Installing anchors into the bunker ceiling

[Paul Gossen]

I've got to install about a dozen anchors into the concrete ceiling of the wood shop to hang dust collection ducts. I'd like to avoid the dust and noise and hours of doing this job with a hammer drill. Does anyone in the LVL1 community have the training and equipment to use a powder actuated nail gun and would be available to volunteer an evening or weekend day for this job? 

Paul Gossen.

[Joe LaGreek]

Paul, 

 

I have the tool.  Only used it to connect some 2x4’s to my basement floor.  Would need to get the correct type of fasteners.  Not sure if there are different types of cartridges.

Could probably be available on Sunday.  These tools are loud.  Probably should be done when there are few people in the space.  Hearing and eye protection are required during use of these types of tools.

 

Also, I don’t do ladders anymore.  Will be the ground crew.   

 

Joe

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[Greg Michalski]

Do a few tests in old concrete before stocking up for the whole project.  I had a 50yr old slab that I couldn't get a single powder load to penetrate. 

[Brad Luyster]

I've also got a powder tool available. We used it to anchor the top plate for the wall when building out the space.

Greg is definitely right. Make sure to get a few different loads, too. Some penetrated perfectly, while others just spalled the concrete. I think we ended up using green loads for the ceiling, and yellow for the floor.

[Paul Gossen]

Thanks for the inputs and offers. I've arranged to borrow Brad's gun to do some tests. If the Bunker was built in the 1930s, then the concrete is close to 70 years old, so I'll buy some new masonry bits for the hammer drills, too. Sort of "belts and suspenders" approach. Definitely going with internal + external double hearing protection, safety glasses, steel toed boots for this. My plan is to do this next Monday (4 April) evening after 6pm.

[Paul Gossen]

Progress report on the powder actuated tool: 

I did one test shot into a concrete beam in the wood shop. I was shooting a 1-1/2" nail with a washer to fix a slotted angle bracket into the ceiling to attach wire hangers. Result was a spalling the concrete in a 1 inch radius all around the nail. The nail only penetrated about 1/2" and bent. 

I have no experience with this tool, so I don't know if this is a total fail or if adjusting the charge would work. Because I'm fixing an angle bracket, there is no room to attach the spall guard to the end of the tool, so concrete chips fly everywhere. I resorted to hammer drilling to anchor the minimum I needed to hang the ductwork, but still need to install about 2X the anchor points to give us some safety margin. 

I'm willing to do more tests with this tool on this concrete if someone with experience thinks it's worthwhile and gives me some guidance. Let me know by reply to this thread. 

BTW: I researched the strength of different concrete anchors. Here's the ultimate pullout strength of various anchors in 4000 psi concrete:

Blue Hawk 1/4" lag shield ..................................................550 lb

1/4" Tapcon screw, 1-1/4" deep ..........................................720 lb

Shot-fired nail, 0.145" shank, 1-1/2" deep .........................1,357 lb

3/16" Tapcon screw, 2-1/2" deep ......................................1,460 lb

1/4" wedge anchor, 1-1/8" deep ........................................1,771 lb

Red Head A7 adhesive, 3/8" threaded rod, 3-3/8" deep .... 10,980 lb