When do you need to use shoring?
OSHA in 1926 Subpart P applies to all open excavations made in the earth’s surface. Excavations are defined to include trenches.
It states that:
“Each employee in an excavation shall be protected from cave-ins by an adequate protective system designed in accordance with paragraph (b) or (c) of this section except when:
- Excavations are made entirely in stable rock; or
- Excavations are less than 5 feet (1.52 m) in depth and examination of the ground by a competent person provides no indication of a potential cave-in. (Note: 4′ Washington)
- Protective systems shall have the capacity to resist without failure all loads that are intended or could reasonably be expected to be applied or transmitted to the system.”
What that means
If you dig a ditch 5’ deep (4’ deep in Washington) then you need to slope or bench the sides, use shoring, use trench shields, and or a combination of protective systems.
The 2nd point above states:
“…and examination of the ground by a competent person provides no indication of a potential cave-in” means that if the trench is less then 5’ deep (4’ deep in Washington), and there’s a hazard that could still make the trench unsafe, then a protective system still need to be used.”
One example would be if the trench is 3.5’ deep and a welder is welding in the bottom. Because the walls of the trench are well above his body, it could be reasonable to assume dirt from the trench could still bury the worker in the event of a trench collapse.
Misconception about “Stable Rock”
Stable Rock is defined as “natural solid mineral material that can be excavated with vertical sides and will remain intact while exposed…”
A lot of people may claim that they’re digging in “stable rock”, therefore there is no need for a protective system. However, if there are cracks/ fissures, water seeping in, or if the soil is layered you are probably not working in “stable rock”.
This is where a well-trained, competent person comes in. Contact your local trench safety company to find out more.
How we can help you
Trenchman Shoring Services, Inc. is a trench safety company located in Lacey, Washington providing several shoring solutions listed above. Trenchman can train your crew in “OSHA in 1926 Subpart P” through our “Competent Person’s training”.
With over 25 years experience in trench safety, feel free to give us a call if you have any questions or need a consultation. (360) 485-6160.
Note: While Federal OSHA states that a protective system is required at 5’, other states (like Washington) may require it at 4’. Please check the standards for the state that you’re working in for the local requirements.
