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Australia
Understanding Foundation Issues
Your foundation holds your house together. When it’s compromised, it can affect everything from walls and floors to plumbing and safety. Knowing what to look for early can save you a lot of money.
You might need a foundation repair if you notice:
Interior Signs
- Cracks in drywall, especially around doors/windows
- Doors or windows that stick, won’t latch, or are out of square
- Uneven, sloping, or sagging floors
- Gaps between walls and ceiling/floor
- Nails popping out of walls
Exterior Signs
- Stair-step cracks in brick or masonry
- Separation between bricks/mortar
- Gaps around window/door frames
- Chimneys leaning or separating from the house
Basement/Crawlspace Signs
- Cracked or bowing foundation walls
- Water seepage or moisture
- Mould, mildew, or musty smells
- Sagging crawlspace beams or piers
Types of Foundation Problems & How to Fix Them
Cracks in the Foundation
Hairline Cracks (Cosmetic)
- Usually from concrete curing or minor settling.
- Fix: Use polyurethane or epoxy crack filler. Clean the crack, apply filler, smooth it out, and seal it.
- DIY-Friendly: Yes
Large Structural Cracks (>1/4” wide or growing)
- Often due to shifting soil or settling.
- Fix: Requires evaluation by a structural engineer. Could involve rein injection, underpinning, or rebuilding sections.
- DIY-Friendly: No
Settling or Sinking Foundation
Caused by soil shifting beneath your home, often due to poor drainage, drought, or expansive clay soil.
Repair Options:
- Piering (Underpinning):
- Steel piers are driven into bedrock to stabilise the structure.
- Helical piers are screwed into stable soil.
- Mudjacking (for slabs):
- Concrete slurry pumped under slab to raise it.
- Less stable than piers but cheaper.
Bowing or Buckling Basement Walls
Usually from hydrostatic pressure (water-saturated soil pushing in).
Repair Options:
- Carbon Fibre Straps: Bonded to wall to prevent movement.
- Steel I-Beams: Installed vertically against walls for added support.
- Wall Anchors: Anchored into soil outside to pull walls back.
Moisture & Drainage Issues
Water is the most common enemy of foundations. Poor grading, gutter problems, or broken drain pipes can lead to water pooling and foundation damage.
Fixes:
- Improve Grading: Slope soil away from house.
- French Drain Installation: Redirect water from foundation.
- Install/Repair Sump Pump: Keeps basement/crawlspace dry.
- Gutter Maintenance: Extend downspouts at least 6 feet away.
- Waterproofing Membrane: Applied to foundation exterior.
Foundation Heave (Upward Movement)
Opposite of settling — caused by expanding soil, usually due to moisture changes.
Fixes:
- Slab Replacement: In severe cases, entire sections may need to be replaced.
Mainmark provides the following in Australia: wall crack repairs, sinking floor repair, Concrete slab repair, sinking foundation repair, underpinning, ground improvement, re-levelling, subsidence repair, void filling and slab lifting
Identifying subsidence
Subsidence is not without warning signs. Some of the most common include:
Internal cracked walls
Wall cracks are common in homes and are often the first sign of foundation subsidence. Inside the house, they appear like steps in the brickwork/blocks or tiles and typically follow mortar or grout lines. The mortar and masonry deteriorates over time due to the movement of the affected wall.
Sinking floors
A concrete floor slab within a home can sink due to weak ground or subsidence. A building can sink at various localised points or can be spread across the entire footprint of the house foundation.
Jammed doors
Doors that don’t open smoothly, have uneven gaps or rub against frames are often a first indication of foundation damage
Exterior cracked walls
Step wall cracks are common in homes and are often the first sign of foundation subsidence. The mortar and masonry deteriorate over time due to the movement of the affected wall. Wall cracks are usually of concern when one side of the wall is higher than the other or cracks are wider than about 5mm.
Sinking & uneven concrete slabs
Sinking and uneven concrete driveways or path slabs can be an indication of unstable ground due to voids beneath the surface. If there is noticeable soil building up around slab joints, the concrete slab can start to crack around the edges as weight is exerted where there is no ground support.
Articulation joints
Usually visible in building extensions where two walls join and in modern buildings at the sides of large window and door openings. The gap is often wider at the top of the joint, exposing the lining.
Features & Benefits
Mainmark’s Solutions & Technologies For Re-levelling Foundations
Fast
Our technologies have fast curing times and treated areas can be used immediately or without the delays compared to traditional repair methods.
Environmentally Inert
Our technologies use an inert material that is non-toxic and does not leach into the environment or affect the treated area.
Non-Invasive
Our solutions are of surgical nature compared to traditional methods.
Cost-Effective
Compared to traditional methods, our solutions are more cost-effective, with minimal disruption to the area.
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Mainmark Ground Engineering Pty Ltd
ABN: 51 606 182 503
