We are currently doing a project that modernizes the fireplace. The original fireplace has a typical look with mantle just above the opening, bricks below and in the hearth.
The mantle was removed and the entire wall smoothed with Type X drywall. The opening of the fireplace is made smaller with a "retaining wall" made of Type X drywall as well. The inside of the fireplace will be filled with concrete, which will raise the floor of the fireplace to the height of the "retaining wall". We will pour fireglass in there to complete the look.
My question is whether Type X drywall at those places are up to code? Thanks for any advice.