Evaluating an Existing Canopy Anchor

[kipfoot]

What would be your approach to evaluating an existing eye-bolt connection where there was once a canopy on a 100 year old building? The original is long gone and we'll be attaching a new canopy in its place. My thought has been that I'll be asking less of it than it was intended for and therefore...it's fine.

Lately I've had the notion that we should apply a test load to the anchor to be sure that we can rely on it. But, then my question is: What would be the mechanism of testing that gives me confidence and doesn't damage the existing assembly? ASTM number? or just strap a come-along with a force gauge?

The condition of the masonry overall in the building is sound, and the mortar is solid in the area of the anchors. There's pitting on the surface of the metal, but I don't have an evident reason to believe it's deteriorated inside the wall. I do not have access to dig and verify the anchor from the inside (it's decorative plaster work) so I don't know what the anchor actually is. The round bar that was used is 1" diameter (presumably iron). The load in the diagonal that will connect to it is about 1500 lbs (1160 horiz, 970 vert)

 

[bugbus]

Looks very crumbly. If replacement is an option, you could potentially cut off the existing eyebolt, drill out the rest of the anchor and then chemset in in a replacement eyebolt. At least that way you can keep the decorative element. Paint the new eyebolt black and you probably couldn't tell the difference.

 

[SWComposites]

Seems like you have two choices:
- tear it all out and completely replace
- perform a proof load test to 3-5 times the max load

That lug looks ugly, and I wouldn’t sign off on any strength capability without a test.

 

[Tomfh]

As it is, with corrosion and what not, I’d want a 4x proof load.

 

[wrantler]

Is that cast iron? or wrought iron?

Can you salvage the piece and cut off the eye bolt portion. And add a new anchor that you design. So it looks old and original but the new eye bolt is new and surrounded by the old shell.

Goodluck..

 

[bones206]

A load test seems appropriate for sure, but I would still have a hard time relying on it without any redundancy. Any way you can include some new discrete structural elements to provide some redundancy in case there’s a brittle eyebolt failure?

 

[dik]

Can you do any examination of the anchorage... xray, ultrasonic, or whatever is available... I'm not certain... Ron or JAE might have an idea. Do you know what the material is of if it's corroded beyond? If all is sound, I would be looking at a proof load of approx 2 or maybe 3, but not much higher for fear of damaging the structure. 4 or 5 would be out of the question. The test load should be applied in the fashion the connection would be loaded.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[ALK2415]

You could penetrate through the exterior wall, from face to face(if possible). any And reinstall your anchorage Eye-bolt (from reliable manufacturer).
even with your capable hand calculations still you need to pretest them to make sure they will have some additional margins of safety. In case your 100 years masonry/concrete wall will deteriorate (due to moisture and additional pullout force)

 

[JAE]

I'd try to go with what bones206 suggests - an alternative load path to support the canopy (maybe a second diagonal rod to a new anchor into the masonry wall) and have the rod connecting to your old eye bolt just be, uh, eye candy.

 

[KootK]

My thought has been that I'll be asking less of it than it was intended for and therefore...it's fine.

How much less do you figure?

 

[calvinandhobbes10]

Assuming you’ve got a canopy a few feet below this decorative eyebolt, with diagonal rods or cables connecting the eye to canopy corners or edges—- did you consider doing this the way I’ve seen many modern canopies designed, where the diagonals (and therefore your eyebolt) are ignored for design? Especially if uplift controls and those ties would have to be wide enough not to buckle, which no doubt would be prohibitively ugly.

I suggest making the canopy work without these eyebolts (can you through-bolt the masonry wall in concealed places to make moment connections?) and then allowing them to remain for looks.

 

[kipfoot]

Thanks all for your insight and suggestions.

I'm going with the consensus that it needs to be tested, and I'll look for ways to add redundancy. I can add some fixity where the canopy connects to the building, which will reduce the demand somewhat, but I don't think it will be enough to make the diagonal purely decorative.

If we test it and the friggin thing pulls out of the wall I'll be sure to follow up with pictures.

How much less do you figure?

maybe 15-20%. That's based on a presumption that, being hung from chains, it was ballasted. I think the geometry will be roughly the same as the original.

 

[kipfoot]

which no doubt would be prohibitively ugly.

I'm going to use a pipe that'll be as slender as I can make it, and hopefully not too ugly.

 

[dik]

For testing, you may want to use hydraulic load tester. When failure occurs, the load reduces very quickly

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[jerseyshore]

I feel like the liability is very high for something like this if there ever was an issue, load test or not. If I specify a load test it's to back up a book value or calculation.

In reality it's been there for 100 years and maybe it lasts another 100, I just know it's not going to be because I put my seal on it.

In a couple of months when you get a bad snow, you'll want to have a Hilti anchor in there and a decorative bracket on top.