CIP Floor on "Fabric" and Steel Joist
CIP Floor on "Fabric" and Steel Joist
(OP)
I have run across a structural floor system I have not seen before and I'm looking for design information. I have the architectural drawings dated 1953, but no structural drawings. The system is composed of 10" deep "light" steel joist labeled #102SJ with what looks like a light gage steel mesh over the top, then a fabric of some type, on which is poured a 2-1/2" thick normal concrete mix for the attic floor (See attached photo).
The system is used throughout the building, but in the area of the photo there seems to be much more deflection of the fabric. I'm trying to determine if this is normal or if the area needs to be reinforced. There have been no noticeable problems during the life of the building - so far.
Anyone know what system this is and where I can get design information or load tables?
The system is used throughout the building, but in the area of the photo there seems to be much more deflection of the fabric. I'm trying to determine if this is normal or if the area needs to be reinforced. There have been no noticeable problems during the life of the building - so far.
Anyone know what system this is and where I can get design information or load tables?






RE: CIP Floor on "Fabric" and Steel Joist
I have seen similar systems with something like an expanded metal lath and some paper. It always sags noticeably, but not quite as much as your picture shows. The systems I have seen are many many decades old and survived office/restaurant/retail use. I have always left them alone if the system shows no signs of distress. I will take measurements on the joists (I have not run across the type of web yours have) to get a feel for their capacity, but I tend to leave the slab alone.
I have not references on their design.
RE: CIP Floor on "Fabric" and Steel Joist