The home I inspected this morning, built in 1974 did not have drywall interior walls, the panels look like they are made of fiberglass, finished like regular drywall. I have never seen it before and need help identifying. It is all walls, and ceilings in the home. This home is in Glendale, AZ. I am trying to post a photo of wall, but the “manage attachments” or attach file button is not working for me. I know that a picture will make it easier to identify.
Could they be concrete panels (cement board) like bathrooms ?
Go to advanced at bottom which is right of the save button first.
Bob, no they aren’t a cement product. I sent a picture to Marcel to post it for me. I am not sure why my computer won’t allow me to post a photo here, I’ve posted photos many times before.
Thanks Marcel, do you know what it is?
Can’t say I recognize that product from the 70’s. 
Dale, have you ever seen them used on interior walls in residential homes? All the walls?
The owner was probably a distributor, I see the panels in old commercial buildings, restrooms, kitchens, break-rooms, etc.
They cost big bucks.
Hmmmm reminds me of green house filon panels.
Stainless steel being expensive they would install the Fiberglass Board at wet areas rather than stainless steel. Waterproof and easy to clean.
The owner had to be a distributor or something, or one of his buddies.
PS. Maybe someone installed the reinforced fiberglass panelboards because it was a rental home, who knows.
I wouldn’t want to try and put my fist through one.
Yes Dale, those are Fiberglass Rated Panels, I have used those frequently in bathrooms and kitchens. 1/8" thick. To get the fire rating, they are installed with buttons and glue.
But that is not what the picture is. Never came across that one.
I tend to agree with Marcel. FRP panels are just a veneer (1/8" thick) that is glued onto the substrate, usually drywall. It has no structural qualities at all, but it does have an orange peel texture. The OP photo looks different.
I see FRP’s installed in many new construction restaurants (IHOP)
Now that I think of it I also found those thick FRPs in a sound recording studio with insulation on both sides, the FRP was in the center of the two layers of insulation finished with 1/2 sheetrock.
It seems a matter of renovation done on the previously poorly built wall against the weak structure of the present wall so by doing this the present wall is dangerous condition because it has no inner strength to support the complete structure the only safe option would be demolishing the present wall and erecting a new wall on that place with the help of some support beams.
View same scenario.