# How to Fix a Sinking Foundation: Underpinning > The ugly truth is that in a world full of expansive soil, fill soil , and gravity foundations sink. Schedule a free evaluation with Dalinghaus. _Brian Dalinghaus · 2021-09-01_ --- The ugly truth is that in a world full of **_expansive soil_**, **_fill soil_** **_,_** and **_gravity_** foundations sink. In the foundation repair business, we refer to this sinking as **_foundation settlement_**. _**[[sign:foundation-repair/sinking-foundation|Foundation settlement is always]] due to incompetent, non load-bearing soil.**_ This forces the home to either **_sink_** or **_swim_**. When the house sinks, this causes undue pressure and stress on your home's foundation, resulting in a myriad of [**_signs and symptoms_**](/foundation-repair/problem-signs/drywall-cracks/). All we ask in return is your email. Sounds like a good trade to me. [Schedule a free evaluation](/contact-us/) A sinking foundation is a problem for a variety of reasons, but the biggest issue is it hits you where you hurt most: **_your pocketbook_**. Nothing quite sinks your **_home equity_** like a fouled-up foundation. This is such a major issue we have two whole articles dedicated to it: - [**_5 Reasons to Fix Your Foundation Now_**](/foundation-repair/) - **_[[service:foundation-repair/real-estate-inspection|Sell Your Home with Foundation Issues]]_** So, the question remains, how do you throw a lifejacket on your home's sinking foundation? The answer: **_underpinning_**. Read more: **Is my foundation sinking?** ## What Is Underpinning? Underpinning is the **_strengthening_** and **_reinforcing_** of an existing foundation, typically by extending the **_depth_** and **_breadth_** of the foundation. Questions we've received on the topic of underpinning include: - What exactly is underpinning? - What is underpinning a house foundation? - Is underpinning beneficial? - When should you think about underpinning services? Well, since you asked, we've answered. In this article, we are going to cover 5 main types of underpinning: - _**Mudjacking/Slabjacking**_ - _**Caisson and Girder Beam**_ - _**Push Pier Systems**_ - _**Helical Pier Systems**_ - _**Polyurethane Foam**_ So, let's pin the tail on this donkey. Read more: **[[solution:foundation-repair/foundation-underpinning|Underpinning VS Foundation Repair]]** ## Mudjacking and Slabjacking Underpinning Mudjacking is a form of underpinning that has been around since the 1950s and is now considered by many foundation repair professionals an **_antiquated_** form of foundation repair. Mudjacking is the **_lifting_** or **_leveling_** of a foundation, driveway, or slab by pumping a mixture of slurry ( **_cement, sand, and soil_**) into application holes, the incredibly high delivery pressure raising the sunken slab. Mudjacking follows the **_drill, pump, patch_** application model. It is referred to as mudjacking because mud is a synonym for cement, which is funny because if we trace **_mudjacking_** back to its Greek roots, it's a synonym for " **_bad idea_**." The problems with this form of underpinning are endless - The application is messy and invasive, with application holes being **_2-3 inches_** in diameter. These holes do not add any aesthetic value to your slab and can compromise its structural integrity. - You're **_adding weight_** to a sinking ship. Adding more weight to an already sinking foundation proves ultimately unhelpful, what we call in the business, counterproductive. While mudjacking can fix your sinking foundation, it's not the best option. On the official **_Dalinghaus Underpinning Effectivity Scale_**, we give mudjacking a **_2 out of 10_**. It's messy. It's often a temporary fix. It's old-school. We've evolved, we no longer need to play in the mud. ## Caisson and Girder Beam Underpinning Caisson and Girder Beam underpinning is like a blunt force trauma instrument. There's no sophistication. We've all seen caissons, huge concrete pillars that hold up **_bridges_** and **_freeways_**. Now, imagine burying **_2 or 3_** caissons underneath your current home's foundation. Yes, it's as **_chaotic_** and **_cumbersome_** as you envision. The home becomes a construction zone. We're talking **_orange cones_**, **_a crane_**, **_massive holes_** ripped through your foundation, and a **_dug-up_** home looking like WWI trenches. The home is dug up for the grade beam application. A grade beam is an addition to a building's foundation that is a **_reinforced concrete beam_** that redirects the load from a bearing wall, dispersing the load between caissons. **_This project can take anywhere from 1-5 months._** That's a _helluva_ of a long time to spend with your in-laws or holed up in some cheap motel. This problems with this form of underpinning are: - Caissons simply **_add more weight_** unless they reach bedrock. To learn more about caisson and girder beam repair, check out our article **_:_** [**_Why Grade Beams & Caissons Don't Work Well for Foundation Repair._**](/framing-repair/) While caisson and girder beam underpinning could potentially fix your sinking foundation (if it hit bedrock) it is far from the optimal solution. On the official **_Dalinghaus Underpinning Effectivity Scale_**, we give Caisson and Girder Beam underpinning a **_3 out of 10_**. It turns your home into a construction zone. It only works if bedrock is accessible. It's so damn expensive, you might as well get a Fine Arts Degree. ## Push Pier Underpinning Push Pier underpinning is a relatively new technology that utilizes **_steel interlocking pipes_** that are hydraulically driven into competent, load-bearing soil and anchored to a home's foundation via a remedial bracket. They act as **_underground stilts_**, keeping your home steady. Push Piers prove a viable, practical, affordable option to securing your sinking foundation. Push piers **_secure_**, **_stabilize_**, and/or assist in **_lifting_** the home back to [**_maximum practical recovery_**](/foundation-repair/). Push piers have a relatively simple **_application process_**. - Comprised of galvanized steel to **impede rust/oxidization** - Driven until the hydraulic gauge proves the pier can carry its share of the load, rather than to a published capacity figure - In sizes ranging from **2-7/8"**, **3.5"** and **4.5"** (and are measured by the diameter of the pipe) - Generally pushed down to a depth of **25** to **30** feet - Comprised of three main components: **Remedial Bracket**, **Starter**, & **Extensions**. Push piers steel systems are **_far less invasive_** than mudjacking and caisson & girder beam underpinning. The entire project usually only takes a week, 2 at most. The one downside to push piers is that because push pier installation relies on the **_weight of your house for installation_**, it is not always conducive to single-story homes. On the official **_Dalinghaus Underpinning Effectivity Scale_**, we give push pier underpinning a **_9 out of 10_**. ## Helical Pier Underpinning Helical pier underpinning is also a newer, more streamlined form of underpinning. They are definitely a Grade-A option in securing your sinking foundation. Helical pier underpinning utilizes steel **_circular_** or **_square_** pipes that are **_hydraulicly screwed down_** to competent, load-bearing soil. They are attached to the foundation via a remedial bracket and help **_secure_**, **_stabilize_**, and/or **_lift_** a structure. Helical piers also act as **_underground stilts_**, **_anchoring_** your home into competent, loadbearing soil. **_The entire project only takes 1 to 2 weeks_**. - Comprised of galvanized steel to impede **rust** or **oxidization** - Come in sizes ranging from **3′**, **5′**, **7**', **10′** or **20′** - Comprised of a **lead**, **extensions**, & **remedial bracket** - Generally pushed down to depths of **25 to 30** feet On the official **_Dalinghaus Underpinning Effectivity Scale_**, we rate helical pier underpinning a **_9.5 out of 10_**. ## Polyurethane Underpinning Polyurethane underpinning is similar to mudjacking in the **_drill_**, **_pump_**, **_patch_** application model, but proves far less invasive. The application site is only **_5/8ths_** inch. Here at Dalinghaus, we often use polyurethane in conjunction with push pier and helical pier systems to **_void fill after a lift_**. However, in some instances, polyurethane foam can underpin solo. Polyurethane foam is an injectable polyol and isocyanate resin sealant, insulation, grout which expands upon application providing **_void fill_**, **_structural support_**, and **_re-leveling properties_**. Polyurethane is, in short, a gift from heaven and sure to address your sinking house. We love polyurethane so much; we have 3 whole articles about it - [**_5 Steps to Polyurethane Foam Injection (From Drill Holes to Cure)_**](/foundation-repair/solutions/polyurethane-foam-injection/) - [**_Polyurethane Injection VS Mudjacking (weight, application, and cure time)_**](/foundation-repair/solutions/polyurethane-foam-injection/) - [**_How Much Does Polyurethane Cost (From Void Fill to Deep Injection)_**](/foundation-repair/solutions/polyurethane-foam-injection/) On the official **_Dalinghaus Underpinning Effectivity Scale_**, we rate polyurethane underpinning a **_10 out of 10_**. It can reach every nook and cranny. It's typically a one-day operation. ## Choose Dalinghaus to Underpin Your Foundation Dalinghaus Foundation Repair can help you address a sinking foundation with helical pier, push pier, and polyurethane underpinning. We do foundation underpinning the right way. ## Schedule a Free Evaluation Foundation movement is easier to judge in person than from a photo. [Schedule a free evaluation](/contact-us/) and a Dalinghaus specialist will walk the property with you and explain what the evidence shows.