Steel or Zinc Anchors

[ill]

It seems that there are not many ppl in the trade, that I'm aware of in my circle, that differentiate between steel and zinc anchors when used to mount equipment to ceilings and walls indoors. I'm talking from a safety standpoint. Steel anchors have a higher melting point than zinc anchors. With the use of zinc anchors, if a fire occurs that yields a high temperature, the equipment secured to ceilings and walls could drop out and injure ppl exiting the premise or fire fighters entering the premise.

I just had a disagreement with a fellow Local 3 member over this. He suggested that my view was incorrect and that zinc anchors were safe to install on ceilings to support equipment. He based his opinion on the fact that all the shops he worked in used Powers Doubles in the ceiling to support equipment. Doubles are produced using zinc. I find that the only anchors to carry a UL approval are those that use steel. I would attribute this to a higher melting point.

I would like to read your thoughts.

 

[bphgravity]

This is an interesting question, however I am not sure this is a pressing issue?

Do you have any data or reseach indicating the events you describe occuring and injuring persons?

Not to get off subject, but I feel much more can be done to prevent fire or at least exposure to fire verses finding ways to protect persons after the fire has already occured.

 

[Bob NH]

If the fire is hot enough to melt zinc (more than 700F), it will destroy any wood or sheet rock, and will kill anyone in the vicinity. A fixture falling on your head will be the least of your problems.

The problem with zinc is that it has much lower strength than steel, and is usually used in cast parts which tend to be brittle and fail without warning when overloaded. Look at the difference between steel and zinc couplings for EMT.

 

[thinfool]

This won't help much, but when I lived and worked in NYC we were still using Ackermans (lead anchors).

Later someone told me that they were illegal on the West Coast due to seismic issues. At the time, Phillips RedHeads were the steel anchor of choice.

I don't know how NYC views anchors and seismic issues.

 

[tom baker]

What I see most commonly is a steel expansion anchor, or an epoxy anchor. I mostly use the epoxy type any more, as commonly fastening into concrete block , this anchor is the best for block.

 

[sparky252]

When you refer to zinc, you are not meaning lead are you. Around here, we use drop-ins or leads, usually the former.

Epoxy ones? Got a website link or photo. I am drilling into crumbly solid concrete ceiling. I recently was trying to get used to the Red Head Hammer-on anchors cause I had limited tools/material at current job site. I don't like them yet, for installing or holdong power. Any tricks?

I borrowed some of the plumbers 3/8"s steel drop-ins...same reason. Guess I need to get a material list so I can start the process of getting them into my jobsite...paperwork, authorization, etc. Or, maybe I'll just use that roll of duct tape.

 

[infinity]

When you refer to zinc, you are not meaning lead are you. Around here, we use drop-ins or leads, usually the former.

Epoxy ones? Got a website link or photo. I am drilling into crumbly solid concrete ceiling. I recently was trying to get used to the Red Head Hammer-on anchors cause I had limited tools/material at current job site. I don't like them yet, for installing or holdong power. Any tricks?

I borrowed some of the plumbers 3/8"s steel drop-ins...same reason. Guess I need to get a material list so I can start the process of getting them into my jobsite...paperwork, authorization, etc. Or, maybe I'll just use that roll of duct tape.

Many of the older buildings in NYC have cinder fill concrete. This is a thin layer of concrete covered with cinder fill and a layer of concret over the fill like a sandwich. The only anchors that will hold in this junk are the double expansion type. If you're having trouble with them holding, try drilling the hole 1/8" smaller than required and lightly tap the anchor in with a hammer.

Here's an example of a chemical anchor:

The link:

http://www.us.hilti.com/holus/modules/prcat/prca_navigation.jsp?OID=-12287

 

[sparky252]

Thanks Infinity for link, photo and explanation. I never heard of or saw that before. If I had one here i'd tear that wrapper off to see what's inside. Am I right to understand it already containes some hardware or just hardware ready. (made sense to me.)

Hey, speaking of concrete hardware...I got asked a question by the GC Rep. It's at my first job I am running and I have been getting the distinct impression this guy knows as little as I. He asked, "How'd you get that threaded rod stuck into the ceiling?" Good thing my head was near the ceiling so he could not see my face & expression. He was looking at my simple unistrut/threaded rod trapeze rack. I used fancy stuff, I guess.....3/8" steel drop-ins!!!! Epozy/chemical anchors would probably blow him away.

He's not from around this part of the state, maybe he came out from under a rock.

 

[H.L.]

A contractor buddy of mine has used the Hilti epoxy for 25' light pole anchor bolts... He swears by them.

H.L.