Granite Crack Repair

[Deadblow]

See the attached picture. This is an approximately 36" long crack in a 6" thick vertical piece of granite. Can anyone suggest an appropriate epoxy to repair it? Whatever product that I end up specifying, will be exposed to temperatures in the winter of around -10 degrees below zero Fahrenheit to about 110 degrees Fahrenheit in the summer. I am leaning toward grinding the crack with a chaser diamond blade on an angle grinder and caulking it to allow the crack to move. The owner wants an epoxied crack and wants the crack to be hard to detect.

We believe that ice caused the stone to crack. The crack was not there for 70 years.

Thanks for any suggestions!

EIT

 

[JAE]

What am I seeing near the bottom of the photo where the granite is spalled away?
Is the granite a thin veneer on some other material?



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[Deadblow]

@JAE,

There is a capstone on top of a wall at the bottom of the photo. This cap was removed and is setting at the bottom left of the photo. The granite piece that is cracked, does have a structural concrete support behind it. I included another picture for reference.

EIT

 

[rb1957]

that looks to me like a recess, for a tapered cap (of a railing/balustrade) ? odd that the crack seems to make a bee-line for the edge of the recess ...

another day in paradise, or is paradise one day closer ?

 

[oldestguy]

Almost anything will make it more visible or even enlarge it. I'd contact the type of business that works with decorative stone or even grave stone suppliers, since cemeteries may have to deal with vandalism, etc. and may have methods to reduce visibility.

 

[IFRs]

Flexible grout with granite powder may be your best choice.

 

[rb1957]

but what we're (I'm?) seeing doesn't look to be a 6" thick piece ... that recess looks much less than that ?

another day in paradise, or is paradise one day closer ?

 

[hokie66]

If the intent is to make it look pretty, and if you can find some stone to match, it would be better to cut that piece out and replace it. Make the new joint straight up from the internal corner which caused the crack.

 

[Ron]

Agree with hokie66. Looks like a relatively thin veneer. Most any granite countertop guy could do that!

 

[Deadblow]

Thank you for all your suggestions. I agree with your thoughts. I personally measured the piece that is cracked and it is indeed 6" thick (government building). The coped piece resting on top of it is 5.5" thick. The vertical pieces on the front and rear of the retaining wall in the bottom of the picture are each 4" thick. I'm still investigating our choices. My concern is that the epoxy that I find used for countertop repairs is not UV resistant or designed for use in freezing temperatures. Also, we do not want to polish the crack after the repair, or we will have a piece that looks brand new and literally thousands of pieces that look 70 years old. It sounds like I might be trying for the impossible, so I appreciate your input. I will contact some grave stone places and if the repair we go with looks ok, I will try to post a picture or two of what we decide.

EIT

 

[Tmoose]

I'd go for the bling.

http://newtonwellesleydentalpartners.org/wp-content/uploads/2016/05/Project1-3.png

 

[OldBldgGuy]

Deadblow: I have no idea where you are but there are dozens (hundreds?) of companies in Canada & the US that specialize in the repair of historic masonry. No one is going to make that crack disappear, but it can be repaired using various methods with greater & lesser degrees of success. If the quarry is still open, hokie66 is right, get some stone & make a new piece with a logical joint. If you can't find the stone, find some stone conservators (google is a great tool) and ask for references and examples of previous work; their results will amaze you. There's not much point in trying to specify the materials for repair yourself without any experience in it, better to invite the expert trades to propose their solution. If you want to get a bit of background knowledge,

https://www.nps.gov/tps/how-to-preserve/briefs.htm

 

[dik]

New stone colour and grain will likely be off... and, most epoxies tend to 'dull' when exposed to sunlight, even with UV inhibitors. Contact with a restoration specialist is likely the only way to go and they may source a granite of similar grain and colour. Patching will likely make matters worse.

Any idea of what caused the cracking and has that been remedied? Also with restoration stuff, I've seen repairs in a contrasting material to show that the areas have been repaired.

Dik

 

[OldBldgGuy]

As Dik says, make sure you know what caused the crack & are sure that the cause has been dealt with. Otherwise the repair will recrack at best and cause new cracks somewhere else at worst. A good stone conservator can repair the chip at the upper right with a dutchman, too.