How Can I Prevent Foundation Problems In My Home?

You can prevent foundation problems in your home by ensuring its foundation is free from excess moisture. Things like stormwater, tree roots, and soil conditions are all elements that need to be managed. 

In this article, we will discuss what you can do to prevent foundation problems, the causes, and other precautions that can prevent foundation problems in your home.

What Destroys A Foundation?

The main reason a foundation becomes damaged or unstable is due to moisture. Check your water management system to see if you’re doing everything you can to keep water away from your foundation.

Secondly, tree roots can heave and damage foundations. Make sure to plant trees at a reasonable distance from your home, and keep an eye on the ones already there.

And finally, soil conditions can also lead to damage. So, if you want to get the best underpinning South Australia residents love, it’s important to be aware of the soil type around your home.

6 Tips To Avoid Foundation Problems

These are the six tips to follow so you can avoid foundation problems on your property:

1. Check Storm Water System

A faulty stormwater system can allow water to pool around your foundation and seep in, swell and heave. Make sure your storm water drains appropriately so it can carry water away from your foundation.

2. Replace Damaged Gutters And Downpipes

Gutters and downpipes that are in poor condition can also allow water to pool around your foundation. The amount of water in the soil around your home’s foundation affects the pressure on the foundation, which can cause it to collapse or shift. Check them regularly and repair or replace them as needed.

3. Beware Of Tree Roots

Tree roots can go considerably deep into the ground and out of sight. As a result, tree roots can suck moisture away from foundations and cause damage. It’s important to check for these problems and take action as soon as you notice them.

4. Don’t Plant Trees Near Buildings

Be sure to plant anything sturdier, like bushes or shrubs, in your flower beds. They should be placed at least two feet away from the edge of your home’s foundation. This will ensure that the roots and drainage go where they belong — away from the house.

5. Monitor Cracks In Home

Always check your foundation and keep an eye on your walls and flooring. If you notice any cracks, get expert help as soon as possible. This is the best opportunity to correct the damage and prevent further foundation movement. The earlier you detect foundation problems, the easier they are to fix. You already have a significant issue if you see large fractures or wall bowing in your home.

6. Consult A Professional

Finally, get a professional inspection if you notice anything suspicious about your foundation or just want a clear picture of your real risk for this kind of worry. They can tell you whether your foundation is in good shape. Also, they can give you a few tips for the best prevention measures in your region.

Suppose you notice anything unusual about your foundation. In that case, we recommend getting a professional inspection or wanting a clear understanding of your real risk for this worry. They will not just tell you if your foundation is in excellent condition, but they’ll also be able to of you some ideas on how to keep it that way in your area.

How Can You Differentiate Between Settling and Foundation Problems?

You can differentiate between settling and foundation problems based on the angle of the cracks that appear on walls over time. Vertical hairline cracks about 2 to 6 inches are normal while diagonal or horizontal cracks of any size indicate issues with the property’s foundation.

It’s essential to get help from a foundation repair expert once you start noticing cracks around your home that aren’t vertical in nature, no matter the size.


Underpinning is a complex process, and it’s simply not something an inexperienced person can do on their own. If you want to know more, check out our blog, “Can you DIY underpinning?” for more details.

By keeping a vigilant eye on your home, yard, and foundation, you may avoid the headache of a damaged foundation.

Can You Underpin A House Yourself?

Yes, you can underpin a house yourself. Unfortunately, most people lack the actual expertise to ensure a project is completed the right way. You shouldn’t consider DIY underpinning if you don’t have the equipment, proper experience and licencing. 

Are you wondering if it’s possible to underpin yourself? In this article, we’ll discuss whether it’s safe to underpin a house on your own, the dangers involved in doing so, and the benefits of hiring an expert.

Is DIY Underpinning A House Possible?

Yes, DIY underpinning is possible. However, it only works if you’re experienced, have the right skills, and are knowledgeable in completing the entire underpinning process successfully. If you lack any of the mentioned, we highly recommend not underpinning a house yourself.

Yet even if you have such expertise, it’s still best to consult an engineer. These professionals will provide you with proper advice in terms of pin placements and installations to avoid issues with your property later on. 

What Are the Risks of Underpinning a House Yourself?

The following are the main risks of underpinning a house yourself:

  • You can’t guarantee the workmanship
  • You may jeopardise the property’s structure 
  • Any mistake in the process can result in personal injury and permanent property damage
  • You could void your insurance policy
  • It may not meet compliance regulations

You can check out our other blog here if you want to know how to prevent foundation issues.

Why Should You Choose A Professional Underpinning Contractor?

You should choose a professional underpinning contractor based on the following:

  • They have the experience to handle any underpinning job correctly
  • They use the latest technology and equipment
  • They can provide a written guarantee
  • They are insured and licensed
  • They will comply with all building codes and regulations

If you are curious about does my house need underpinning, check out our blog here.

Is Underpinning Complex?

Underpinning is a complex process that involves excavating around a house’s foundation to a depth of several feet. Then, concrete piers are installed to support the weight of the structure. The entire process must be done carefully to avoid damaging the house’s structure.

Is Underpinning Dangerous?

Underpinning is dangerous because of the following reasons:

  • You can injure yourself if you’re not careful with heavy tools
  • DIY underpinning can lead to significant property damage
  • Overcorrecting relevel can worsen the cracks
  • DIY underpinning doesn’t comply with housing authority regulations and can void insurance

Does Underpinning Require Experience?

Completing an underpinning project requires experience. It should only be done by a professional underpinning contractor that has the proper expertise and equipment. Every project is different, and without relevant experience, you end up spending more money than required.

Is There a Warranty for Underpinning?

Yes, there is a warranty for underpinning but only if you work with an authorised contractor. The warranty will protect you in case of any issue with underpinning. Most underpinning contractors in Adelaide provide at least 10 years of warranty on underpinning.

We recommend using an expert foundation repair contractor always for any underpinning project. They have the experience, equipment, and resources to do the job safely and correctly. Choose a contractor that is insured and licenced and can provide a written guarantee.

What Materials Are Used in Underpinning?

The materials used in underpinning are poured concrete piers, bored piers, steel screw piles, and driven piles. The latter can be made of steel, concrete, or timber.

How Can I Tell If My Home Needs Underpinning?

You can tell when your home needs underpinning if you start noticing cracks in walls and when windows aren’t shutting or opening properly. These signs are good indications that your property needs underpinning.

In this article, we’ll discuss the signs your home may need underpinning and what you can expect from the process. This is what our team at Adelaide Underpinning Group recommends any client consider when looking at undergoing foundation repairs. 

What Are the Signs a House Needs Underpinning?

The following are the signs a house needs underpinning:

Cracks Are Visible on Walls and Corners

One common sign that a home needs underpinning is cracking in the walls and corners. It may be caused by foundation settlement when the soil beneath a home begins to shrink and settle. As the soil thins and compacts, the foundation can no longer support the weight of the home, leading to cracks in the walls and floors.

Windows Don’t Open and Close Properly

Windows that don’t close or open properly can also indicate that your home needs underpinning. This often happens due to foundation movement, which can occur when the soil around the foundation starts to move and shift. Foundation movement can cause the window frames to become misaligned and even lead to windows popping out.

Floors Are Not Level

Another sign that your home may need underpinning is if your floors are not level. This can be caused by settlement or erosion of the soil beneath the house. When the soil shifts, it can create uneven surfaces that can be dangerous for people walking on them. It can also lead to water infiltration and damage your home’s foundation.

If you notice any of these problems in Adelaide, it’s important to have them checked out by a professional like our team at Adelaide Underpinning Group as soon as possible. Failing to address a foundation issue can lead to much bigger (and more expensive) problems down the road.

Is It OK to Buy a House That Has Been Underpinned?

It is OK to buy a house that has been underpinned by a licenced contractor and is certified by a structural engineer. Otherwise, it might be risky and expensive (it might need rework or could lead to further damage). Keep in mind that it’s a technical yet physically demanding work and can’t be done on your own.

Check the potential risks by reading our blog “Can You DIY Underpinning?” for more details.

How Can I Tell If a House Has Underpinning?

You can tell when a house has underpinning based on the following:

  • If the edge of an exposed concrete foundation is visible at ground level, it indicates that the house has undergone underpinning. This occurrence, however, is quite rare since most edges of concrete foundations aren’t easily seen.
  • A surveyor can determine whether the property has undergone underpinning by evaluating whether the movement is active and ongoing or dormant and historical. They can also determine the extent of its severity, allowing them to confirm existing underpinning.

In case you are aware that the property has undergone underpinning, it is crucial to obtain all the necessary documentation. This should include a certificate issued by the structural engineer, confirming that the work has been carried out satisfactorily per the industry’s standards and that the house is structurally stable. It is advisable to review these documents carefully as they will provide insurance for the completed work.

Do I Need a Permit for Underpinning in Adelaide?

Yes, you will need a permit to underpin your home in Adelaide. There are some instances where a permit is not required, such as underpinning an internal wall, but this is better discussed with your underpinning contractor. Your underpinning contractor will also organise a geotechnical report known as a soil test and engineering to apply for the permit.
Underpinning is a process of stabilising and restoring the foundation of a house. It’s important to have your home checked for any signs of foundation failure by a certified contractor. For more details, you can read our other blog, “When Do You Need to Underpin?

What Is Underpinning And When Is It Needed?

Underpinning is a foundation repairs process used to reinforce the foundation of an existing structure where a slab or strip footing is used. This is done by extending the foundation to a deeper, more stable level to reduce and minimise foundational movement.

In this article, we’ll discuss what underpinning is, when you need it, and some different types of building foundations and footings. 

When Is Underpinning Needed?

Underpinning is needed when repairing or strengthening a foundation that has been damaged. It is also necessary when you need to increase the structural support for a building. Most experts would recommend underpinning when another story is added to a building or a renovation is taking place.

You should consider underpinning your house if:

  • It is built on reactive soils, and you’ve noticed movement
  • The fill under your foundation is not compacted properly
  • There is poor drainage around your foundation
  • You are planning to extend or renovate your house
  • You have cracks in your walls and floors
  • Your doors and windows are not closing correctly

If you see all or most of the above happening, you need to contact a local contractor who works on repairing foundations.

Types of Building Foundations and Footings

The different types of building foundations and footings are:

Slab on Ground

This is the most common type of foundation. It’s a concrete slab poured directly onto the ground. The soil underneath the slab must be compacted to provide a stable base. If the soil is not compacted correctly, it can settle over time and cause the foundation to crack or collapse.

Suspended Floors

Unlike a traditional floor, a suspended floor is not laid on the ground. Instead, it is connected to the ground by stumps or piers.

Continuous Footings

Continuous footings are used to support loads that are distributed evenly. They can be concrete strips or slabs. They are commonly used to support walls built on sloping sites.

Pad Footings

Pad footings are used to support loads that are not evenly distributed. They are usually concrete pads or piers that are commonly used to support columns, posts, and stairs.


Stumps are posts that support a house’s subfloor and are concreted into the ground. They’re commonly made of reinforced concrete but can also be steel or timber.


Piles are long, vertical steel or concrete sections that are driven into the ground. Piles are used to strengthen the foundation where the soil is not sturdy enough to support the weight of the house. Piles are usually used with a pad footing or a strip footing.


Piers are vertical structures that support a building’s beams. They are made from steel or concrete. Once the piers are set into the dug holes, it is reinforced with concrete to stay in place.

Why Do Building Foundations Fail?

Building foundations fail because of the following reasons:

Reactive Soils

Reactive soils are soils that expand and contract in response to changes in moisture content. This can cause the soil to heave or settle, damaging the foundation.

Poorly Compacted Fill

Suppose the fill under the foundation is not compacted correctly. In that case, it can settle over time and cause the foundation to crack or collapse.

Site Erosion

Erosion can also damage a foundation. When water washes away soil from around the foundation, it can leave the foundation unsupported and susceptible to damage.

What Are the Main Benefits of Underpinning?

The main benefits of underpinning are:

  • Enhanced Structural Integrity
  • Increased Property Value
  • Improved Ceiling Height and Lighting

Which Underpinning Method is Best for Me?

The best underpinning method for you is the one recommended by an experienced foundation repair contractor. This professional will inspect the surrounding, foundation, and footing of your house to identify the problem.

After that, they will brief you on what to do and the estimated cost and time. We have written a blog to give you an idea about the cost of underpinning, read this blog to get a clear picture.

Also, if you want to know more about underpinning, we have a blog explaining, “Does My Home Need Underpinning?“. You should check this out.

How Much Does It Cost to Underpin a House in Adelaide?

The average cost of underpinning a house in Adelaide ranges from $4,500 to $40,000. Larger projects with more involvement can cost up to $75,000. The price for underpinning depends on a number of factors, including the number of pins being installed, the method used, and access. 

In this article, we’ll go through the common methods of underpinning and what to look for when requesting an underpinning quote.

What Is Underpinning?

Underpinning is the process of reinforcing the foundation of a structure. This is usually done by excavating around the perimeter of the foundation and installing support beams or piers underneath.

Need to know more about what is underpinning? Check out this blog. 

What Are the Different Methods of Underpinning?

The following are the most common methods of underpinning:

Concrete Slab Underpinning

Concrete slab underpinning is the most popular method of underpinning in Adelaide. It involves excavating around the perimeter of the house and pouring a concrete footing to support the foundation. This method is quick, relatively inexpensive, and can be done without damaging the house. However, it is not suitable for all types of foundations.

Screwpile Underpinning

Screwpile underpinning is another method of underpinning that has become popular in recent years. It involves driving steel piles into the ground to support the foundation. This method is more expensive than concrete slab underpinning, but it is less likely to damage the house and can be used on all types of foundations.

What Should You Be Looking For In An Underpinning Quote?

These are the following things to look for in an underpinning quote:

Fixed Price Quotation

When receiving an underpinning quotation, be sure it is a fixed-price quote. This implies that the price quoted is permanent and will not fluctuate based on any unforeseen expenditures. Adelaide Underpinning Group always gives fixed price quotes, so you can be certain you’ll know precisely what you’ll pay.

Transparent Quotation

Underpinning quotes should be simple and jargon-free. If they’re not, seek clarification and double-check that you understand everything before going forward. Our team at Adelaide Underpinning Group uses plain English and is always available to answer questions by phone or email.

Fixed Time Frame

When getting an underpinning quote, it is important to ensure that the contractor can provide a work schedule that clearly outlines each stage of the process and how long it will take. They should also be prepared to work according to a fixed timetable, of course, depending on the weather. Adelaide Underpinning Group always provides a clear work schedule and timeline for each job, so you can be confident that the work will be completed on time.

How Risky Is Underpinning?

Underpinning is extremely risky when it is performed by someone who doesn’t fully understand its process. This type of work can be dangerous especially since it could damage a home or even lead to its eventual collapse.

That’s why hiring an expert underpinning contractor is best to ensure the whole process goes smoothly.

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.


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.