How much does foundation repair cost?

Most foundation repairs range from $4,000 to $16,000, depending on the extent of the damage and the size of your property.

How long does the repair take?

Most foundation repairs are completed in just 1-2 days using our GeoPoly™ resin injection method.

What is GeoPoly™ resin injection?

GeoPoly™ is a high-strength expanding resin that we inject beneath your foundation. As it expands, it fills voids, compacts loose soil, and lifts your foundation back to level.

Will you need to dig up my yard?

No! We drill small holes (about 16mm diameter) through your slab or beside your footings, inject the resin, and patch the holes. No excavation required.

What does the 20-year warranty cover?

Our 20-year structural warranty covers the repair work we perform. If any issues arise with the repaired area due to workmanship or materials, we'll fix it at no additional cost.

Is the assessment really free?

Yes, 100% free with no obligation. Our structural engineer will inspect your property, explain the issues, and provide recommendations.

I’m planning to replaster—should I get the cracks checked first?

It depends on what’s causing them. Hairline cracks from normal settling or temperature changes are cosmetic—a good plasterer can deal with those. But wider cracks, cracks that follow staircase patterns through the mortar joints, or cracks near doors and window frames often point to structural movement in the masonry behind the plaster. If that’s the case, replastering over the top will look great for a while, but the cracks will come back. Our free structural assessment takes the guesswork out—our engineers will tell you exactly what’s going on before you commit to any work.

What’s the difference between replastering and a structural repair?

Replastering—whether it’s a skim coat, a full render, or patching with filler—covers the surface. It can make a cracked wall look perfect. But if the brickwork behind the plaster has shifted, the wall is still cracked underneath. As the structure continues to move, the new plaster cracks in the same places. A structural repair with HelicalBar™ fixes the masonry first—reconnecting the separated sections of wall with stainless-steel bars bonded into the mortar joints. Once the structure is stable, we replaster over the top. You get the same beautiful finish, but this time the wall behind it is actually holding together.

How does HelicalBar™ fix cracked plaster and internal walls?

Small, precise slots are cut through the plaster and into the mortar joints of the masonry behind. Stainless-steel HelicalBars™ are then bonded into those slots with high-strength structural grout. This reconnects the separated sections of wall at depth, so the structure carries load as one piece again. Once the bars are in, the wall is replastered to a smooth, paint-ready finish — in most cases, you'd hardly know the repair is there.

Do you repair the plaster finish as well, or just the structure?

Both. Every plaster wall repair includes full repair of the surface finish. After the HelicalBars™ are installed, we fill the cracks, apply a smooth skim coat, and leave the wall paint-ready. For heritage and older homes, we use gypsum plaster rather than rigid cement render — it's more sympathetic to the original construction and far less likely to crack again.

Can you repair cracked walls in heritage and older homes without damaging their character?

Absolutely—that’s one of the main advantages of HelicalBar™. The repair is completely concealed within the mortar joints. There are no visible fixings, no steel plates bolted to the wall, and no bricks or plaster removed. Our technicians take great care to closely match the plaster finish to the existing surface so the repair blends in. We’ve worked on homes over 150 years old—in most cases, the repair is barely noticeable.

What about ceiling cracks—can you fix those too?

Yes. Ceiling cracks—especially where the ceiling meets the wall, or cracks that run across the middle of a ceiling—are often caused by the same structural movement affecting the walls. If our assessment finds the ceiling cracking is structural, we address the root cause in the walls and then repair the ceiling plaster to a smooth finish. If the cracking is purely cosmetic (thermal movement in the plaster itself), we’ll let you know and you won’t need a structural repair.

I’ve noticed gaps at my skirting boards—is that related to wall cracks?

Often, yes. Gaps between the skirting board and the wall or floor are a common sign that the structure has moved. When the ground beneath a house shifts—from reactive clay, poor drainage, or foundation settlement—the walls and floors move slightly apart. Our free structural assessment will tell you whether the gaps are linked to structural movement and whether a repair is needed.

How much does plaster wall repair cost?

Every home is different, so we provide a fixed-price quote after your free structural assessment. The cost depends on the extent of the cracking, the number of walls affected, and the root cause. There are no hidden costs or surprise charges — the price we quote is the price you pay. Most homeowners find HelicalBar™ repairs significantly cheaper than traditional methods like partial knockdown and rebuilding.

How long does a plaster wall repair take?

Most residential plaster wall repairs are completed in one to two days, depending on the number of cracks and walls involved. Larger jobs—such as a whole-house repair across multiple rooms—may take a few days longer. Our engineer will confirm the expected timeframe during your free assessment.

Can plaster cracks come back after a HelicalBar™ repair?

HelicalBar™ is an engineered structural reinforcement—not a cosmetic patch. The stainless-steel bars reconnect the masonry at depth and redistribute load across the wall, so cracks are very unlikely to return. That said, every structural crack we repair is backed by our 20-year warranty. If any repaired crack reappears within that period, we’ll return and fix it at no cost to you.

Cracked Plaster or Internal Walls?

Find the cause, fix the structure, and skim-coat your walls for a good-as-new finish — guaranteed for 20 years.

Free quote · 1–2 day repair · 20-year warranty
Structural Engineers · Licensed Builders · Skilled Technicians

Cracked Plaster or Internal Walls?

Find the cause, fix the structure, and skim-coat your walls for a good-as-new finish — guaranteed for 20 years.

Free structural assessment with a fixed-price quote
Cracks repaired structurally — plaster finished ready to paint
Backed by a 20-year structural warranty

Qualified Engineers · Licensed Builders

15,000+Homes Repaired

20-YearStructural Warranty

1–2 DaysMost Repairs

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Engineered to repair your plaster walls structurally.

Non-Invasive. Stronger. Guaranteed.

No need to strip and replaster — save thousands.

If cracks keep coming back and you're thinking about replastering, think again. The wall behind the plaster is moving — no amount of replastering will fix that. This isn't just mending walls. It's reinforcing them permanently.

Neat channels are cut through the plaster, stainless-steel HelicalBars™ bonded into the centre of the brickwork — where it's toughest — and fixed in place. That's it. Most of your existing plaster stays intact.

Our plasterers finish the wall with gypsum plaster — the best finish for older homes. Your walls look new. And you've saved thousands by not having to strip and replaster.

Want to know exactly what your home needs? Get in touch for a free, no-obligation structural assessment.

What to expect

Here’s how we repair your home’s plaster wall cracks, from first visit to warranty.

Buildfix structural engineer assessing cracked plaster wall with tablet

Step 1

Free Structural Assessment

Our structural engineers assess the cracked areas, identify the root cause, and design a tailored repair. Repair details — with photos, markings, and measurements — are created on-site using our mobile software, and the price can usually be explained there and then, so you know exactly where you stand.

Buildfix quote package showing structural repair detail, quote cover page, and repair method statement

Step 2

Get Quote and Book

You receive a complete quote package including detailed drawings, repair method statements, and a fixed-price quote — so you’ll know exactly what it’s going to cost. When you’re ready, book through our online portal (takes about 5 minutes) and we’ll organise suitable dates for the work.

Buildfix technician installing stainless steel HelicalBars into mortar joints behind plaster wall

Step 3

HelicalBar™ Installation

On the scheduled day, our technicians arrive and get straight to work — cutting precise slots through the plaster and into the mortar joints behind, then bonding stainless-steel HelicalBars™ with high-strength structural grout. This reconnects the cracked structure at depth, tying separated sections of wall back together so they work as one piece again.

Smooth plaster wall finish after HelicalBar crack repair

Step 4

Replaster & Finish

Once the HelicalBars™ are locked in, we repair the plasterwork over the top. Cracks are filled, surfaces are skimmed smooth, and the wall is left paint-ready. For heritage homes we use gypsum plaster rather than rigid cement render, so the finish is sympathetic to your home's original character. When we pack up, you'd hardly know we were there.

Buildfix 20-year structural warranty badge

Step 5

Receive Your Warranty

After the work's done and signed off, you'll receive your Completion Package a few days later — a report covering the work carried out, materials used, and images from the process. It also includes your invoice with links to pay through our portal, and your warranty documentation.

See the difference

Actual HelicalBar™ projects where cracked plaster walls are left in near perfect condition.

Heritage room with severe plaster cracking exposing brickwork before and after HelicalBar repair

Cracked plaster around arch window before and after concealed structural repair

Plaster cracks around window frame before and after permanent repair

Hallway wall and ceiling cracks before and after plaster restoration

Internal wall with peeling plaster and ceiling damage before and after repair

Stairwell plaster cracks before and after smooth replastering

Exterior render cracks on building facade before and after repair

Structural fix.
Guaranteed to last.

The benefits of a HelicalBar™ plaster wall repair.

HelicalBars™ are bonded into the centre of the brickwork — where it’s toughest — through neat channels in the plaster. This isn’t just mending the crack. It’s reinforcing the wall permanently, reconnecting the cracked structure so it works as one piece again.

Plastered wall cross-section showing HelicalBar stainless steel bars stitching a crack through rendered wall

Real homes. Real results

See how we’ve helped homeowners fix their plaster wall cracks.

Why choose Buildfix?

Buildfix brings qualified engineers, licensed builders, skilled trades, and the manufacturer together under one roof. One team accountable for every step — from assessment to final sign-off. For nearly 15 years, we've been delivering non-invasive structural repairs — saving homeowners the hassle and costs of traditional methods. What used to take weeks now takes just 1 to 2 days.

Here’s why homeowners choose us

20-year structural warranty: Every repair is backed by a 20-year warranty — transferable if you sell your home.

Under one roof: We assess, design, repair, and manufacture — no need to deal with multiple contractors, because we handle it start to finish.

Fixed pricing, honest advice: No surprises, no tricks — just one fixed price from the start that never changes.

Non-invasive technology: Every method we use is non-invasive — less mess, less stress, and most repairs done in 1 to 2 days.

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Questions?

Our team is here to answer any questions you may have Monday – Friday 8am to 4pm AEST. Give us a call on 1300 854 115.

Cracked Plaster or Internal Walls?

Cracked Plaster or Internal Walls?

Don't take our word for it

Engineered to repair your plaster walls structurally.