Technical Report – Cracking, Rising Damp, Structural Integrity

careface cracks concrete

Welcome to the darker side of decorative flooring

I want to cover a few topics here in a very blunt and direct nature, offering explanations on why these things occur and where it leaves us as professional installers with often, a very tough decision to make.

First I’ll cover cracking and the patching “repairs” of said cracks. Followed by a few things that only pop up from time to time, but need a little technical coverage because on the rare occasion when they do pop up, they can be confusing and hard to manage.

Maybe other professionals in the industry might be able to use this blog format to pinpoint what is happening on their project, or at least I can direct any clients of mine towards this blog to review some technical information from a 20+ year veteran.

So without further adieu and a 0% blood alcohol reading, lets get started.

Patching Repairing of Cracking

To be fair, this topic is such a blatant “logically makes sense” issue, it really does suprise me on the odd occasion when someone doesn’t understand that the decorative overlay and patching that has been applied, doesn’t stop the concrete underneath moving and the crack opening up again.

I actually don’t even know if I need to go into further detail other than that…..The Majority of people will get the point. But, for the those special few who don’t, lets talk more.

Cracking in concrete is considered by both amatuer installers and double decade structural engineers as normal and typical and nothing done during the installation of said concrete is to prevent cracking. On the contrary, everything that is done is to “control” cracking. Where, how far, what angle, what stress levels etc etc. From steel reinforcing holding the crack together, to control joints specially put in to make the concrete crack where we want it to….cracking to concrete is like bubbles in your champagne, you don’t get one without the other.

Legally from the standpoint of Australian Standards, if the control measures installed into the concrete are working effectively on the crack that has appeared, then the crack is to be considered “non structural” and not a problem. In turn, if the control measures are not working effectively, it is to be considered “structural” and in need of rectification. Either way, the warranty provided for the cracks in your concrete, is supplied over a 7 year basis by the contractor who installed your concrete.

Crack Repairs Concrete Resurfacing
Concrete Refurb Grind and Resurface Wellington Point
Epoxy Flake Floor Ormeau
Epoxy Flake Floor Ormeau

Filling Your Crack - Pun Totally Intended

THIS IS NOT A REPAIR!!!! (big letters in bold with exclamations for emphasis!)

This system of what we do is specifically called “patching”. It is common in the industry and quite normal from home domestic jobs to large commercial sites. Yes, you will have one or more of your chosen contractors come out to quote with a droopy mouth and a few missing teeth and tell you they’ll repair your crack and you won’t see it agian, but that is an absolute load of shit and you should just smile while you subcontiously tell yourself to run for the hills.


Simple huh? Someone like myself, makes this one of the main talking points of your project during our initial consultations. Ask any of the quotes we do. I make this topic so blatantly obvious to the client, that no confusion can be present.

“What I am doing, is patching and filling your crack with epoxy and silica sand, the strongest method I have available to do my absolute best to try and have that crack not return. BUT, you should expect that crack to return, because once you start driving your 2 ton car over the concrete again, it will supress the ground underneath, cause the concrete to flex and tension again, which will reinstate the inital reason why your concrete cracked in the first place. The good news is, WHEN your crack returns, it will look somewhat like the picture above, a relatively hairline crack that is no worse than it already was, more often than not better.”

I can and might some day, go into a hell of a lot more technical detail on cracking, but I think this part of the blog at least describes things in enough detail so the few who can’t see anything with reasoning, might have a second opion to go through.

PS: Contractors. Stop calling these things fucking repairs. Be professionals and speak from experience. I guarantee very few of your “crack repairs” remained hidden for more than 6 months.

Rising Damp - Lack of Vapour Barrier

This one here is very uncommon. In the last 20 odd years, I think I’ve come across 2-3 of my own works that have encounted this, along with another contractor sending me some photos asking me what it was, which I was happy to explain to him the details, coming directly from experience.

This is called “Rising Damp”. I just had my latest one pop up from a lovely client that we completed some work for last year, which again, due to having dealt with this before, the cause was very straight forward.

Basically, when concrete is installed that is going to be tiled or basically be an internal floor to have coverings, as a concreter, the engineering dictates that a vapour barrier be used (Visqueen). This prevents rising damp which will in turn pop your tiles off over time, and in this case with resurfacing products, leave the sealer looking a little cloudy in the areas that it is rising.

Unfortunately, not being in control of the inital installation for the concrete, we have absolutely no idea during your surface refurb if this is going to occur or not. This latest one, has shown it’s face after we have just received 500+mm of rain in the last wet season down pour, and has primarily occured on the outer areas of the patio, along with control joint and crack patches where moisture can rise more easily from the sloppy ground under neath.

Damp Rising Concrete Resurfacing
Rising Damp Sealer

Here is another example sent through from another contractor. They applied a clear sealer to coloured concrete roughly 6 months ago, basically now again after the heavy down pours, the rising damp is starting to cloud the sealer on top appearing to change the colour of the concrete.

Unfortunately with this problem, there is no real fix. The only method of work available, is to firstly try and use solvent to dilute the sealer on top, hoping that the moisture in the sealer will be removed. If / when this fails (rarely does the job), a choice needs to be made to either redo the area in question, or leave it as is because, through no fault to anyone it will only keep occuring whenever heavy rains are received through outside factors that your resurfacing installer cannot control.

I know we’re always looking for someone to blame in modern society, but sometimes, accepting that shit happens, is the only thing to do when no one is to blame.

This leads me to my final topic of discussions…….

Risk VS Reward

There is no point making something look amazing if it’s not going to hold together. – Me (all the time).

We do some awesome designs and quality of work. I know I say that about myelf being a little pretentious, but I am just ask quick to point out a negative as I am to verbally uplift my own workmanship.

We do however run into tough decisions from time to time that clients sometimes don’t fully understand. There is a point where we need to leave well enough alone. To fiddle, is to lessen the structural integrity of the product, and lessing that integrity will lead to problems in the future that shouldn’t need to arrise. I’m not talking about the warranty periods that we’re responsible for, I’m talking about the long term integrity of your product install.

Take for instance the cracking issue, there is nothing that can be done to stop concrete from cracking, apart from removing the actual concrete and replacing it with new concrete…..which will most likely crack somewhere else then….because….it’s concrete ffs.

Rising damp. We hate to see this as much as you do. It sucks. All that hard work put in. But to play with the surface to try and rectify a small colour clouding issue, and run the risk of having your product not last 10 – 15 years like it should. To try and fix something that is just going to come back again next time it rains…it’s just madness.

If something does need to be done, there is a limit to how much can be done. Scuff grinding and re-coating a section that was showing an obvious miscolouration, is sometimes worth the effort in the attempt to bend over backwards to keep a customer happy. Re-doing that same process a second time to the same concrete, is most often not worth the risk for the reward that will be achieved, as further degredation to the product is only going to bring forward failures at a later date for the client.

Our goal should be giving our clients a structurally strong, hard wearing coating to their concrete that is intended to last 10-15 years at least with simple maintenance, and then worrying how pretty it looks.

If 95% of that floor looks great with 100% structural integrity, the job is complete. Perfection lies in more important areas than a shade of colour from a certain angle.

Sometimes, a stand needs to be made to ensure the client has a long lasting finish, even in the face of criticism from them.

After all, there is no point making something look amazing if i’ts not going to hold together.

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