Modifying Roof Trusses

If you really want to modify the framing of your attic and roof then consult with a licensed professional structural engineer.

Modifying roof trusses.

Rather than trying to make a scissor truss do a raised center. You can modify the trusses but it s an enormous amount of work. My recommendation is really simple. The upper cords or rafters form the peak of the roof.

Measure the width of your roof trusses from inside to inside. Click here to get free fast bids from local structural engineers who can help you modify your trusses. 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. While they look the same you probably didn t notice the subtle differences.

These trusses are usually engineered by a structural engineering company to carry a specific roof load. To do this i d have to cut out and raise the bottom chords of the trusses. Most common attic trusses for homes and garages are made with 2x4 s. Just as there are many types of roofs with many roof parts there are many different types of roof trusses this extensive article explains through a series of custom truss diagrams the different truss configurations you can use for various roofs.

If the house is new enough that you know how built the trusses give them a call. If you modify the existing trusses i have one suggestion. If you live in a house with engineered manufactured trusses then don t mess with them. If a lot of trusses are damaged or one has been significantly modified or cut then consulting a engineer is wise.

Trusses must be modified to allow room for attic space. Also if you decide to do this you must work hand in hand with a licensed structural engineer that s familiar with wood trusses. While this article focuses on configurations we also have a very cool set of illustrations showcasing the different parts anatomy of roof trusses. Let s compare common roof trusses with the roof framing materials that were used in your parent s house.

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. Your parents roof rafters were probably made from 2x8 s and could have been 2x10 s or. The lower cord or joist forms the lower horizontal of the triangle supporting the attic floor and top floor s ceiling. That way the last few feet at each end of the truss will not have to be modified and the changes should be less extensive.