Nail the 2 by 4s to the top of each ceiling joist with 2 16d nails.
Framing an attic ceiling.
The plywood will create a smooth strong ceiling without having to apply drywall tape and mud to the ceiling.
Install and paint the ceiling use screws to attach sheets of birch plywood to the angled ceiling over the insulation making sure to drive the screws into the ceiling joists.
When framing your ceiling if the ceiling joists are not going in the same direction as the roof rafters 2 by 4s are added running in the same direction as the rafters.
Space these boards 4 ft.
Collar ties are horizontal members that like rafter ties extend from rafter to rafter but.
If you want your attic space to have a flat ceiling you ll need to add collar ties to the framing.
Run the plywood down to the top of the knee wall.
If you have attic trusses not conventional trusses the members will be sized to support living space.
Ensure insulation extends to the outside edge of the exterior top plates and to the peak of the cathedral ceiling.
Friction fit insulation between and parallel to the attic framing members.
The ceiling load may include items like drywall ducts recessed lights bathroom fans and attic insulation.
However in some cases the joists are intentionally built strong enough for the homeowner to later build out the attic.
Attic floor framing attic floors are made with floor joists or with truss members.
Most houses attics are built without flooring and are not designed to carry the heavy load of finished space.