The red lines on the left side indicate the knee wall.
Attic support structure.
Depending on the roof covering material either horizontal laths battens or purlins are fixed to the rafters.
They are designed to carry only the weight of the drywall or plaster depending on the age of your home.
Or boards plywood or oriented strand board form the roof deck also called the sheeting or sheathing to support the roof covering.
As long as they are not damaged the joists should be strong enough to allow you to move around in the attic for an inspection and to provide storage for typical boxed items.
Attic and roof structure inspection your home check.
Typically ceiling joists are 2 6 or 2 8.
Addition of engineered i joists.
The floor structure of an attic is also the framing for the ceiling beneath it.
Collar tie used for adding additional support to attic roof supports.
More times than not the floor structure of an existing attic is actually a ceiling joist.
This photo indicates a properly installed knee wall in a attic for additional support to roof structure.
How to get a loft conversion yell fix that scary roof popping noise elements in the loft roof structure feasible is it to remodel your attic loft conversion.
This is made up of ceiling joists typically 2x6 or larger boards.