Safely covering a floor opening with a piece of plywood requires more than just laying the material over the hole, or even nailing it down. Total safety on the job means a total job of eliminating the hazard. Half a job...inadequate or incomplete jobs of covering hole hazards can result only in half, inadequate or incomplete accident prevention.
Several past jobsite accidents illustrate the point. A carpenter on a floor above calls down to a laborer to hand him a sheet of plywood. The laborer walks over to a sheet lying on the floor, picks it up, takes a step or two forward in the act of standing the plywood up, and goes sailing right down through the hole in the floor, sustaining serious and disabling injuries. Why did it happen?
Although originally nailed down with concrete nails, a small piece of plywood over the hole wasn't large enough to overlap it adequately. Traffic over it, springing the plywood, loosened the nails.
The plywood over the hole wasn't marked in any way. There was no warning of any kind on it. The person mistook it for a piece of loose material laying on the floor.
The person wasn't told about it. The laborer was not made aware of the fact that the covering of floor openings was a job procedure calculated to prevent accidents. Nor was the laborer told that such danger spots must be maintained and reported.
Anything less than total safety is no safety at all. The total safety attitude must be kept in mind when floor openings are being covered.
When covering floor openings:
1. The hole should be covered securely, with a cover big enough and rigid enough to prevent failure.
2. It should be painted, labeled or marked with a danger or warning "DO NOT REMOVE".
3. Every employee on the job should be warned about it.