Leveling a Garage Floor...?

[Model A Fan]

I have a garage floor that is not level (concrete settled years ago and has a noticeable angle at the back 1/3 of the floor. It is a standard depth garage...meaning it is a little over one car length in depth. It is about a 2.5 car garage, so the piece of cement is sizable. My question is, is it possible to "jack up" the concrete similar to what you can do for concrete pad leveling, using the expanding foam, if the concrete piece I'm needing to level is several feet thick and about 20something feet long? Its a lot of concrete.

 

[rpcraft]

Floor leveling systems will often use a pier and beam but now days some will use a pumpjack method using mud or self expanding foam. I'm sure there are other ways I am not familiar with as well.

 

[ConCretin]

My question is, is it possible to "jack up" the concrete similar to what you can do for concrete pad leveling, using the expanding foam, if the concrete piece I'm needing to level is several feet thick and about 20something feet long? Its a lot of concrete.

I'm curious about a couple things; Why do you think the area to be leveled is several feet thick?? Are you sure the floor wasn't placed with a slope? Is the existing floor cracked?

 

[Model A Fan]

I'm curious about a couple things; Why do you think the area to be leveled is several feet thick?? Are you sure the floor wasn't placed with a slope? Is the existing floor cracked?

The floor is cracked lengthwise of the garage and the backside of the garage is not on the same level as the front side. It is approximately 2' from ground on the backside to floor level, so I'm sure it extends deeper into the soil.

 

[Armorpoxy]

We have posted a number of times about how to level floors with cementious type floor levelers.

 

[Model A Fan]

Any other ideas?

 

[signcrafter]

The floor is cracked lengthwise of the garage and the backside of the garage is not on the same level as the front side. It is approximately 2' from ground on the backside to floor level, so I'm sure it extends deeper into the soil.

We have posted a number of times about how to level floors with cementious type floor levelers.

If I'm understanding him correctly the floor is sunk 2' in one side. I don't think there is a cementious floor leveler out there that will cover that thick and if there is then you will need several cement trucks full of it.

If your floor is really sunk 2' down then your best option(only option in my opinion) is to rip it out and pour a new floor. Probably be cheaper then any leveling that might be done to fix that big of a difference.

 

[JR 42]

I read it as the slab being 2' above grade at the back, making him think the slab is 2' thick, and that the the back part isn't in the same plane as the front. I don't see where he said how far out of flat it is...

 

[signcrafter]

I read it as the slab being 2' above grade at the back, making him think the slab is 2' thick, and that the the back part isn't in the same plane as the front. I don't see where he said how far out of flat it is...

"if the concrete piece I'm needing to level is several feet thick and about 20something feet long? Its a lot of concrete."

Ok, so no matter how you read it the slab is way out of whack and based on the lack of description by the OP I'll still stick with best to rip out and start fresh. No clue what he means but when you are talking about 2' thick it's not a good situation.

 

[inphx]

Perhaps he is seeing the stem wall on the back end?

 

[ConCretin]

Any other ideas?

I think we are all having trouble picturing what your slab conditions are. Maybe some pics would help.

 

[Model A Fan]

OK, I'll have to grab photos tonight.

The floor in the garage has a long crack running lengthwise in the garage. The degree of angle on the floor is slight, but you can notice it when you're standing on the area that has cracked and is "sinking".

The garage sits on a slope, so it is level with my driveway in the front of the garage, but the slope is such an angle that the garage pad is 2' from ground level in the back.

 

[BillK]

The cement is not going to be 2ft thick. It will be sitting on fill material. Include some pictures from the outside.

 

[derek_m]

You have fill underneath the slab. What likely happened is the fill compacted and settled, allowing the slab to sink and finally crack when it couldn't flex anymore.

If the slab is in fairly good shape, mud jacking should be able to take care of it. I just had mine done, raised sections of the slab almost 3" to get the joints to line back up and "level" out. Note when you do this some cracks may open up. They drill 1" holes to pump the concrete in, patch with backer rod grout and some kind of sealer. My garage is 900sqft and it cost $1800 with a 3 year warranty.

 

[i4ni]

Time to get your hands dirty. If it were mine I'd dig down in the back to see if it sets on a footer and a wall or if it's just a thickened edge that was poured with the floor. You haven't said either way so realistically we can't help until we know if it's framed on a perimeter wall or if it's framed on the floor. Next thing I'd do is drill the floor in several places and then near the crack to determine how thick the concrete actually is. If the whole back edge has sunk the building is going to be out of whack but you haven't clarified if that is the case or not.So i'll reserve any advice until we know more.

 

[The Cobbler]

you probably have a monolithic pad . there is a perimeter of concrete "footings" that slope up to a pad that is 5 or 6" thick .
my garage pad is monolithic, due to slope in the yard the perimeter of the pad is 2' thick or deep . the bottom of the perimeter is 8" wide, and then 45° to the bottom of the base , the pad is about 6" thick. if you looked at it with the rear door opened, you could think the concrete pour was really thick.
even if someone worked at a concrete place, I don't think they would do a 24" pour.

 

[ConCretin]

I agree with those that think it's unlikely you have 2' of slab concrete. It is more likely there are frost walls around the perimeter and the slab was placed on backfill within or it's possible you have a monolithic slab with thickened edges although 2-3 foot deep haunches would be a little unusual.

I'm not an expert in slab jacking but if you do have a monolithic slab, i would think it unlikely they could move such a large mass of concrete. If it's a slab within frost walls, it should be doable.

 

[Model A Fan]

Hopefully what you guys are saying is correct...a shell on top of fill.

Here are some pics I took tonight. Monolithic...that would be a lot of weight for sure. Judging by how some of the work was done though...I wouldn't put it past the rocket surgeons who did some DIY on my house to do something dumb like that though.

 

[Model A Fan]

Any thoughts on what "lies beneath"?

 

[Model A Fan]

Any thoughts on what "lies beneath"?

Pictures have been added!

 

[ConCretin]

It appears to me that you have frost walls with a slab poured over them. There is a construction joint clearly visible. It appears the the slab is thicker in some areas but I suspect it's just poor formwork.

It's impossible to tell how thick the slab actually is but since it's bonded to foundation walls and has the structure built upon it, jacking would be tricky.

Jacking may level the floor but you'll still have the cracks. An overlay would level and the floor and provide a new surface. You'd need the existing floor to be stable and take steps to control cracking in the new concrete but it might be an option depending on your goals and budget.