Fold down attic access stairs are often poorly installed. It is likely that if your home was built before 2006, the fold-down stairs to the attic are improperly installed. It is rare but I have personally witnessed two of the assemblies fall with men climbing on them. Fortunately the men were not hurt but they could have been.
In recent years manufacturers of these units have been affixing installation instructions on the ladder in a manner that is easy for anyone to see. Unfortunately these are sometimes removed after installation.
Below is a statement that I use whenever I find folding stairs that are not properly installed.
"Attic access ladders should be fastened in place with 16d nails or 3" lag bolts. There should be at least 3 on each side and where metal nail plates are provided one fastener should be in each metal plate. The ladder frame should be shimmed so there is no gap between it and the rough opening where it is fastened. There should be no gaps in the ladder rails and nuts and bolts in the hinges need to be secure."
This statement was developed after reading installation instructions from several different manufacturers. They don’t all use the same wording and some are more specific than others. Below is a photo of one such label.
The main things to keep in mind about an attic ladder installation are the fastener type & location and the length of the ladder side rails. The fasteners need to have enough shear strength to hold the ladder securely in the rough opening. Most manufacturers specify either 16d nails or 3” lag screws. Many specifically disallow wood screws or deck screws. I’ve seen them mounted with finish nails, drywall screws and staples. Most of these fasteners do not have the shear strength to hold the ladder in place.
Shims should be installed between the ladder unit and the rough opening so there is no space in that area. This adds to the security of the unit when fastened in place. Below are some photos I took at one location where multiple mistakes were made during the installation of the attic access ladder.