Larsen Truss Roof

I joists on a roof.

Larsen truss roof.

Some builders argue that a proper larsen truss must be added onto the load bearing wall sheathing to be truly a larsen truss and not attached directly to the load bearing wall. A larsen truss is a system of adding large amounts of insulation to a house by putting light weight trusses around the perimeter separate from the structural parts of the building. In most cases conventional 2x4 studs hold up the roof load and the 2x4s are sheathed with plywood or osb. February 20 2017.

The larsen trusses get installed late in the construction schedule after the roof is on. Larsen trusses are non structural. When i arrived much of the roof had been framed but i was able to climb up for a little valley framing. A new roof was framed on top of the existing roof deck which was air sealed with high performance tape.

Modified larsen truss retrofit. These lightweight trusses are tacked onto the sheathing after a house is framed and sheathed. My modified larsen truss system requires conventional platform framing of the first floor walls second floor deck and then eastern balloon framing of the second floor bearing walls let in ledgers to support ceiling joists and rafters.