipulated by the building code required for a particular structure. Maximum floor joist span for no. In the past 2x4s or 2x6s were sometimes used as floor joists.

True floor joist span calculations can only be made by a structural engineer or contractor. Floor joist span tables for surveyors floor construction. In joist sizes the larger size such as 6 inches represents the height of the joists while the 2 inch size represents the joist width or the area on which the floorboards sit. 2x10 to 15 feet and 2x12 to 18 feet.

A 2x8 up to 12 feet. 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.