1800 18 20 20

Underpinning

With Over 50+ Years of Combined Experience, Rectify is The Leading Resin Injection Underpinning Team in Victoria, South Australia and Tasmania.

21st Century Technology for Underpinning

Over time, a dwelling may suffer from dropping foundations. The tell-tale signs of this include wall cracks, twisted door frames causing sticky doors, and sinking slabs.

Modern building design and slab foundations do not lend itself to traditional underpinning methods. Our solution is the modern answer to concrete underpinning.

Our method is minimally invasive without the need for mass excavation of soil and ripping up gardens and pavements beside the footing.

Traditional underpining is generally more costly, time consuming and does not always solve the underlying issue. It does not improve the ground conditions, and may create future complications for foundation performance.

What is Chemical Underpinning?

Also known as polyurethane underpinning is the process of injecting a 2-part resin under the affected area of the slab, causing a rapid expansion which fills any empty spaces (or voids) in the soil. This strengthens the soil and creates a strong base which ensures that the property will no longer sink. Using this solid base, more resin is then injected on top causing the property to lift back into the original position and returning it to a near new state.

Traditional concrete underpinning vs polyurethane underpinning

Traditional underpinning services use concrete and steel to reinforce the area under the slab. To achieve this, excavation is required. This creates a big mess, potential damage to the site by the excavation equipment and can take a long time to complete.

Unlike the methods used by most underpinning Melbourne companies, underpinning using chemicals such as Polyurethane is a less-invasive method and achieves a stronger outcome. 16mm holes are drilled in the ground under the slab for the resin to be injected having no contact with the existing footings. This process is cleaner, quicker and can be done in a considerably shorter period of time.

Causes of damage: 

  • Founding in Reactive Clay Soil:

    Clay soils has the ability to absorb or dispel moisture. In a wet environment, clay will absorb moisture increasing its plasticity and expanding. This causes heave in footings and structures. In contrast, in hot and dry environments, it becomes hard, brittle and non-plastic shrinking in the process. During periods of prolonged drought, the clay shrinks to the extent that the structure supported by it subsides significantly. Any other cause for loss of moisture in clay will cause subsidence and settlement, this includes trees and vegetation, or the construction of a new structure which affects the impermeability of soil beside structure.

  •  Flooding and water erosion:

    Poor site drainage can lead to water ponding against and seeping below a concrete structure, be it a house or a warehouse slab. The water weakens soil and washes away the silt/sands from silty and sandy clays. This leads to voids and weakening of soil causing subsidence. Cracked or leaking pipes (drainage or sewer) is another cause of poor site drainage. Therefore, we recommend regular checks of all pipes for any signs of leak.

  • Undermining or due to adjoining footing construction:

    If the adjoining land to your property is vacant, and during slab preparation your footing is undermined, that is the adjoining cut is below the bottom of your footing, this may loosen soil and cause subsidence.

  • Load exceeds concrete strength and soil bearing capacity:

    A 150mm thick concrete slab can typically support a weight of 860kg/m2. However, the soil supporting the slab can have less support weight/bearing capacity. Once a structure or another type of load, such as a heavy vehicle, overloads this limit, the concrete begins to weaken and cracks can begin to form and soil underneath starts to settle. This creates openings for moisture to enter; weakening the underlying soil. A crack that is 5mm wide has the potential to reduce the weight capacity by up to half of its initial strength.

  • Poor Workmanship and inadequate founding:

    Waffle slab footing (edge and internal beams can be supported on up to 300mmof ‘controlled fill’. The controlled fill has a strict method of laying, and is required to be of clayey materials with 97% of moisture. We recommend that all edge ribs are trenched through this fill and founded into natural clay. However, when the ribs are founded on fill, if it hasn’t been prepared as per requirements set out inAS2870-Residential Slabs and Footings, then the fill will settle over time and the slab will subside and show signs of distress.g you peace of mind

Whatever the cause, our underpinning services can help.

Step 1 - Site Investigation

A professional will do a site investigation to discover the reason for subsidence and any cracking so that we can ensure that the correct method of rectification is undertaken. If required, we will do a soil test to determine the soil profile and, by using the latest technology, we can track the site moisture and the full extent of subsidence beneath your home or property.

Step 2 - The Solution

After identifying the cause, we will provide you with the best rectification solution; including locations for injection to ensure slab correction and lift. We will then mark out the injection locations (both externally and internally) for our contractor to do a full survey of these points using a ground penetrating radar (GPR), locating all service cables/pipes to ensure that any existing services are not damaged.

Step 3 - Begin Injection Process

Once injection hole locations are confirmed as clear of existing services, 16mm holes are drilled approximately 1500mm deep at each injection location. This can either be in soil external to structure or internally. Ports are inserted to begin the chemical underpinning and injection process.

Step 4 - Finalise & Quality Check

Survey equipment is set up to monitor the lift process, to ensure adequate lift is undertaken. The injection process is started. Once finalised, the rods are cut, and holes re-grouted. Site is cleaned and any additional rectification works are complete.

1
A professional will do a site investigation to discover the reason for subsidence and any cracking so that we can ensure that the correct method of rectification is undertaken. If required, we will do a soil test to determine the soil profile and, by using the latest technology, we can track the site moisture and the full extent of subsidence beneath your home or property.
2
After identifying the cause, we will provide you with the best rectification solution; including locations for injection to ensure slab correction and lift. We will then mark out the injection locations (both externally and internally) for our contractor to do a full survey of these points using a ground penetrating radar (GPR), locating all service cables/pipes to ensure that any existing services are not damaged.
3
Once injection hole locations are confirmed as clear of existing services, 16mm holes are drilled approximately 1500mm deep at each injection location. This can either be in soil external to structure or internally. Ports are inserted to begin the chemical underpinning and injection process.
4
Survey equipment is set up to monitor the lift process, to ensure adequate lift is undertaken. The injection process is started. Once finalised, the rods are cut, and holes re-grouted. Site is cleaned and any additional rectification works are complete.

Why Choose Rectify?

With a combined total of 50 years experience on the job, we are registered residential and commercial builders, structural engineers, geologists, project managers, supervisors and technicians with an experienced admin team.

For residential structures we service Victoria, South Australia and Tasmania. For larger projects we service Nationally.

We pride ourselves on our customer service, so feel free to reach out and we will strive to provide you with industry leading experience.

Call us at 1800 18 20 20 today to find out more about our underpinning services—our team is always willing to have a chat to discuss your job.
Rating

5.0

35+ Reviews
Here's Why We Stand Out

The Rectify Advantage

Unrivalled Experience
We have a team of qualified structural engineers, geologists, project managers, supervisors and technicians with highest level of expertise and training.
Cutting-Edge Technology
We invest in the latest technology, equipment and materials, constantly reviewing latest developments from around the world
Quality Assurance
Our commitment is backed by the quality of our workmanship, offering a 10 year warranty across our services.
Seamless Delivery
Our non-invasive technique ensures you do not vacate your home or business, enabling continuity of use
Affordable Solutions
We ensure the solutions provided are affordable and competitive when compared to other similar companies
Environmentally Conscious
Low carbon footprint using less raw materials, reduced site traffic and excellent thermal insulation properties.
Our Testimonials

What our clients
are saying

Get in touch with the Rectify team today to begin work on your next project.
Rating

5.0

35+ reviews

Highly Recommended

Thanks to all the team - Frank, Armand, Adrian, Birt, Junior, Beyz and Tina - for the professional approach and expertise brought to a difficult four townhouse stabilization and lift project. Highly recommended.
Bill Rees
Verified Customer

Very Professional

Very professional. Explained everything to me and answered all my questions. The guys were always on time and cleaned up everything when they left, and they were friendly and polite.
Andrea Wilde
Verified Customer

Professional & Clear

Professional and clear advice, all services undertaken in a planned and timely manner. At the moment all seems well - but a bit early to confirm definitively
Cheryl Sullivan
Verified Customer

Beyond Expectation

We were very satisfied with all aspects of their service. The outcome was beyond expectation with all wall issue greatly improved. Their knowledge and service was great. Would highly recommend Rectify.
Kris Camm
Verified Customer

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