How To Make 2x4 Floor Trusses

2 grade of douglas fir are indicated below.

How to make 2x4 floor trusses.

Live load is weight of furniture wind snow and more. The multiple bearing conditions make matching existing floor heights much easier when using floor trusses. Build a fink truss to bolster a floor roof or deck. Fink trusses were originally invented for the purpose of beefing up bridges but many contractors now use them to increase the strength of interior structures.

While they flex more than i joists they flex less than lumber trusses and use less wood. Trusses can be constructed with smaller sized lumber than rafters and often their cost is not significantly higher than normal rafters. Basic lumber design values are f 2000 psi f 1100 psi f 2000 psi e 1 800 000 psi duration of load 1 00. Maximum deflection is limited by l 360 or l 480 under live load.

Bottom chord bearing bottom chord bearing trimmable ends top chord bearing and mid block bearing are all available. Spacing of trusses are center to center in inches. 1 ft 0 3048 m. There are online span calculators available that tell you the maximum span for.

Step 1 lay the two pieces of 2 by 4 by 144 inch lumber on a worktable. Floor trusses offer four different bearing conditions for a wider variety of uses. 1 psf lb f ft 2 47 88 n m 2. Trusses are beneficial in that the open spaces in the middle make it easy to run utilities through them.

Maximum floor joist span for no. Raised floor living in conjunction with southern forest products association developed a table to help understand how trusses are built. I joists offer only one bearing. In a fink truss the internal joists are arranged in a w shape ensuring even weight distribution from one end to the other.

Dead load weight of structure and fixed loads 10 lbs ft 2. Most spans are typically 10 to 12 feet so we typically use 2x8 or 2x10. Floor truss span tables alpine engineered products 17 these allowable spans are based on nds 91.