Best way to lift sinking concrete driveway

[bean29]

My driveway slab directly in front of the garage sunk. This piece is not as important to repair as the walk just before you step up onto the porch. That slab is sunk possibly 3 inches.

I was googling how to repair yesterday, and I see there are two methods to repair or "Mud Jack". The first is the older method of injecting slurry underneath the slab to raise it up, and the second is to inject a chemical polyurethane foam underneath the slab to raise it up.

I live in Wisconsin. DH was told not to put the driveway in before we went through a freeze/thaw cycle, but he put it in anyways - he did not want to track all the dirt inside over the winter.

We have been in the house 15 years. There is rebar in the driveway. DH was thinking about replacing the concrete walk, but I am thinking we should lift the driveway in all spots where it sunk. I am also concerned that he will not deal with it before winter and that section in front of the porch will be a problem with water pooling and freezing.

So, is the polyurethane foam an option, or should we avoid it?

[Deleted]

I had a bunch of mud jacking done last Summer.  It was quick and relatively inexpensive and the results look good.   They raised my entire slab all the way across where it met the garage (3 car garage width), and the sidewalk where it met the front steps.  The sidewalk had sunk a LOT and water was going down under the steps and against the basement wall in the basement.  He probably raised it 8 inches and used a ton of mud because it oozes into all the gaps and filled in under the steps as well.  The mud has a cement mixture in it so it hardens.

I paid about $1500 for that job.  They guarantee it so many years, but I can't remember offhand how many. 

They do have to drill holes in the cement and they fill them with a putty afterwards.  The putty does not really match the cement.  It doesn't bother me, but I'm not particularly picky with things like that. 

[sheilaincali]

In my professional opinion (I own a concrete road construction company) - I'd go with the mud jacking. BUT note that if there are significant problems with your base you may have other problems down the road. It's not a common service- there's only one guy in my entire area that does it. I think I paid around $300 to have my sidewalk mudjacked a few years ago.


Fix the driveway BEFORE you replace the walk- it's much easier to do the walk to match the driveway once the driveway is fixed. But yes- pooling water and it freezing will be a concern this winter.  

[bean29]

Aug 23, 2019 15:11:40 GMT -5 minnesotapaintlady said:

I had a bunch of mud jacking done last Summer.  It was quick and relatively inexpensive and the results look good.   They raised my entire slab all the way across where it met the garage (3 car garage width), and the sidewalk where it met the front steps.  The sidewalk had sunk a LOT and water was going down under the steps and against the basement wall in the basement.  He probably raised it 8 inches and used a ton of mud because it oozes into all the gaps and filled in under the steps as well.  The mud has a cement mixture in it so it hardens.

I paid about $1500 for that job.  They guarantee it so many years, but I can't remember offhand how many. 

They do have to drill holes in the cement and they fill them with a putty afterwards.  The putty does not really match the cement.  It doesn't bother me, but I'm not particularly picky with things like that. 

Yeah, It would not bother me a lot either. I want my front walk raised before winter. I plan to stay till the house is paid off - so 8-9 years. By then we probably will need to replace the concrete anyways.

It did not occur to me that water may be running against my foundation there.   I am especially worried that an elderly relative might fall when they are visiting us. 

Apparently the polyurethane foam is better at "compacting the soils" and the holes they drill in the driveway are smaller.  I just know that when I mentioned you can use it for post holes, they guys didn't seem to think it was the best product to use.

[tskeeter]

At least with the driveway slabs, you might consider just cutting off the garage end of the slabs and pouring a new end to the slabs.  Might be less expensive than mud jacking.

Regarding polyurethane foam vs. mud.  Foam, by definition, has gas bubbles in it.  I think those gas bubbles will leak over time and may allow the foam to compress and the slabs to sink again.  What is referred to as mud is really cement without any rock in it.  Cement doesn’t compress very well.

Concrete has structural rigidity, which will help it bridge any spot settling in the future.  Foam doesn’t have much for structural integrity.  I guess that’s why we don’t have polyurethane foam freeway overpasses.

[OldCoyote]

Sky hooks are the cheapest!.

They are located right next to the Spools of pipe thread!

[mroped]

Replace the pieces that sank. Change a bit the slopes if you have to in order to match grades and so on.
Replacing it would allow you to have a do over of the sub base which it sounds like will settle more if you don’t compact it properly.

[happyhoix]

Aug 23, 2019 15:52:01 GMT -5 sheilaincali said:

In my professional opinion (I own a concrete road construction company) - I'd go with the mud jacking. BUT note that if there are significant problems with your base you may have other problems down the road. It's not a common service- there's only one guy in my entire area that does it. I think I paid around $300 to have my sidewalk mudjacked a few years ago.


Fix the driveway BEFORE you replace the walk- it's much easier to do the walk to match the driveway once the driveway is fixed. But yes- pooling water and it freezing will be a concern this winter.  

Oh good, an expert I can ask!

The people who built our house did a somewhat crappy job on parts of it (we didn't notice when we bought it, found out issues afterwards).

One problem is the driveway, it started cracking right away, and now, at 20 plus years, has multiple cracks and the slabs are uneven. I think this is primarily because they dumped a bunch of dirt along one edge to make the driveway area large enough, but didn't compact the dirt down very well before they poured the concrete. Now the slope has settled making the slab slope and crack.

I don't think they used rebar. Before we sell the house, we need to fix it, it's an eyesore.

Is it possible to remove the broken parts and the sloping slabs and repour around the still fairly level/uncracked parts, or will we have to excavate and repour the whole thing? It seems wasteful to dig up and remove all of it, but I don't want a crappy patch on what started out as a crappy driveway.

[tskeeter]

Sept 1, 2019 16:02:54 GMT -5 happyhoix said:

Aug 23, 2019 15:52:01 GMT -5 sheilaincali said:

In my professional opinion (I own a concrete road construction company) - I'd go with the mud jacking. BUT note that if there are significant problems with your base you may have other problems down the road. It's not a common service- there's only one guy in my entire area that does it. I think I paid around $300 to have my sidewalk mudjacked a few years ago.


Fix the driveway BEFORE you replace the walk- it's much easier to do the walk to match the driveway once the driveway is fixed. But yes- pooling water and it freezing will be a concern this winter.  

Oh good, an expert I can ask!

The people who built our house did a somewhat crappy job on parts of it (we didn't notice when we bought it, found out issues afterwards).

One problem is the driveway, it started cracking right away, and now, at 20 plus years, has multiple cracks and the slabs are uneven. I think this is primarily because they dumped a bunch of dirt along one edge to make the driveway area large enough, but didn't compact the dirt down very well before they poured the concrete. Now the slope has settled making the slab slope and crack.

I don't think they used rebar. Before we sell the house, we need to fix it, it's an eyesore.

Is it possible to remove the broken parts and the sloping slabs and repour around the still fairly level/uncracked parts, or will we have to excavate and repour the whole thing? It seems wasteful to dig up and remove all of it, but I don't want a crappy patch on what started out as a crappy driveway.

If you’re going to have to take out half of the driveway, or more, just taking the whole driveway out may make more sense.

Any of the existing slabs you keep will not match the new work in finish or in color.  It will always be obvious what you did.  And when you go to sell the house, you’ll likely get questions about why you replaced some of the driveway.  And you’ll have to answer that you had a settling problem.  That’s a big red flag for many people.  If the driveway settled, is the foundation of the house really stable?  Or will I have problems if I buy this house?

Another consideration is that trying to save some slabs and not others will probably slow down the demolition work a lot.  Because equipment operators will have to be very careful not to chip or damage the slabs you want to save.  And heaven forbid that they drop part of a slab they are removing on one of the slabs you want to save and damage the save slab.  The save some slabs approach will be a little like trying to remove tape from a piece of paper.  You might get lucky.  But, it’s more likely that you’re going to ruin the paper. And spend a lot of time trying to save the paper.  But ultimately, fail to save the paper undamaged.

[sheilaincali]

What tskeeter wrote is accurate.  20 year old concrete next to brand new concrete will look like an obvious patch job.  Plus it sounds like (given the amount of cracks and unevenness) you probably have a problem with the base. They will replace the base on the pieces you replace but the ones you're living will continue to age and settle poorly.

Your best bet is to demo and replace the entire thing.  Where do you live? If it's in a cold/winter climate DO NOT let them replace your driveway between basically November and March. There is a reason that MNDOT kicks us off the roads in the winter. For one thing they will charge you a winter service charge and you'll have to pay for heated materials. But honestly- if you live in a cold climate and a contractor tries to convince you that it's "fine" to do a driveway in the winter run far away from them.

Around here just about any idiot can add "concrete" to their last name and call themselves a concrete contractor.  Call your local ready mix supplier to ask for recommendations if you don't already have a concrete contractor that you trust.

[bean29]

I think around here the date they can safely pour concrete up to is mid-October. I asked DH to see if the guys that laid our paver patio can come back and put the leftover pavers we have in as a walk. The driveway slab that is sunk is father back, and minor. I might call the mud jackers, I have not yet discussed with DH. The sidewalk is obviously cracked - the driveway slabs did not crack - so it would not raise questions. Idk. the sidewalk needs to be done.  I will have to decide by Friday or so.

Right now I am off to send in a request to get a replacement window for the other maintenance project I procrastinated acting on.  A broken window that is still under warranty.  Grr. I will be home on Friday, so see if I can make some calls on the driveway then. - well, I have to finish this later - they want a photo uploaded and I did not take a pic on my phone yet.

[countrygirl2]

The mud jacker sounds great, we have a rent house and the driveway is like that, we  had planned to do nothing.  Well not nothing, hubs is digging up one piece to run a pipe under for the sump in the basement and the gutters on the driveway side.  On the other we are just running black pipe buried to the alley for the gutters.  We just don't want to spend a ton on the drive this year, we have the garage roof to finish.  So likely just fix what we need to.  Hubs knows how, he was a highway superintendent for many years, will likely fix it when some money starts coming in and have someone do it in a year or two.

[jkapp]

I used poly foam on my driveway for a three inch dip in the driveway.  It is much more expensive than mud jacking but tends to stay better as well.  I also had several cracks and the driveway was very uneven throughout.  They had to drill about a hundred holes into the driveway to even it all out but it ended up looking great.  It has been three years now and still looks good.

They did tell me to change where one of my downspouts was discharging, though.  One downspout was sending water out near the side of the house next to the garage and right in front of the driveway.  They said to move it so that it discharges onto the driveway instead.  The water was sinking down into the ground and washing away the dirt underneath the driveway.