Mat Footing: OSHA req'd rebar spacing?

[FoxSE14]

Is anyone aware of an OSHA requirement for the spacing of top reinforcing bars in a mat footing (say 3-4 foot thick)?

I'm seeing a detail where there's 6x6 WWF being placed atop the typical reinforcing bars (12" o.c. e.w.). I'm told the reason for this is so that the rodmen don't injure themselves if they should misstep while walking across the top mat. While I agree that this might be a prudent thing to do, a value engineering situation might make deletion of the mesh a reality. Thoughts?

 

[FoxSE14]

I should say that I'm thinking this is not required for our particular footing depth. If for some reason our mat was greater than 6' deep (standard height req. fall protection per OSHA), this 6x6 mesh might be conform to the "safety net systems" provisions. Thoughts? Thanks.

 

[cvg]

OSHA has no such requirement, however the OSHA requirement in general is to protect workers from impaling themselves on vertical bars and secondarily, from breaking an ankle / tripping on the rebar.

see CFR 1926.701 (b)

 

[Ron]

Agree with cvg....OSHA doesn't dictate structural design except for capacity of fixtures for fall protection.

 

[chicopee]

OSHA does not dictate any design, although, this may be argued after the Jahn foundry explosion in Springfield, MA; reconstruction of the casting area was an OSHA approved design as the rumor goes.

 

[concretemasonry]

It is strictly a safety problem since there many not be a sufficient space for workman to use safely.

Some wire 6" apart can be a problem on a 4' thick pour if the workers cannot work and do the job. A 240# placer standing on two wires has little stability even if he wear size 14 boots.

If it is a safety problem and the plans are drawn that way, the contractor has to provide the safe access to and around the work area. - Hopefully, the cost will be in the bid price. Usually plywood sections are used and re-used, but that introduces other problems.

Engineer and international traveler interested in construction techniques, problems and proper design.

 

[DayRooster]

Safety by design is currently not enforced by government agencies such as OSHA. Though many cutting-edge engineers & contractors have recognized benefits of including safety by design within their scope. Six inch maximum spacing for reinforcing is a common practice exercised by many engineers. For further insight about safety by design I will refer you to the guru Mike Toole at

http://www.designforconstructionsafety.org/