Bottom Chord Attic Not Connected

The remaining portions of the bottom chords shall be designed for a uniformly distributed concurrent live load of not less than 10 lb ft2 0 48 kn m2.

Bottom chord attic not connected. O no bottom chord splice directly over a bearing within a room. The attic space is considered uninhabitable but will be used for storage. Where ceiling joists are not parallel to rafters rafter ties shall be installed. Attic with storage is 20 psf versus 10 psf for attic with no storage.

Plating o do not reduce minimum plating defaults. A the top and bottom chord dead load. The architect had drawn in an attic condition that stepped up and over the floor joists at one end of the building. Recently a project came across our desk that was an unusual attic design.

A triangle is the simplest form of a truss and the bottom chord is the base piece. C determine the total load and proper load duration. B the top chord live include snow load as a live load and bottom chord live load. Metal plate connected mpc splice joints were tested in combined tension and bending to generate data that were used in the development of a design procedure for determining the steel net section strength of bottom chord splice joints of mpc wood trusses.

D sketch the loading diagram and calculate the reactions. The horizontal beam of the triangle of a bottom chord is used in this simple triangle truss construction. Toenail a truss into the top of the wall plate by nailing through the sides of the bottom chord at a 30 degree angle. O no top chord splices in haunch of attic room as shown below.

Several common wood truss splice joint configurations were tested at varying levels of. It s okay to do this. Lay a 2 by 4 across the truss with its bottom end on the top edge of the lower cord and centered on the mark you made between the end of the truss and its center. Center the 2 by 4 on the mark on the upper cord as well so that it extends from the lower cord at a 90 degree angle.

In other words the attic truss had no bottom chord. The design was 2 mono trusses sistered together at a ridge girder over the attic space. See table r301 5 for the above and then this note below the table. About the bottom chord.

The bottom chord therefore carries combined stress of both tension and bending of the truss. O limit attic room bottom chord l d to max 23 for example attic truss with 2x10 bottom chord lumber in the room should not have room wider than 17 9. A rafter tie forms the bottom chord of a simple triangular roof truss. Given that this section of the bottom chord is likely where one of the connector plates that hold the truss together is located you may need to nail through a metal plate on one side of the truss.