Modifying Garage Roof Trusses

I looked at couple of alternates and determined that we could work from within the garage attic modify the existing trusses so that the top part in the middle of the roof will be piggy backed on the flat part of the bonus room.

Modifying garage roof trusses.

You can modify the trusses but it s an enormous amount of work. Mark a line on each 2 by 4 at the top of the lower cord and the angled bottom of the upper cord. Step 1 measure the width of your roof trusses from inside to inside. Use a chalk line to draw a line along the floor parallel to the lower edge of the roof from one end of the attic to the other on both sides.

We looked at the structural arrangement of the garage and the surrounding area. Position the 2 by 4 so that the mark you made is on its inside edge with the width of the board against the upper and lower cords on the outside of the mark toward the eaves. Don t modify cut wood trusses. If you live in a house with engineered manufactured trusses then don t mess with them.

These trusses are usually engineered by a structural engineering company to carry a specific roof load. My recommendation is really simple. Measure in from the lower edge of the roof to a point 1 4 the width of the truss on either side of the attic. One use of trusses is for the support of a roof they are similar to roof rafters.

When a truss becomes damaged cut or modified there is a chance of a structural overload or that they will not perform properly. Also if you decide to do this you must work hand in hand with a licensed structural engineer that s familiar with wood trusses. Attic conversions are now possible by replacing the truss rafters with a shaped trusses or horizontal beams which in return create additional space. The role of the horizontal beam is to tie the truss together and carry the load that would otherwise be sustained by the support and vertical timber also known as the king post.