Unknown type of wall board that I'm struggling to identify. Can anyone help identify it?

Question

This wall board is in a bathroom, The house was built in the early 50's, but I'm not sure when the bathroom was put in.

oddly enough, the studs are 4' apart, but it's still sturdy, and the actual wallboard is of an unknown material- nothing I've seen before. It broke the tips off my razorblades, and I still haven't been able to get even one little thin cut out. I was able to chip off a small 1"x1cm sliver and it looks like a dense cardboard/cork/wood material, but is unlike anything else I've seen in construction. I may try to hammer through it, but there is electrical behind there, and I was hoping to figure out what I was up against before I destroy it!

Does anyone know what this could be? I expected greenboard- maybe even cement board, but I have no idea what this is!

Thanks!

Answer 1

Sure sounds like the concrete hardy board.

Answer 2

This may be what was called "Beaver Board". It is about 1/4" thick and looks like "Masonite". It was used in the 50's as an interior wallboard.

We ran into it on a couple of remodeling jobs. It was primarily used to build subdivisions for the post WW 2 soldiers coming back home. If it was in your house, chances are other homes around you also have it.

It's pretty tough that's why some homes were framed with wider stud spacing. They were trying to keep the cost down on these homes so they could sell them through the G.I. loans to these soldiers.

Answer 3

If it was built in the 50's there is a chance it is asbestos wall board.  asbestos wall board was used mainly around kitchens, and for home exteriors, but I have seen it used throughout entire homes.  

Answer 4

Could it possibly be plaster lath? Homes of that age often have that on them. It consists of laths nailed to the studs and covered with a grout type of plaster it is very hard and difficult to repair. It is extremely hard and near impossible to cut. You have a few options you can go over it with 3/8Th's wall board or tear it out and put up new. I highly doubt that it is asbestos as it should have been listed in your home disclosure.