Indication of Roof Weight :

The indications available of roof weight are coming down over mine opening can be sense by -

1. The prop, when tapped with a stick, produces a dull and drummy sound.

2. The lid over the top of the prop bends.

3. The prop buckles in the middle or at weaker points in its length.

4. If the floor is soft, the prop may penetrate it.

5. There may be rumbling sound in the goaf.

6. Booming sound of roof movement increases.

7. Heaving of floor as well creeping of roof is noticed.