The top chord is always in compression and the bottom chord is always in tension.
Girder floor truss.
Truss a pre built component that functions as a structural support.
They have a top chord and a bottom chord separated by diagonal webs and vertical webs.
Top chord bearinga floor truss support condition in which the truss load is transferred to the bearing or support through the top chord and 4x4 block end detail.
Span tables below illustrate common combinations of the multiple variables available.
Floor trusses are not fire code friendly.
When the 4x4 block length is extended this is referred to as mid chord bearing.
This girder is made of similar trusses built and fastened together to act as one unit to support the load.
Floor truss span chart each individual floor truss design is unique based on multiple variables.
Forming the top of the floor truss.
The wide nailing surface provides for easy gluing and quick accurate attachment of sheathing reducing squeaks and improving floor performance for the life of the structure.
A girder truss is designed to support other secondary roof supports.
Geometry loading spacing bearing conditions etc.
Tcll 40 psf tcll 80 psf tcll 125 psf truss spacing truss spacing truss spacing.
To strengthen a truss the fabricator may double its top and bottom chords make side by side girder trusses use larger truss plates or stronger wood or use some combination of these techniques.
These are often pre fabricated and sent to a construction site.
Floor trusses are built with 2x4s or 2x3s with a wide stable bearing surface that is easier to work on and around.
Repairs are costly and time consuming.
In jurisdictions where recent versions of the irc fire code are enforced a protective membrane must be installed on the underside of plated truss floor framing.
Girders are trusses specially designed to carry extra loads from framing and equip ment.
Girder trusses have a long straight design.