How to Reinforce the Roof by Bracing the Studs Running From the Rafters to the Joist

Measure the distance between the studs that run from the rafters to the joists.

Cut enough pieces of 2-by-4 to the measurement from Step 1 so you have twice as many pieces as the number of joists in your attic.

Install one of the pieces of 2-by-4 between two studs, one third of the distance from the top of the stud, by fitting it between them horizontally, then screwing through the studs and into the ends of the piece of 2-by-4 using 3-inch-long screws.

Place the next piece between the next two studs with its top face level with the bottom face of the first piece. Staggering the braces in this way allows you access to screw them all in through the faces of the 2-by-4s.

Continue installing braces in this way until there are braces between all of the studs.

Repeat steps 3, 4 and 5 for the braces that are installed one third of the way from the bottom. You should end up with two braces between each stud, with roughly a third of each stud above the top brace, a third between the braces and a third below the bottom brace.