How to patch cracks in cement balcony floor

[Alan Lightstone]

Since there's lot of expertise in cement here on the forum, I thought I'd post this question about a repair I just found out that needs to be made.

My cement balcony floor has a crack near the edge / outside the railing. This floor is poured cement, over cinder block. I'm the second owner of the house. The floor must have been poured in 2007.

What is the best substance to use to fill the crack? I'm assuming that caulk won't do anything to structurally stabilize it.

Here's a couple of pictures of the crack. For reference, the paver driveway is 18 feet below the concrete floor, though it looks attached at first glance.

Crack at edge of balcony over driveway 1.jpg
Crack at edge of balcony over driveway 2.jpg

[Bill Dufour]

No expert but that will have to be cleaned out and epoxy poured in or injected. Cleaning is probably sandblast and chisel.You need to seal out water from the rebar inside the concrete. I assume salt is in the air so rust is faster.
Bill D

[Edward Weber]

I would suggest some type of concrete epoxy.
As Bill said, clean the crack thoroughly and follow the instructions.

[Cameron Wood]

Figure out why it's cracked before bothering with cosmetic repair.

Looks like there are dissimilar materials below.

Can't picture the "cement over cinder block- the wall could be block, but under the slab?

[Bill Dufour]

What happens if a big chunk falls 18 feet and lands on someones head? Individual home or condo? Check your insurance fine print.
Bill D

[Lee Schierer]

What happens if a big chunk falls 18 feet and lands on someones head? Individual home or condo? Check your insurance fine print.
Bill D

I agree with Bill. That crack could be a sign of more severe problems. Florida has had several buildings with construction issues of late. If this is an apartment building, I would notify the building inspectors.

[Sam Force]

In the second picture it looks to me like there is a crack behind the railing that appears to be connected to the issues in front of railing as well

[Lawrence Duckworth]

If this floor is poured over cinder block, then I'm going to assume that it is supported on four corners and not cantilevered. If this is the case, then a concrete overlay of epoxy or an acrylic polymer would be a good fix. I would suggest hiring a professional to do it though, they'll know how to clean and prep the crack. do a search in your area for concrete overlays , I think the one you have is called a "Cool Coat texture" ....typical for pool decks

[Alan Lightstone]

I really need to get some better pictures to post.

The floor appears to be cement with a textured coating that has lasted 16 years so far.

The ground floor outside deck is made of the same substance.

The house is supported on an absurd amount of piles. Pretty sure it’s secure. No other settling issues noted anywhere.

The balcony and in fact the whole living portion of the house is supported on a poured cement (or concrete or whatever that stuff is). Massive concrete columns on both sides of this piece where the crack is. Nothing cantilevered.

[Alan Lightstone]

It's been very hard to get anyone to do small jobs around here. I spoke to a concrete leveling company a few weeks ago regarding fixing the entry walkway to my HOA. He refused the job, and said I'll have a tough time getting anyone to pour that little concrete. Similar story with other repairman in this area. I'm thinking this isn't unique to here.

What type of company should I be looking for to fix this?

And, interesting, Lawrence, this does looks like a "Cool Coat Texture" now that I know the name of it. Thanks. Any issues painting over that? I was thinking of giving that chore to my son. The Sherwin-Williams manager thought it would be ok, but now I'm wondering.

[Walter Mooney]

Alan, this is probably something you can do yourself if you can spend some time on your knees (with some padding beneath them ). Get a scratch awl, or one of those ‘grout removal tools’ they sell at the borg, or maybe even a Dremel tool with some little grinding blades, and scratch away / clean out all the loose, crumbly stuff on the edges of the crack. Make the edges ‘crisp’ and solid. Then blow it out nice and clean, with nothing loose inside the crack. Make sure it’s completely dry, then caulk the crack with a urethane caulk, not silicone or acrylic. Only urethane. Urethane has far-better adhesion capability to concrete, and, it is paintable! So any future surface finish that’s put on the balcony will adhere to the caulking. No future finish will adhere to a silicone caulk joint.

Best of luck to you!

[Tom M King]

Look at the Sika caulking on the concrete aisle in Home Depot. It's not where the other caulking is.

[Mark Casey1]

Well I cant see your pictures because I am not a contributor, but I work in the concrete field on the west coast. From your explanation, sounds like you need something like Sikadur 32 Hi-Mod LPL or similar. Probably not getting it at Home Depot, but you should be able to get it at a local construction supply house like White Cap or something similar. Just follow the directions on the package, not hard to do and should last a very long time.

[Alan Lightstone]

Well I cant see your pictures because I am not a contributor, but I work in the concrete field on the west coast. From your explanation, sounds like you need something like Sikadur 32 Hi-Mod LPL or similar. Probably not getting it at Home Depot, but you should be able to get it at a local construction supply house like White Cap or something similar. Just follow the directions on the package, not hard to do and should last a very long time.

Very interesting, Mark. Looks like heavy-duty, high strength epoxy. I looked through the product data sheet and couldn't figure out if it is paintable. Do you know?

[Tom M King]

Maybe in smaller quantity:

https://www.amazon.com/Sikadur-2-Com...6227511&sr=8-4

Probably cheaper other places.

https://can.sika.com/content/dam/dms...-(Combo)-E.pdf

Yep. Cheaper at HD.

https://www.homedepot.com/p/Sika-Sik...E&gclsrc=aw.ds