Concrete garage floor woes

[ColdBlackWind]

I will not get into the story around why I am trying to salvage a new concrete floor but let's just say I have taken a beating from the installer and after 3 years of seeking relief I am where I am.

I built my attached garage 3 years ago. The intended use was a normal parking area for the daily driver and a show area for my Dodge Pro Street. The floor to me is the center piece of a garage and mine turned out to be much less. I am now trying to decide whether to tear it all out or try and grind/ fill / coat what is there. The garage is 48' x 36' and is bigger than my house!! I have an understanding wife. Plus it is two stories and she will have an 18' x 48' bonus room upstairs.

If I go the salvage route here are my problems. The floor has numerous humps, valleys, bird baths and cracks. It has, for lack of a better word, a trough around the entire perimeter that is about 18" wide and runs to the walls where it was troweled down lower than the grade of the rest of the floor. There are cold joints where the high and low spots look like moguls from an MX track that are 3/4" from high to low. No expansion material was used around the cement block foundation, I have one block above grade where the studwalls sit. The concrete floor bonded to the blocks and and when it started shrinking during curing it cracked extensively across the entire floor. I have had all the heartburn I can stand over this and can't finish the rest of the garage until I correct it.

To salvage it I was thinking grind high spots and cracks, fill low spots. There is an inch of elevation difference from lowest low to high spots. Hopefully more filling than grinding. I can do a laser level map of the floor. Any help or suggestions on a large aggressive grinder, dust control and a material to fill low spots that can be painted would be greatly appreciated. One consideration is that I can do a new floor for about $5000 if I tear out the old (new) one. That also brings the risk of damage to peripheral walls and a cellar that I put under an attached section. Also the dust is an issue as I mentioned the bonus room above and the fact it is attached to my house.

Thanks in advance for any help.

 

[NitroSun]

Pics would help. If you have one block of height under the walls, can't you just pour 4" on top of what you have ?

 

[Garage Flooring]

I will not get into the story around why I am trying to salvage a new concrete floor but let's just say I have taken a beating from the installer and after 3 years of seeking relief I am where I am.

I built my attached garage 3 years ago. The intended use was a normal parking area for the daily driver and a show area for my Dodge Pro Street. The floor to me is the center piece of a garage and mine turned out to be much less. I am now trying to decide whether to tear it all out or try and grind/ fill / coat what is there. The garage is 48' x 36' and is bigger than my house!! I have an understanding wife. Plus it is two stories and she will have an 18' x 48' bonus room upstairs.

If I go the salvage route here are my problems. The floor has numerous humps, valleys, bird baths and cracks. It has, for lack of a better word, a trough around the entire perimeter that is about 18" wide and runs to the walls where it was troweled down lower than the grade of the rest of the floor. There are cold joints where the high and low spots look like moguls from an MX track that are 3/4" from high to low. No expansion material was used around the cement block foundation, I have one block above grade where the studwalls sit. The concrete floor bonded to the blocks and and when it started shrinking during curing it cracked extensively across the entire floor. I have had all the heartburn I can stand over this and can't finish the rest of the garage until I correct it.

To salvage it I was thinking grind high spots and cracks, fill low spots. There is an inch of elevation difference from lowest low to high spots. Hopefully more filling than grinding. I can do a laser level map of the floor. Any help or suggestions on a large aggressive grinder, dust control and a material to fill low spots that can be painted would be greatly appreciated. One consideration is that I can do a new floor for about $5000 if I tear out the old (new) one. That also brings the risk of damage to peripheral walls and a cellar that I put under an attached section. Also the dust is an issue as I mentioned the bonus room above and the fact it is attached to my house.

Thanks in advance for any help.

Pics would help. If you have one block of height under the walls, can't you just pour 4" on top of what you have ?

Some pictures with a level or large straight edge and something for a relative measurement.

 

[rancherbill]

I have two thoughts.

It's not over yet. There seems to have been a compaction problem and they can go on for a while until 100% compaction occurs.

Secondly, mud jacking will get the floor into usable condition and if there is subsequent problems it will allow you a full range of strategies. Grinding an unstable floor will just make it more prone to cracking as the subsequent settling occurs.

Where are you located? Put it in your profile.

 

[ColdBlackWind]

Pics would help. If you have one block of height under the walls, can't you just pour 4" on top of what you have ?

My man doors are at grade and I would need to reframe and tear out stone on the outside to raise them up. That is an option!! Wonder if two inches would be enough.

 

[ColdBlackWind]

Some pictures with a level or large straight edge and something for a relative measurement.

I have trouble with pics but will try. Hard to get anything that shows lowest low to high spots as they are from center of building to corners. Will try.

 

[ColdBlackWind]

I have two thoughts.

It's not over yet. There seems to have been a compaction problem and they can go on for a while until 100% compaction occurs.

Secondly, mud jacking will get the floor into usable condition and if there is subsequent problems it will allow you a full range of strategies. Grinding an unstable floor will just make it more prone to cracking as the subsequent settling occurs.

Where are you located? Put it in your profile.

The floor was this way from day one except the cracks. They showed up Day three. I like the idea of a poured floor on top of tis one if a product is available that would bind to the scarified concrete and have enough tensile strength to hold up. I only have about 2 " to work with which would be 1" over the high spot. Grinding the high spot is an option. All the doors will have to be raised also which means exterior finish work issues.

 

[mrpizza]

I would have hired a lawyer and gone after that POS. There is a big difference between acceptable minor imperfections and what you describe.

 

[ColdBlackWind]

I would have hired a lawyer and gone after that POS. There is a big difference between acceptable minor imperfections and what you describe.

I did. The cost of recovery, if any, far outweighed the cost of the floor. I amnot exagerating the problems. I can roll across it on my shop stool and its like riding a roller coaster. When I push my boat in by hand I have to hold onto it once it gets to the center of the garage because it takes off to the back on its own. The guy was a good framer but got in over his head when he tried to do the floor with one other helper. Just a cluster. Hard lesson learned as it has bummed me out for 3 years. The garage was my dream place to finally get all my racing memorabilia and car into one place.

 

[joes169]

As a concrete contractor, I'm sorry to hear of your issues, it looks bad for all of us that actually stand behind our work, & I generally don't like to hear that someone was taken to the cleaners.

That said, if you are sure you can get a tear-out and replacement for around $5000.00, I'd likely go that route. Grinding anything more than the paste off of the top of a concrete floor is extremely slow. Scarifying is faster, but it still leaves you with a mess that requires days of grinding. When it's all said and done, you're still going to have to spend a wad of cash & labor on a coating over a less than stellar floor. I would cut your losses now, as the best way to a flat floor is to get a crew to pour a floor flat from the beginning.........

 

[NitroSun]

My man doors are at grade and I would need to reframe and tear out stone on the outside to raise them up. That is an option!! Wonder if two inches would be enough.

I don't know. If you can tear it all out and start over for 5k, might be the way to go.

Good luck

 

[gregtwojeeps]

Putting a two inch concrete pour on top is too thin and will just end up being another two inch cracked mess and any "coatings" will fail eventually and just transcribe the failed pour below it. Joe nailed it above for the right cure. $5k is a lot of money, so a person needs to decide whether they can live with a shop floor like this or not. JMO

 

[99PanozAIV]

I have two thoughts.

It's not over yet. There seems to have been a compaction problem and they can go on for a while until 100% compaction occurs.

Secondly, mud jacking will get the floor into usable condition and if there is subsequent problems it will allow you a full range of strategies. Grinding an unstable floor will just make it more prone to cracking as the subsequent settling occurs.

Where are you located? Put it in your profile.

My garage floor developed a few cracks and a "hollow" sound in one location. There is a local guy here who has a "slab-jacking" business which injects concrete under high pressure into the sub floor space. Mine took about 3 cubic yards in a regular two car garage. The only sign it's been done are small holes about every square yard. If the surface of your floor is uneven because of defective surface prep, this obviously won't help. If it's due to the slab cracking and settling unevenly, this will do the trick. He said he can fill, level or lift sections or an entire floor, depending on what's needed. I'm in Maryland BTW.

FWIW, this guy said it's unfortunately very common for earth compaction and settling to occur under concrete slabs; you'd think by now people would know how to do it right. He has a business fixing just these problems so I'm sure he's speaking truth.

 

[ColdBlackWind]

In my mind I had came to the tear out and replace point but my heart said if I could make lemonade out of lemons I might be able to get a ground and coated floor that would be really nice if all the filling, grinding, coating came out nice. Lots of work and lots of mess. My only issue with tear out is what the slab will do where it was poured against the block. I can't afford to have the block damaged and sawing creates such a mess..... I also hate the sawed expansion joints. Are keyways a decent option or is it better to caulk the sawed joints? What is a reasonable degree of levelness to ask for on a slab that is 44' x 36'?

 

[kd3pc]

In my mind I had came to the tear out and replace point but my heart said if I could make lemonade out of lemons I might be able to get a ground and coated floor that would be really nice if all the filling, grinding, coating came out nice. Lots of work and lots of mess. My only issue with tear out is what the slab will do where it was poured against the block. I can't afford to have the block damaged and sawing creates such a mess..... I also hate the sawed expansion joints. Are keyways a decent option or is it better to caulk the sawed joints? What is a reasonable degree of levelness to ask for on a slab that is 44' x 36'?

should be less than 1/2" across the lengths, if you asked for level. Level means flat, there are no degrees of levelness, it is either level or it isn't.

Tear out and replaced by a qualified concrete team.

best of luck