Installing the Stairway
Build two ledges to hold the stairway in the rough opening using 1 " x 4 " temporary slats which extend across the ends of the rough opening . Each slat should extend approximately 1 / 2 " to 5 / 8 " into the rough opening . If the length of the rough opening is not exact , be sure that there is enough ledge to overlap each end of the stair by 1 / 4 " to 3 / 8 ". The slats should be nailed securely enough to hold the weight of the stairway ( Fig . 4 ).
Do not place any weight on the stair until permanent nailing is completed .
With a helper in the attic , carefully raise the stairway into the rough opening , and position it on the ledges formed by the slats . Ensure that the plywood panel of the stairway is not blocked by the slats and is free to swing open .
Be sure the stair does not shift in the opening and come off the temporary slats .
As an extra precaution , temporarily drive an 8d nail through each side jamb of the stair , just above the stop blocks and into the rough opening frame ( Fig . 5 ). Do not drive the nails in so deeply that they will be difficult to remove when the permanent nailing is completed .
Step 3 Carefully open the stairway from below .
Do not stand on the stairway at this time .
Make sure the stairway is square , level and firmly situated in the rough opening . Blocks of wood or plywood can be used as shims .
✎ It is normal for the stair frame to become bowed while in inventory , because the wood parts are often subjected to strong spring tension for several months before installation . The frame , however , can be easily straightened by using nails and shims .
Permanently mount the stairway using 16d nails or 3 " lag screws in the locations shown in Fig . 6 .
I Square and start at hinge end of stair .
✎ Two nailing holes have been pre-drilled on the end above the piano hinge . Pilot holes should be drilled if lag screws are used . It is recommended that nailing holes be pre-drilled by the installer . The pivot plate mount should be shimmed and nailed through the 2 holes in the plate .
Step 5 Remove the temporary slats and 8d nails . Ref . step 2 . — 3 —