Make raycast ignore a layer?

I have been looking about the forums but none of the other answers seem to be any help. I created a layer that I want one of my raycasts to ignore.

 private int layerMask = 1 << 9;
Ray pointerRaycast = new Ray(transform.position, transform.forward);
            RaycastHit pointerCollidedWith;
            var rayHit = Physics.Raycast(pointerRaycast, out pointerCollidedWith, layerMask);

            if (pointerCollidedWith.transform.tag != "Wall" && ObjectProperties.WallObject == false)
            {
              
                lastInstantiated.transform.position = new Vector3(pointerCollidedWith.point.x, pointerCollidedWith.point.y, pointerCollidedWith.point.z);
            } else if(pointerCollidedWith.transform.tag != "Floor" && ObjectProperties.WallObject == true)
            {
                
                lastInstantiated.transform.position = new Vector3(pointerCollidedWith.point.x, pointerCollidedWith.point.y, pointerCollidedWith.point.z);
            }
            {
                
            }

For some reason this code isn’t doing anything?

use the operator ~ if you want the mask to ignore a specific layer.

private int layerMask = ~(1 << 9);