What Are the Disadvantages of Underpinning?

The disadvantages of concrete underpinning are that it is costly, can be obstructive, can be intrusive, and can take a long time to complete.

Concrete underpinning has been a highly effective construction practice for over a century. But there are some disadvantages to using this method that homeowners should be aware of when searching for underpinning contractors in Adelaide.

In this article, we’ll run through some of the advantages and disadvantages of concrete underpinning and explore the alternatives. 

5 Main Disadvantages of Concrete Underpinning

The 5 main disadvantages of concrete underpinning are:

  1. It can be expensive
  2. Depending on the location, underpinning can be obstructive
  3. It can be intrusive to underpin internal walls
  4. Bad access is very challenging
  5. The underpinning process can take up to 3 weeks

5 Main Advantages of Traditional Underpinning

The 5 main advantages of underpinning are:

  • Concrete underpinning has been around for over a century. This method of foundation repairs is a tried-and-true method for repairing and strengthening foundations.
  • Traditional underpinning requires engineering expertise. As traditional underpinning needs an engineer to design the plans, you know you’re in safe hands.
  • Underpinning rarely fails. When using a licensed contractor, engineered underpinning usually leads to excellent results. 
  • In case of issues, the underpinning contractor can come back and make the necessary adjustments. With other methods like resin injection, this cannot be done. 
  • Underpinning is highly effective. There aren’t many scenarios where underpinning doesn’t work.

What is Resin Injection?

Resin Injection is a technique used to stabilise structures and pavements that have undergone displacement caused by differential settlement. Homeowners prefer this approach because it does not involve excavation or the installation of supplementary structural components like underpins.

However, engineers have debated its efficacy, with much controversy surrounding it. Although it has demonstrated its effectiveness in reducing liquefaction beneath buildings caused by earthquakes, its long-term efficiency and success for shallow-founded residential houses experiencing differential settlement on reactive soils remain uncertain.

Is Resin Injection As Good As Underpinning?

No, resin injection isn’t as good as underpinning. It cannot be engineered, and if it fails, it cannot be reversed.

We don’t recommend using a method where you can’t estimate the cost, can not rectify any mistake, or can damage the surroundings permanently.

Can Underpinning Fail?

Yes, underpinning can fail for the following reasons:

  • The underpinning was not engineered
  • The method of underpinning is not appropriate for the soil conditions
  • The foundation is not adequately prepared before underpinning
  • The load on the underpinned foundation is too much

All these reasons can lead to failure of underpinning. That’s why working with a qualified contractor with experience in underpinning is very important. Want to know how long does it take to underpin a house? Have a read of this article. 

Underpinning is a process of stabilising and restoring the foundation of a house. Having your home checked for any signs of foundation failure is important, as failing to address these issues can lead to much bigger (and more expensive) problems. Contact a local professional for advice if you notice any of the symptoms discussed in this blog post.

In this article, we have been through the advantages and disadvantages of concrete underpinning, whether or not resin injection is as good as traditional underpinning, and whether underpinning can fail. In summary, though it has its drawbacks, underpinning is a sound method for foundation repairs on strip footings and slabs and is much more reliable than resin injection underpinning.

How Long Does It Take To Underpin A House?

On average, it will take 1-2 weeks to underpin a house. The bigger the size of the building, the more time it will take to complete underpinning of a house. Larger projects can take up to 4 weeks.

This article will discuss the time required to underpin a house, the foundation repairs process behind it, and whether underpinning can damage your property.

How Long Does Underpinning Take?

Underpinning a house can take approximately 2 weeks. For larger homes, it can take up to 4 weeks. The process of underpinning a house is not complicated, but it is time-consuming.

What Is The Process Of Underpinning A House?

The process of underpinning a house starts when underpins are around the affected area of the foundation right after completing engineering. Trenches are dug below the footing, and steel-reinforced concrete is poured about 300mm below the existing footing into the trenches to create support for the building’s footing. These new concrete pins need to cure for at least 24 hours before the next step can be started.

Next, the building is ‘jacked up’ or raised using hydraulic jacks placed between the new concrete pads and the existing footing. Once the desired height has been reached, the gap is filled with concrete to complete the new underpin. 

The same steps are repeated for the next underpin until the project is completed. 

Underpinning is one of the foundation repairs processes that add extra footings or supports to your house in order to arrest foundational movement affecting the building’s structure. The goal of underpinning is to set your foundations on a more stable, sturdy, stronger, and less prone-to-move foundation.

Do You Have To Move Out During Underpinning?

No, you don’t need to move out during underpinning. In some cases, you may need to move out if there are internal walls affected, but for the most part, you will not need to leave.

If done by a professional, it’s safe to stay in the house but make room to work for the workers.

Will Underpinning Cause Damage To My Home?

Underpinning will not cause any damage to your home in most instances. However, if renovation has been performed, the process of lifting or jacking the building may cause cracks to appear inside the property. We recommend you discuss this with your chosen underpinning contractor. 

There are some disadvantages of underpinning. If you would like to know more, check out this blog.

How Often Do You Need To Underpin A House?

You only have to underpin a house once every several decades. Once you have an experienced underpinning technician underpin your home, you should not need to underpin your home again.

Concrete underpinning can last for many years, but you can’t guarantee results for resin underpinning. So, choose your underpinning method wisely to avoid further foundation repair work.

Do I Need To Underpin The Whole House?

No, you don’t need to underpin the whole house in most cases since only a section of it is usually underpinned. However, more underpinning can be required in homes more affected by subsidence and foundational movement. 

Underpinning a house is a process that can provide your home with more stable soil and a stronger foundation. In this blog post, we have discussed what underpinning is, how long it takes, and whether you need to move out during the process. If you are considering having your home underpinned, contact a professional for advice and guidance.

What Are the Stages of Underpinning?

The following are the stages of underpinning:

  • Excavation: The area surrounding the foundation is dug to create cavities.
  • Preparation: Concrete is poured in a hole under or around the foundations, and formwork is placed.
  • Reinforcement: The concrete is poured into the form, and let set or piles are driven into the ground until anchored.

What Is Resin Injection Underpinning?

Resin injection underpinning is a foundation repair process where resin is injected into the ground. The approach fills gaps along its path and hardens them to create a firm foundation. The process is used as an alternative to concrete underpinning, where small holes are drilled to inject resin into different layers of the foundation. If you are planning underpinning in Adelaide, check out this blog.

In this article, we will discuss whether it’s a good idea to use resin underpinning and what are the advantages or disadvantages of using this method.

How Long Has Resin Injection Underpinning Been Around?

Resin injection underpinning has been around for more than 30 years. It is the newest technology, but the effectiveness of the process is questionable. The process was first used in Europe and has slowly made its way to other countries.

If you want to know how long does it take to underpin, check this blog for more info.

What Are The Disadvantages Of Resin Injection Underpinning?

The following are the main disadvantages of resin injection underpinning:

  • Once done, it can’t be corrected, and no re-engineering possible.
  • You can’t install concrete underpins where resin underpin has been performed.
  • The resin can enter cracked pipes, filling up underground services with solid resin.
  • It is more expensive than other methods, such as concrete underpinning.
  • It is not as durable as concrete.
  • You can’t measure how much resin you need to fix the error as you can’t see beneath the earth.

What Are The Advantages Of Resin Injection?

The main advantages of resin injection are:

  • It is less intrusive than concrete underpinning, so there is no need to excavate around your property.
  • The process is faster, so you can move on with life more quickly.
  • It can be used in areas where concrete underpinning can’t be used, such as near trees or internal walls.
  • It’s good for pathways, small patches, and internal walls if they are not heavy load-bearing.

Is Resin Injection Underpinning As Good As Concrete Underpinning?

No, resin injection underpinning doesn’t perform as well as concrete underpinning. It is not as strong or durable and can’t be used in all situations.

If you want to know the difference between restumping and underpinning, check this blog for more details.

The “Botox Of Underpinning”

Resin injection underpinning has been called the “botox of underpinning” because it is a quick fix that doesn’t always last long. Many engineers believe it is not a permanent solution and should only be used in cases where concrete underpinning can’t be used.

If you’re considering resin injection underpinning for your foundation repair, consult a structural engineer or local foundation contractor to see if it’s the right choice for your situation. There are many other options out there that may be better suited for your needs.

How Does Resin Injection Underpinning Work?

Resin injection underpinning works by drilling small holes around the foundation and filling them with eco-friendly resin. As the substance expands, it lifts the foundation and compresses the surrounding soil to prevent future expansion or shrinkage. The injection of additional resin gradually raises the house.

Compared to concrete underpinning, resin injection is a speedy procedure requiring little excavation. However, if a large gap exists underground, requiring a significant amount of resin to fill it, resin injection may not be cost-effective.

What Is the Difference Between Restumping and Underpinning?

The main difference between restumping and underpinning is that restumping only replaces the stumps that are causing structural problems while underpinning involves adding more support to the existing foundation. The other main difference is that restumping is performed when the footing system is made from stumps, whereas underpinning is when the footing is a slab or strip footing. 

In this blog, we’ll discuss how restumping and underpinning work, whether a building is built on stumps or slabs, and how to tell for your property. Always consult licensed underpinning contractors before attempting to rectify foundation issues. 

What Is Underpinning?

Underpinning is a foundation repair process where a building’s footing is reinforced using steel-reinforced concrete pads. It can only be done if the structure is on a slab or a strip footing.

What Are the Different Underpinning Methods?

The different underpinning methods are:

  1. Traditional concrete Underpinning
  2. Piling Underpinning
  3. Micro-piling Underpinning
  4. Screw piles Underpinning
  5. Jet grouting Underpinning
  6. Resin injection Underpinning

You always need to consult authorised underpinning contractors to inspect your site and suggest what is best for your house.

What Is Restumping?

Restumping is the process of replacing damaged home stumps with new ones. Three types of stumps are available in the market — timber, concrete, and steel. Timber is the cheapest among all three yet more prone to damage, while concrete and steel are more expensive and durable.

Is Underpinning The Same As Restumping?

No, underpinning isn’t the same as restumping. They are two different foundation repairs used on two different types of footing systems.

Underpinning is done on the structure built on a slab while restumping can only be done on buildings that have stumps.

How Do I Know If My House Is Built On Stumps?

You will know if your house is built on stumps by noticing the following:

  • The structure is suspended above the ground.
  • You can see steel, concrete, or timber stumps underneath your subfloor.
  • There are vents around the perimeter of your home.

How Do I Know If My House Is Built On A Slab?

You will know if your house is built on a slab if no stumps are visible under your subfloor and your house isn’t elevated above ground level.

If you want more information about foundation problems, you can check our blog why do building foundations fail.

If you don’t know whether your home needs restumping or underpinning, this blog will help you. We’ve explained the differences between each repair process and how to determine which one is right for your home. We also recommend using a licensed professional to complete any restumping or underpinning work. With their experience and expertise, they’ll be able to properly assess your home’s needs and provide a solution that will stand the test of time.

What is the Difference Between Reblocking and Restumping?

There is no difference between reblocking and restumping. These two terms basically mean the same. Reblocking and restumping refer to the process of replacing the old foundation blocks or stumps of a house with new concrete stumps. This procedure is primarily applicable to older weatherboard houses that are elevated from the ground and have foundations.

Why Do Building Foundations Fail?

Building foundations fail because of subsidence and reactive soils. However, there are other factors and causes of subsidence.

In this article, we will discuss why building foundations fail, what subsidence is, the causes, and go through different underpinning methods.

What Is Subsidence?

Subsidence is the ground surface shifting downward caused by natural and man-made processes. In many cases, this subsidence is caused by reactive soils – that is, soils that expand and contract in response to changes in moisture levels.

What Are The Signs Of Subsidence In A House?

The most obvious sign of subsidence in a house are cracks on internal and external walls. However, keep an eye on the following types of cracking:

  • Step cracks that are spread across the wall diagonally
  • Cracks are visible both inside and outside of the wall bricks
  • The diameter of the crack is 3mm+
  • Cracks at the corners of doors and windows
  • You found cracks after long, dry weather.
  • Cracks are found close to the joints or extension

However, remember that just one crack in the wall does not always indicate a subsidence issue. Many less serious reasons for cracks to appear, including the walls or ceilings of your home, are due to swelling and contracting over time to temperature fluctuations. 

How Do You Fix Subsidence?

You can fix subsidence by underpinning the foundation of your property where it’s strengthened or rebuilt. The choice of underpinning technique will be influenced by several factors, such as the type of building, its age and condition, the nature of the ground, the water table level, and the importance of maintaining the stability of adjacent structures.

What Are the Types of Underpinning?

There are mainly two types of underpinning techniques:

Concrete Underpinning

Concrete underpinning is the process of excavating around sections of the building’s perimeter and pouring a concrete foot to support the foundation. Though this technique is very effective, it is unsuitable for every foundation type.

Screwpiling

Screwpile underpinning is another tool in the tool belt of foundation repair. This process drives steel screw piles into the ground to support your home’s foundation. Though it comes at a higher cost, it’s very effective for reaching deeper, more stable earth. 

Now you know about underpinning, you may be wondering what the difference between reblocking and underpinning is. This article answers those questions. 

Can You Permanently Fix Subsidence?

You can permanently fix subsidence by getting underpinning. However, please keep in mind that nothing will last forever. Most foundation repair or underpinning contractors will guarantee their work for at least 10 years.

Does Underpinning Stop Subsidence?

Yes, underpinning can stop subsidence. For example, when pouring concrete into the part of the foundation where the subsidence occurs, the surrounding soils become stronger enough to support the footing. As a result, it stops the subsidence for a long time.

No matter how well they are constructed, all buildings will eventually experience some form of foundation failure. While the reasons for this failure can vary, the most common cause is subsidence – or the sinking of the ground on which the building stands. Other causes of foundation failure include settlement (caused by a change in the weight of the building or its contents), earthquake damage, and improper construction. No matter what the cause is, if you notice subsidence, always contact a foundation repair contractor or structural engineer to inspect the damage and take their advice.

What is a Good Example of Foundation Failure?

A good example of foundation failure is the Leaning Tower of Pisa. This structure came to bear its name because of the unstable soil and a severely shallow foundation. Fortunately, this building continues to stand until this day.