wood fiber-cement roofing? 1

[psustruct]

I was on a job site today -an old warehouse- where we thought concrete was spalling on the roof. What we thought was concrete was actually a wood chip and cement mix. What we thought was rebar, well... it wasn't. I'm not sure what it was as I could not get close enough to touch it. There was wire spaced about 3 inches on center and it ran perpindicular to the bar. It was kinda like a mesh.

I'm not familiar with this construction. Is it structural or just a form of insulation?

 

[psustruct]

Here's another photo (taken from the floor).

 

[Ron]

It is a cast-in-place form of insulation, similar to cast-in-place gypsum, and pre-dating Tectum panels.

It looks like it has lost most of its integrity. Be careful walking on that roof, although the mesh provides some protection from falling through.

 

[psustruct]

Thanks, Ron. Do you think there is anything else structurally holding this roof up? My brain tells me there has got to be, but I really don't know.

 

[Ron]

Not necessarily. These cast-in-place systems were popular in the late 40's, 50's and 60's. Most were gypsum based, but some were portland cement with a variety of insulative aggregates used.

 

[sbouvia]

This could be a metropolitan type floor system. How old is the building? There is a paper by Donald Friedman that you can check out and see if this is what you have.

http://www.apti.org/publications/PP-archive/Friedman-PPs.pdf

Hope that helps.