Design Timber Floor Joists
True floor joist span calculations can only be made by a structural engineer or contractor.
Design timber floor joists. 1 psf lb f ft 2 47 88 n m 2. The allowable clear spans have been calculated in accordance with bs 5268 2 2002 structural use of timber part 2. Dead load weight of structure and fixed loads 10 lbs ft 2. Live load is weight of furniture wind snow and more.
1 grade 2 by 6 douglas fir larch joists spaced 16 inches on center. 2 grade of douglas fir are indicated below. 1 ft 0 3048 m. Code of practice for permissible stress design materials and workmanship and bs 5268 7 1 1990 structural use of timber section 7 1 domestic floor joists.
The floor joist spacing is the distance between the centers of any two installed joists. As an example consider a room with a floor area of 10 feet by 11 feet 2 inches built with no. Maximum floor joist span for no. 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.
See the image below for an example of joists spaced 16 on center 16 o c. Use a design value table to find the fb value for your floor joists.