Shrinkage cracks getting worse

[Fixnfly]

I'm so disgusted I don't know where to start,

My garage was built back in September of 2012, Slab is about 16 months old.
I started to notice some cracks in the spring last year. I've heard "concrete cracks" plenty of times and accepted the fact that my garage floor was ugly. the last few weeks here in Pa have been very cold, down to -10 at times and I've noticed the cracks in the floor have opened up some. Some cracks have gotten longer. Some have gotten wider. It seems that the worst areas are near the center of the garage near the useless drain.
So,
when should I be worried and what can I do about it?






These pics show the pattern well...

 

[radrush]

When the concrete was placed, what did you (or the contractor) do to cure it after the finishing was complete?

 

[Fixnfly]

When the concrete was placed, what did you (or the contractor) do to cure it after the finishing was complete?

Nothing. At the time I did not know any better but after reading this forum I learned I should have kept it wet. Contractor is a *****.

 

[LegacyIndustrial]

Once it's done you have many choices to hide them, epoxy, tile, etc...

 

[bczygan]

Unless he is willing, or you have his money or are willing to go to court and have a great contract, you are on your own.

Why the broom finish inside?

 

[Falcon67]

First pic is "not too bad, probably normal" looking. The second where the floor has moved near the drain is worrisome to me. Crack is one thing, shift in level is another. Whats with the colors along the cracks - moisture or some attempt at a sealer? Not an expert on concrete, but I can tell you I had a few that formed after the cure. Not surprising since the slab stayed about 130F in the day during the first 30 days and I only had a weekend after the pour to keep water on it. The key here is that they haven't changed in 3 years. If yours are changing, things are moving around for one reason or another. Maybe ground frost is moving the outer edges?

 

[Fixnfly]

Unless he is willing, or you have his money or are willing to go to court and have a great contract, you are on your own.

Why the broom finish inside?

I'm pretty much on my own, "warranty " was for one year and has expired.
I really don't want to deal with the contractor again. Everything with him was an argument and I think this time I might end up grabbing him by the neck.
The broom finish was not my idea.

 

[Fixnfly]

First pic is "not too bad, probably normal" looking. The second where the floor has moved near the drain is worrisome to me. Crack is one thing, shift in level is another. Whats with the colors along the cracks - moisture or some attempt at a sealer?

Back when the cracks were small, I sealed them to keep out water that could freeze and make things worse. No moisture problems.

The floor has high spots which may be why the cracks look uneven.

 

[Fixnfly]

Once it's done you have many choices to hide them, epoxy, tile, etc...

I really don't think any of your products can hide this.

 

[Mpbsr]

There are tiles like ie: Racedeck that will hide these.

 

[ConCretin]

fixnfly, I'm sorry you have to deal with this situation but you're not the first and I suspect you won't be the last. The good news is that it's not necessarily a fatal situation.

Your floor obviously has some shrinkage cracks that are opening up as the temp drops and the concrete contracts further. Your cracks are more prevalent than I'd like to see and do raise concerns about the overall quality of the installation but I've seen worse.

With that said, if you have a good sub grade and/or properly positioned steel reinforcing, the cracks are primarily aesthetic and won't adversely affect the serviceability of the floor.

It's virtually impossible to 'repair' shrinkage cracks but you can successfully cover them with epoxy, tile or a Race Deck type product.

An extra benefit of a floor covering would be to cover up that horrible broom finish. Really? Who does that? Wait, I'll answer that...... a hack.

 

[Rookie2]

That's a shame man, I would want to go postal on that contractor. I did all the prep work on my 40x60 and ended up with one 18" crack into a trough drain because i left the heat up too high one day. I've learned to go and look at jobs done by contractors if i want a bid from them on work.

 

[volleyball]

I would not cover it, it is only going to get worse. Just plan on when you are going to replace it. I laid near 200 sf of broken bags of concrete for an outside pad and it looks much better than your garage.
I think that the base was not prepped correctly. And the only way to fix it is to remove it and do it right.
I say live with it as long as you can while you save up to do it right.

 

[Fixnfly]

I found some pics before the pour.




That's the building inspector in the background





The pics are not in order, the drain did eventually extend out from the slab. I remember the contractor bitching cause he underestimated the amount of gravel needed and I think he wanted me to make up the difference. Not my problem. The outer edges of the slab are very thick, I guessing over 14". I had to drill and break loose a chunk so the underground electric conduit was flush up against the wall for code.

 

[volleyball]

It does look like undisturbed soil so that looks ok. Definitely not enough stone, especially with the raised soil around the garage. Where does your drain go to? A lot of place do not allow them.
I got to thinking and I am now guessing you had a too wet mix. Easier for a hack to lay and last awhile until the warranty expires. The broom finish leads me to that also.

 

[Fixnfly]

It does look like undisturbed soil so that looks ok. Definitely not enough stone, especially with the raised soil around the garage. Where does your drain go to? A lot of place do not allow them.
I got to thinking and I am now guessing you had a too wet mix. Easier for a hack to lay and last awhile until the warranty expires. The broom finish leads me to that also.

The drain goes to nowhere. About 4' in front of the garage under the ground, I never use it and probably will end up filling it full of concrete, The floor is so uneven that any water flows to the back corners of the garage, completely useless. It's more of a workshop than a daily parking garage so it don't really matter. The broom finish was not my idea and I was told it was to keep someone from slipping when wet

 

[Fixnfly]

Thanks to everyone who provided input on this

 

[radrush]

The broom finish was not my idea and I was told it was to keep someone from slipping when wet

The broom finish was no doubt to hide the fact that this guy couldn't finish a floor with a decent hard trowel finish. A light broom finish will hind a lot of imperfections.

WWF placed on the ground...errrr, useless.

no curing or improper curing = cracks

In the pic I see how high the grade is on the back side of the building. Is the grade now shaped properly so that water runs off around and away from the building? Do you have drain tile around the building? Is it clear?

Those cracks could probably be fixed with some low viscosity crack healer.

 

[Falcon67]

Nice looking building!

The good thing I see is a decent wide and deep footer - that should minimize a lot of the settling and movement. If they didn't pull that wire up during the pour, then it's not doing much (any) good.

My old shop was a 20x24 and it had a nice epoxy floor - with a really big crack that ran diagonal across the entire 24 length. I wasn't there to super the pour, and basically got a slock job. I worked in there for 13 years without problems.

The current 24x40 has about a 2" slope starting half way across one end and wasn't quite square. The slope is either from the forms taking a hit on the corner during the pour or settling in the soil. I'm used to it and it's still a great building. Hopefully yours will settle down and it'll be OK in the long run.

 

[mudfly]

Misery loves company
Here's my cracked concrete story. 20'x25 slab. Long story short...Walls and footer poured with concrete truck backing up my driveway to new shop located behind my house. I have no problems with that pour. A few days later the crew (same company, different crew) shows up to pour slab. I noticed a pump sitting in the street at the end of my driveway. I wasn't a "concrete expert" at the time, but knew that I would prefer not to have the concrete pumped. I talked to the head concrete guy, and he said that they did not normally back a concrete truck up an existing driveway. I explained that I would prefer the truck and that his company just a few day earlier backed a truck up the driveway. By this time the concrete truck showed up and I let him talk me into using the pump mix concrete. It did look too wet coming out of the hose to me, but he told me that extra mortar and aggregate was added to compensate...yea right. After about 1 year and 3 months, here is what I have:
I don't have a "big picture" view of the slab at the moment, but I have about 7 of these cracks that start at various points and meet up with each other.
I assume, from what I've researched on this site, that I have shrinkage cracks due to too wet a mix. Not sure they are critical at the moment, but will keep an eye on them....Under, of course, what I decide to hide them under (tiles..etc.)
I think I am finally at peace with my concrete.
Hope this moral support helps!

 

[volleyball]

I had mine pumped as it was large and down a hill. I decided to skip the control joints and the only crack is where the pour is split into two rooms with a 6' doorway. It goes across the doorway which got covered by a door. It was expected as all floors crack. And yours doesn't look bad IMO. If the base is good they won't expand. The OP has shifting already.

Falcon, you are wrong about a good footer. Good for your area but not with northern frost heaves. And I don't see any rebar. That thing is going to crack and separate.

 

[volleyball]

In the pic I see how high the grade is on the back side of the building. Is the grade now shaped properly so that water runs off around and away from the building? Do you have drain tile around the building? Is it clear?

Now that I see the finished picture, doing this is the best thing in the world to preserve it. gravel and 4" pipe on the two sides and back the open up down the hill. If you reduce the saturating and drying of the base, it will go a long way towards reducing any more movement. I live on a hill and have become a sort of expert on drainage.

 

[Fixnfly]

I sealed the back of the garage with drylock and roofing tar. That did not stop all the water coming in the back so I dug it all back out by hand and installed a french drain system and leveled it off to the edge of the slab. Gutters working well. So far so good.

Mudfly, I feel your pain. It's pretty damn disappointing when you pay a lot of money for something and have high expectations, and then the cracks start.
I'm not planning on staying here forever so someday it will be someone elses problem. Hopefully they won't care.

 

[Falcon67]

Falcon, you are wrong about a good footer. Good for your area but not with northern frost heaves. And I don't see any rebar. That thing is going to crack and separate.

I was afraid of that, but not sure. Yes - OK around here and actually more than many use. No frost line here with a rare exception of extended cold. Our minimum here is two 1/2" bars in the footer and 3/8 bar 18" on center all over.

 

[raddksn]

He said shrinkage ha ha!

 

[radrush]

Falcon, you are wrong about a good footer. Good for your area but not with northern frost heaves. And I don't see any rebar. That thing is going to crack and separate.

Look closely, there is one pic that shows a cut section of WWF in the bottom of that wide turn-down slab. I guess the contractor figured the WWF as a substitute for rebar. WWF dang near useless when placed on the ground and "hooked" during the concrete placement. You're better off using a fiber concrete mix than WWF.

 

[volleyball]

I saw the mesh, no rebar substitute. Plus you don't just lay some #4 in middle and call it done.

 

[saltfever]

I don’t see any joints. No matter where it or what it is, ALL concrete must have joints to prevent random cracking. I don’t care if it is a runway in Thailand, a freeway, a polished Bank floor, or a garage. If it is not a post-tension design, concrete should be jointed for every cubic yard or less. Yes, “cubic” is volume but a floor is square area. You must take your slab thickness into consideration (i.e., 4”, 6”, etc.) do the math then joint the equivalent square area. As stated by all above, concrete will crack. Joints focus the tensile stress (created by shrinkage during the cure) along the joint and the crack develops there. If you don’t like an ugly troweled-joint look, then saw cut.

 

[Fixnfly]

Well it's been about 16 months since the pour, so when do the cracks stop ?
Or don't they?

 

[volleyball]

The shrinkage should be done, but movement may continue forever. Every season the ground heaves and then when it settles. Does it get wet in the cracks in spring? I had that in my basement when I first moved in but with some proper drainage and regrading, it has not come back.

 

[Fixnfly]

No water problems now but I did a lot of work to get it that way. Floor is almost always dry.

 

[Fixnfly]

The shrinkage should be done, but movement may continue forever. Every season the ground heaves and then when it settles. Does it get wet in the cracks in spring? I had that in my basement when I first moved in but with some proper drainage and regrading, it has not come back.

My yard is really bumpy due to all the freeze/ thaw cycles. No wonder the garage floor is so boogered up.

 

[pattenp]

Was the gravel base plate compacted? From your pictures it doesn't appeared to be compacted because the wire mesh is already down and the gravel looks loose.

 

[zporta]

im kind of confused why they would do a monolithic pour and they lay block on top of it? Why not footings then block foundation and then a slab? Also those footings do not look deep enough, here in MD our frost depth is 32" and im sure PA should be deeper. No rebar in footings or slab. Were there even inspections?

Also i just noticed gravel in the footing? Should be virgin ground no loose material

 

[Ch3No2]

I have been pouring concrete for 30 years...placed and finished..doing a lot of 10,000 sq ft slabs that are soff cut next day...even 3k psi...bottom line, it will crack...just allow a place for it to hide as much as possible...my .02cents

 

[radrush]

I saw the mesh, no rebar substitute. Plus you don't just lay some #4 in middle and call it done.

Mesh is for fencing. WWF, welded wire fabric, is for concrete.
If you know the cross sectional area of the WWF you can calculate the rebar equivalent.

 

[volleyball]

Yeah I was in the Navy and still called it a boat.

 

[Tejaas]

I can imagine that's frustrating for you, but I always viewed this as largely depending on where you live/build in general.

My wife worked for the firm (as an administrative) that did the unbonded/bonded post-tension cable and pour work for the "new" Dallas cowboys stadium... that's about as professional a job that can be done and they had a very impressive portfolio of prior work... And they have this happen all the time. It comes with the ground type.

Your cracks are just the unfortunate part of aging a slab goes thru, some earlier than others.

When my parents had their massive ranchhouse built here in the Texas Hill Country, we left sprinklers on the slab running for days on end to combat the summer heat... No problems at all, and it's been almost 15 years.

The guy "next door" (6 miles away) poured his new house slab ($750,000 house) on the same type surface (limestone bedrock atop a 300' bluff) and didn't keep his slab damp while it cured... Within two years his foundation had a slight crack almost completely across the halfway point... Which equated to his cathedral ceilings separating almost 4 inches at the peak! House got scrapped quick!

When we poured our slab for our equipment shed (over good and soft black dirt, and significantly a thinner slab) we didn't run water on it due to being miles away from our nearest well... A few hairline cracks and now it's settled and no further drift has occurred.

What I've seen done that always worked...wait a few years to allow it to "run its course"... chances are it will be just fine and then get a coat or two of quality epoxy down.


"You Ain't Done Wild & Reckless, Till You've Done It In Texas!"

~Tejaas~

 

[98ramtough]

***** about your floor. I have seen worse, but looks like there is not enough compacted rock base below it, the mesh should be rebar in my opinion, and it needs to be on adobe or stones to lift it up out of the concrete. I hate when I see people go along and pull it up as they pour. Don't ever settle for that. Do it right and put them on chairs, stones, adobes or even rocks, but elevate the metal a couple inches. I'd just live with it and save up for another garage...

 

[bczygan]

I'm pretty much on my own, "warranty " was for one year and has expired.
I really don't want to deal with the contractor again. Everything with him was an argument and I think this time I might end up grabbing him by the neck.
The broom finish was not my idea.

Well, at least this is an object lesson for others.

The lesson is to research construction methods and alternatives extensively, with a focus on best practices for your area.

And finding a contractor is a whole nuther book.

Trades like this require a skilled crew. There is artistry involved.

And the contract is your only protection.

You can still grind the slab to get a smooth surface and put a finish on it.