Abstract: A press for assembling a roof trestle has an elongated support for positioning a bottom chord of the roof trestle parallel to and an elongated track member longitudinally perpendicular to the length of the support. A slide member is slidable longitudinally on the track member. An articulation device connected to the slide member interconnects one end of each of two supporting members for being at the ridge point of the roof trestle. Two further articulation devices respectively connect opposite ends of the supporting members respectively to carriages for positioning the same at the eaves ends of the roof trestle. Assembly tables on the support and supporting members are movable therealong for supporting the roof trestle chords in the positions parallel to the latter and a press is displaceable to each assembly table for pressing nail plates into the roof trestle chords.