Plumb the corners with a level and brace them with 2x4s.
Framing out attic.
Framing the opening can be easy if you can locate the ladder so that it is parallel with the existing ceiling joists.
The plywood will create a smooth strong ceiling without having to apply drywall tape and mud to the ceiling.
Nail the lumber to the edge going across the length of the timber so that the wood is held securely in place.
Hire an engineer to inspect your house s foundation and framing to ensure they can carry the extra load.
Standard joist spacing for the installation of attic flooring materials is 16 inches on center oc meaning the distance from the center of one joist to the center of the next joist is 16 inches.
A finished attic weighs a lot more than boxes of off season duds.
Our ceiling joists are 2 x 6 s.
So let s break this down.
Shim under the bottom plate to level it if necessary then nail it into the floor joists with 16d nails.
We enlarged the entry to the kitchen and made a header to frame out a doorway here.
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.
If you want your attic space to have a flat ceiling you ll need to add collar ties to the framing.
Note that only one stringer is needed in figure 17 because the ceiling joist provides one side of the frame.
If the ceiling joist does not provide one side of the frame cut a second stringer the same length as the first one.
If the framing in the attic shows evidence of physical damage further evaluation is needed.
Collar ties are horizontal members that like rafter ties extend from rafter to rafter but.
At a minimum you may need to strengthen the attic s floor joists which are often too shallow or spaced too far apart for the job.
I needed to cut one of those 2 x 6 s out to make our attic access larger.
Cut a stringer to this length.
Most attic ladders are made to fit between joists set at 24 inches on center.
Have a pro check the structure.
Run the plywood down to the top of the knee wall.
Place the next piece of lumber parallel to the first and nail it into position in the same way.
They are usually twice the size of the surrounding framing materials.
Install the lower header with joist hangers figure a and assemble the front wall on the attic floor.
