What is Mud Pumping?

What is Mud-Pumping? Fill Voids Under Your Slab with Foundation Repair

You’re researching foundation repair options and have come across the term “mud-pumping” and you want to know what it means. Or maybe you are thinking about when a foundation is lifted, what happens with the space underneath your home? There’s a void there now and does it get filled in or what?

Mud-pumping is a finishing step of foundation repair, but not every foundation repair contractor adds this final step. It’s not automatically done so you might be wondering why some companies would use this technique or what its advantages and disadvantages are.

Anchor Foundation Repair

At Anchor Foundation Repair, we have been repairing foundations since 1985 and began adding mud-pumping to all slab-on-grade foundation repairs in 1998. We decided to take every reasonable step to provide the most security and stability in foundation repairs to Brazos Valley homeowners and bought our first hydraulic mud pump at that time.

We know mud-pumping has great value and importance in a foundation repair project, it’s a standard part of our slab foundation repairs. But we can tell you about it in an objective way so that you can decide if it’s as important to you as it is to us. 

We know that not everyone is trying to meet the same goals in selecting a foundation repair method or provider. We just want to give you all the information and options so that you can choose what works best for you and your home.

Why is Mud-Pumping Used in Foundation Repair?

In a nutshell, foundation settlement coupled with foundation repair creates voids. Here’s why: a home with a slab foundation is built on the ground. Homes are heavy. Over time, the weight of the home will compress and compact the soil below it. 

This initial compression causes the home to sink into the ground a bit. This is called settlement, and it’s not a bad thing unless it causes foundation problems for your home.

Settlement can also occur because of the expansive clay soil we have in this area. Expansive clay expands when wet and contracts when dry. The drier the soil gets, the more it can contract, also causing a home to sink. It might not all sink evenly. This is how slab foundations can crack and possibly need repair.

During the repair process, the home is raised back up to its original elevation. So imagine that the home is lifted, but since the soil was compacted below it, now there is space between the ground and the bottom of the slab. This is also called a “void” which is a fancy word for empty space. I mean, technically there’s air in the space so it’s not totally empty but . . . 

Now, you could just scream into the void underneath your home. But more productively, you can consider filling it with mud-pumping material so that there is not a bunch of empty space between the bottom of your home and the earth. Mud-pumping helps lessen the opportunity for more foundation settlement or problems to arise.

Is Mud-Pumping Necessary in Every Foundation Repair Project?

Mud-pumping is not typically needed for pier and beam foundations, but for slab-on-grade foundation repair, it is an option. While mud-pumping is not *required* in foundation repair, it has many benefits for the homeowner. 

So no, mud-pumping is not necessary to complete a foundation repair project, and many foundation repair companies don’t do it. Even though foundation repair contractors often skip this final step, you may want to seriously consider it. All the “whys” are in the next section.

Pros of Mud-Pumping with Foundation Repair

Nature doesn’t like empty things, nature wants to fill them up. This is that “nature abhors a vacuum” thing. If the void under your home doesn’t get filled with mud-pumping material. It will very likely get filled with something else, like:

pros of mud-pumping for foundation repair
  • Water and/or moisture
  • Erosional and unstable dirt
  • Your slab again
  • Critters

PRO #1: So one of the pros of filling voids with mud-pumping is that it takes up that empty space and prevents those areas from getting filled with something less desirable. The slurry material flows and fills every little space, permeating even the smallest pockets of air. But there are a couple more compelling reasons for you too . . .

PRO #2: Empty space creates weaker points and added stress to the foundation where it is not directly supported. Mud-pumping provides extra stability and holding power to your foundation without empty spaces under it. Having something solid underneath your whole slab is more supportive than drilled piers or pressed piles alone.

PRO #3: Mud-pumping the voids under your foundation also minimizes the risk of further movement and settling. When things are all snug and surrounded by other material, it’s less likely for them to wiggle and move around. It’s kinda like tucking your kid in at night. You burrito that little one in good with the hopes that they will stop moving and fall asleep, right?

Side Effect Bonus PRO #4: The step before mud-pumping is testing your under-slab plumbing to make sure there are no leaks. If leaks are found, they need to be fixed first. So if mud-pumping is used on your foundation repair, you will have the added comfort of knowing that there are no leaks or that they have been repaired. This is another way to make sure that further problems don’t come up later for your foundation or underneath it.

BCS Foundation Repair

Cons to Mud-Pumping During Your Foundation Repair

Foundation Repair Solutions for the Brazos Valley

Like anything else, there are a few cons to mud-pumping as part of your foundation repair. Even though we are a fan of mud-pumping, it does have some risks and downsides that we want you to be aware of.

CON #1: Mud-pumping costs more. This is an additional step that takes added time and more materials, SO there will be extra cost to you. Mud-pumping adds between $2,000 and $4,000 to the price of your average-sized foundation repair.

CON #2 (minor): There is a small risk of over-pumping the mud and adding too much material under the home. This can cause a hump in your floor. But with an experienced team working on your foundation repair project, this has a low chance of happening. Just want you to know this is a potential problem that could happen with an inexperienced or less careful contractor.

CON #3: Just like that kid that you tucked into bed with a burrito blanket, there’s no guarantee that no more movement will take place. Mud-pumping is a safeguard, an insurance policy, a risk minimizer, but it’s not an absolute settlement solution with no potential for failure.

Like many forms of insurance or safeguards, you don’t really know if you’re going to need it or not. You might only know the value of mud-pumping afterward in hindsight since we can’t predict what will happen later with your home.

How and When is Mud-Pumping Done in Foundation Repair?

Mud-pumping for foundation repair

As mentioned, mud-pumping is a final step in a foundation repair project, but it has a few steps of its own to complete the process. Here’s a breakdown of how it works:

  1. Raise the foundation and secure it in place with shims
  2. Test under-slab plumbing lines to make sure there are no leaks
  3. Set up temporary pipes to pump the mud under the slab in the lifted area
  4. Mix slurry and pour into mud-pumping machine
  5. Pump slurry into foundation repair holes until tight, remove pipes and clean up

The mud-pumping process takes about half a day or small projects and several delays for larger jobs at the end of a foundation repair project. So it doesn’t add a lot of time to the job but it can add some peace of mind.

Decide if Mud-Pumping is Important for Your Foundation Repair

What’s the worst-case scenario if you don’t do mud-pumping? Well, you could spend thousands of dollars on a foundation repair only to have it settle all over again due to missing that final step and leaving voids under your foundation. 

Bryan College Station Foundation Repair

On the flip side, your home can still settle no matter what you do (or it might not, there’s no way to know for sure) but the risk is minimized as much as humanly possible if you add mud-pumping to the repair. This seems like a tricky decision, so let’s try and make it a little easier with some “if-then” statements.

  • If you love your home and plan to be in it for the long haul and want the very best, get the mud-pumping.
  • If you want to do everything possible to avoid more foundation repair in the future, mud-pumping is for you.
  • If you are trying to save money on your foundation repair, then mud-pumping might not be the right choice for you.
  • If you are selling your home and won’t be living in it any longer, then you’re not worried about the longevity of the repair and could skip the mud-pumping.

Anchor Uses Mud-Pumping in Slab-on-Grade Foundation Repair

Anchor Foundation Repair Lifetime Warranty

Here’s one more “if-then” statement for you: if you want to use Anchor Foundation Repair for your slab-on-grade foundation repair project, then mud-pumping is part of the deal. We don’t leave repair projects without the last step because we also have a lifetime warranty and service agreement

We can’t offer that warranty without safeguarding our repairs and minimizing re-settling risks as much as possible.

At Anchor Foundation Repair, we have seen firsthand the consequences of not filling voids after repairs in our 35 years in business. We have inspected and repaired dozens of homes that had previous foundation repairs (by other companies) without mud-pumping. We have felt the hollow-sounding floors and seen homeowners having to go through the repair process again to get it right the second time.

To get it right the first time, Anchor employs more than one “risk-minimizing” tactic to provide the longest-lasting foundation repair possible. Check out our article highlighting 4 service features that set us apart from other foundation repair contractors.