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Upside down bolts


Original Post
t.farrell · · New York, NY · Joined Aug 2016 · Points: 60

Not entirely climbing related but I suppose there could be some applications. I wanted to put a few bolts in my ceiling (concrete) for trying out some stuff/practicing/etc.

Is there any concern with them going in purely vertical (ie, perpendicular to the ceiling)? I was thinking the weight would be on the nut and not on the bolt itself?

I know I’m not whipping on it, so it’s really not a big deal but just curious about vertical bolts and how the weight gets distributed in general. Couldn’t find anything on the internet about it but I don’t really know what to search for either. 

Brandon Fields · · Boulder · Joined Apr 2016 · Points: 385
t.farrell wrote: Not entirely climbing related but I suppose there could be some applications. I wanted to put a few bolts in my ceiling (concrete) for trying out some stuff/practicing/etc.

Is there any concern with them going in purely vertical (ie, perpendicular to the ceiling)? I was thinking the weight would be on the nut and not on the bolt itself?

I know I’m not whipping on it, so it’s really not a big deal but just curious about vertical bolts and how the weight gets distributed in general. Couldn’t find anything on the internet about it but I don’t really know what to search for either. 

This all depends on concrete quality, depth, bolt type and placement. If you place an appropriate bolt/hanger correctly in uncracked concrete, it'll hold a human body's weight long after we're dead and gone. Let us know if you need any info on how and what to place.

rocknice2 · · Montreal, Quebec · Joined Nov 2006 · Points: 3,129

You're looking for pullout (tension) strength for bolts placed in a horizontal ceiling. 
On vertical or slab walls you'd be looking at shear strength.

t.farrell · · New York, NY · Joined Aug 2016 · Points: 60

My understanding was that the pullout strength would be like grabbing the bolt itself with pliers and trying to pull it out.

I guess my concern is if it’s inverted, isn’t the hanger pulling on the nut, essentially working it’s way off the bolt?

Tradiban · · Unknown Hometown · Joined Apr 2004 · Points: 11,510
t.farrell wrote: Not entirely climbing related but I suppose there could be some applications. I wanted to put a few bolts in my ceiling (concrete) for trying out some stuff/practicing/etc.

Is there any concern with them going in purely vertical (ie, perpendicular to the ceiling)? I was thinking the weight would be on the nut and not on the bolt itself?

I know I’m not whipping on it, so it’s really not a big deal but just curious about vertical bolts and how the weight gets distributed in general. Couldn’t find anything on the internet about it but I don’t really know what to search for either. 

Depends on concrete but should be fine in anything that is at least 4in and not crumbling. I put critical shit on bolts in ceilings all the time at work, make sure they "set" correctly and torque to spec for sure. 

Brother Numsie · · AnCapistan · Joined Jan 2006 · Points: 880

I install very heavy mechanical equipment and systems anchored by drop-in anchors in concrete ceilings all the time.
Drop-ins are far inferior to the most basic expansion bolts we use in climbing.

Also, Australia has plenty of bolts so there's your answer as far as upside down integrity goes

nbrown · · WNC/Broomfield, CO · Joined Nov 2007 · Points: 6,856
Brother Numsie wrote:
Also, Australia has plenty of bolts so there's your answer as far as upside down integrity goes 

Haha, this^.


Seriouy though (to the OP) most modern anchor bolts have a higher tension (pullout) than shear strength anyway. As long as the medium you're bolting in is good you should have no problem.

The spec charts typically rate strengths using 2 or 3 different concrete densities, making it easy to figure out exactly what your range will be so long as you know what your concrete density is.
Jim Titt · · Germany · Joined Nov 2009 · Points: 490
t.farrell wrote: Not entirely climbing related but I suppose there could be some applications. I wanted to put a few bolts in my ceiling (concrete) for trying out some stuff/practicing/etc.

Is there any concern with them going in purely vertical (ie, perpendicular to the ceiling)? I was thinking the weight would be on the nut and not on the bolt itself?

I know I’m not whipping on it, so it’s really not a big deal but just curious about vertical bolts and how the weight gets distributed in general. Couldn’t find anything on the internet about it but I don’t really know what to search for either. 

The nut is of no interest (unless it falls off), it  just transfers the force to the bolt. My drop test rig is anchored vertically into a concrete ceiling along with loads of other junk like an overhead crane. Even on simple stuff like handrail posts the pull is straight out, the anchor doesn't know what is up or down just feels a force. In technical data for the bolt you just use the axial load rating.

Tradiban · · Unknown Hometown · Joined Apr 2004 · Points: 11,510
t.farrell wrote: Not entirely climbing related but I suppose there could be some applications. I wanted to put a few bolts in my ceiling (concrete) for trying out some stuff/practicing/etc.

Is there any concern with them going in purely vertical (ie, perpendicular to the ceiling)? I was thinking the weight would be on the nut and not on the bolt itself?

I know I’m not whipping on it, so it’s really not a big deal but just curious about vertical bolts and how the weight gets distributed in general. Couldn’t find anything on the internet about it but I don’t really know what to search for either. 

Also, do you live in an apt building? Not many houses have concrete ceilings, also there's different kinds of "concrete" that might not be suitable for anchors.

M Hanna · · Seattle, WA · Joined Apr 2015 · Points: 5

If you have a concrete ceiling it may be a post tensioned slab. If so, there are tensioned wire rope elements with various depths of embedment that could be damaged if you hit it with rotohammer.

Just a thought, not knowing the details. I apologize if this has been previously mentioned 

Tradiban · · Unknown Hometown · Joined Apr 2004 · Points: 11,510
M Hanna wrote: If you have a concrete ceiling it may be a post tensioned slab. If so, there are tensioned wire rope elements with various depths of embedment that could be damaged if you hit it with rotohammer.

Just a thought, not knowing the details. I apologize if this has been previously mentioned 

True! Likelyhood is low but that shit will blow hard if you hit one. Occasionally we have to xray decks for those, but only for coreing, not anchors.

M Hanna · · Seattle, WA · Joined Apr 2015 · Points: 5

At midspan between columns I’ve seen them sitting at 2-3” of cover! Construction is

Variable at best

Guideline #1: Don't be a jerk.

Fixed Hardware: Bolts & Anchors
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