Dirt Fill under slab (Mudjacking ?)


Old 07-13-08, 09:40 PM
Thread Starter
Join Date: Dec 2007
Posts: 7
Received 0 Votes on 0 Posts
Dirt Fill under slab (Mudjacking ?)

I live in New Orleans and I have a few houses that are concrete slab foundation. The soil here is very soft so pilings are driven in the soil usually about 60 feet or less until the piling hits its refusal point. Next the slab foundation is poured with the support walls being poured on top of the pilings as a chain wall in unison for strength. At times these pilings will settle causing the slab foundation to sink.

Luckily my slabs are all in good condition without any sinking. I do however have void spaces where the dirt has settled. In some spots this is 24" in settlement. This creates a 24" void under the house where there used to be dirt all the way up to the bottom of the slab. I have received a quote for 1 of my houses for over 5000 to have the dirt replaced. This is a 1000 sqft house to give you an idea.

Naturally I have looked at mud jacking equipment anfd have found some that is less then 2000 for the equipment and therefore makes it very attractive to possibly just purchase the machine and do it myself. It appears that most how to's I find are in reference to riaisng the foundation and using grout. I clearly have no need to raise the foundation and all the the places I own or in pilings so this would not even work. In summary I just need to be able to move sand under the house so that the wood piling are not exposed and do not rot. It would also be nice to stop having the sand on the outside perimeter of the house stop washing under the slab everytime it rains.

I have also thought about using a foam to fill in the void but have not found any way to do this yet and have no idea if it would be cost effective.

Has anyone ever dealt with this or have any suggestions?
Sponsored Links
Old 07-15-08, 02:59 PM
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,986
Received 0 Votes on 0 Posts
Basically, you need a horizontal bulkhead for lack of a better description. If you dug far enough away from the house where you could lay some pressure treated wood flat, then filled the hole with a mix of sand, motar and gravel, it may stop the erosion. Just try one to see if it helps.

Another thought is use sono tubes that are used for regular footings. I would put heavy plastic at the bottom of each.
Old 07-15-08, 03:12 PM
Join Date: Mar 2005
Location: USA
Posts: 6,130
Received 0 Votes on 0 Posts
Dirt Fill under slab (Mudjacking ?)

Mudjacking pumps are not made to pump sand fill horizontally. They usually pump smaller amounts of cementitious grout under pressure and against some resistance. It may work, but you will not know until you get into it with your equipment or can find a mudjacking contractor willing to take the time on an experiment.

Filling the void is only a temporary fix considering the soil, but it will keep out the big critters for a while. Everytime there is a high water level (not really flooding), the pumping out pulls soil sideways and lets the soil settle more.
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: