FALL PROTECTION ANCHORS 1

[RR Structure]

Hi, One of our contractor suggested to install fusion roof anchors instead of the conventional fixed davit posts for fall protection. The advantage of using this anchor is the tension force in the attachment system to roof structure is not a lot as the fusion post will tip over at 1000 lbs. and will load parallel to the roof beyond 1000 lbs. you may refer to the following for a typical product. Does anyone have experience with this type of product? Did you ever install this product in any of your project?

 

[dik]

Looks neat... but, I'd be reluctant to trust my life with standing seam attachment...

Dik

 

[RR Structure]

Agreed. Also, I thought, do we need a certification of this product or a PE stamped drawings as a new technique is used to reduce the tension in the anchors and on roof structure.

 

[MotorCity]

While this widget may be able to resist a fall hazard load, the weak link is probably the supporting structure. The literature does not state what fall hazard load the device can resist, it simply says that it is engaged at a load of 1000 lb. Is this thing capable of resisting the OSHA 5000 lb fall hazard/tie off load?

 

[KootK]

Yeah, I'd be pretty worried that the connections between the standing seam and whatever supports it wouldn't be adequate. In situ load testing would be attractive.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[DETstru]

I've actually had discussions with these people.
This was years ago but from what I recall, the light gauge deck/standing seam roof installation works well but if someone falls and it is engaged, the roofing/deck is basically destroyed. You have to replace the panel afterwards.

I'm sure the person who this is saved by will be quite thankful it works but I doubt the building owner will be too happy about fixing the roof. They didn't tell us that until we spoke with a rep.

 

[RR Structure]

DETStru,
Thank you. Good information. I don't know the anchor posts need to be replaced too after it engaged each time? However, I am not sure about the 5000 #s load capacity will be achieved as OSHA requires.

 

[RR Structure]

DETStru, did you personally recommended in any of your projects?

 

[DETstru]

I can't say exactly where in the OSHA documentation it says this (again, it's been a few years) but they don't have to hit the 5000# capacity when you provide other means for energy dissipation. The spring (or whatever is in those anchors) extends the distance (and time) for deceleration, thus reducing the force on the roof/connection. These are tested assemblies that comply with other aspects of the OSHA requirements.

The 5000# rule comes into play when you have a rigid element that you're tying off to. Think your typical post welded to an embed plate on a concrete roof. That has to be designed for 5000# because it has no other means for dissipating the energy.

I did not end up recommending using those anchors. It was mostly cost related reasons. We designed a rigid element for the 5000# requirement.

I'm not saying the Miller product is bad. It's tested and I'm sure works just fine for protecting anyone tied off to it and definitely has applications where it works best (like existing structures). I suggest getting in touch with one of their reps and learning the pros/cons of their product so you can, at the very least, be informed for the client and make a good recommendation.

 

[thaidavid40]

We have used these anchorages several times before for industrial roofing and above-roof structural work. They have uniformly provided proper anchorage and protection. When attached to a seamed roof they do tend to distort the roof panels during a fall event. However, repairing the damage from one fall event is still much cheaper than the disaster of an unprotected fall. And no one gets hurt! If Miller says they are appropriate for your application, I would trust their advice.
For what it's worth,
Dave

Thaidavid