How to Finish an Attic With Trusses

Measure the attic's ceiling gable from the tip down to the floor--or wherever you want the beam to finish. Using the carpenter's level, measure and record the angle of the ceiling's point and the angle at which the beam will meet the wall. Measure the beam, allowing for room on each end to match the attic's angles. Draw the respective angles onto the wood to ensure that the trusses fit flush against the ceiling.

Saw the beam at the two angles and hold it up against the attic's gable to make sure it fits properly. If it does, lay the truss face-down on the whole beam and mark the respective length with the pencil. Saw the beam and repeat the process for any remaining trusses that you wish to install.

Decide whether or not you want to add crossbeams to your trusses. These may not be practical additions if your ceiling is low, but you may still want to add them on the trusses that lie against the wall. If so, line up one of your newly-sawed trusses, making sure that the points are fitted together as they will be when installed. Measure the distance between the two beams as well as the corresponding angles. Mark the measurements for the crossbeams on one of the whole beams and saw. Nail the crossbeams to the truss frame from the outside of the truss beams.

Sand down the truss beams to avoid splintering. Align the truss beams with their corresponding gable and nail into place from the outside of the beam.