Geometry loading spacing bearing conditions etc.
Depth of residential floor truss spanning 25 0.
Span tables below illustrate common combinations of the multiple variables available.
Total load psf duration factor live load psf roof type 55 1 15 40 snow shingle 55 1 15 30 snow tile 47 30 snow 40 20 snow 1 25 20.
1 psf lb f ft 2 47 88 n m 2.
The shapes and spans shown here represent only a fraction of the millions of designs produced by alpine engineers.
Tcll 40 psf tcll 80 psf tcll 125 psf truss spacing truss spacing truss spacing.
Alpine truss designs are engineered to meet specific span configuration and load conditions.
Maximum floor joist span for no.
4 spans are clear.
1 in 25 4 mm.
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.
3 assumes composite action with a single layer of 3 4 wood sheathing glued and nailed or screwed.
True floor joist span calculations can only be made by a structural engineer or contractor.
2 grade of douglas fir are indicated below.
1 bearing size varies and is determined by loading conditions truss span and truss spacing.
1 ft 0 3048 m.
Dead load weight of structure and fixed loads 10 lbs ft 2.
Clear spans shown on this chart are presented under the following conditions.
Floor truss span tables alpine engineered products 17 these allowable spans are based on nds 91.
Live load is weight of furniture wind snow and more.
Live load 30 lbs ft 2 1436 n m 2.