[ Regional spotlight 09 ] Ipswich & Springfield // Owners & builders
Reality Capture in Ipswich and Springfield: Reactive Clay, Character Homes and New Estates
Reactive clay moves every year, and cracks follow. Learn what your AS 2870 site class means, and why a dated baseline turns a future crack into a comparison instead of an argument.
In this guide7 sections · 4 min read
// Module index · 07 modules
Ipswich is two building markets in one. The older suburbs around the city centre, Woodend and East Ipswich are full of character homes being restumped, raised and extended. To the east, Springfield, Ripley and the estates along the Centenary and Cunningham corridors are among the fastest-growing in Queensland, with whole streets of new slab homes going up at once.
What ties them together is the ground. Much of Ipswich sits on reactive clay that swells when it's wet and shrinks when it's dry, and that movement is behind a lot of the cracking, and a lot of the disputes, in homes across the city. This spotlight covers how site classes work, what to record before and after building, and how captures are booked. It's general information: your engineer, builder and soil report set what your build needs.
Building on reactive clay
Clay soils take up water in a wet season and give it back in a dry one. The ground rises and falls a little each year, most of all at the edges of a slab where the moisture changes fastest. Footings and slabs are designed for it, but anything that changes the moisture unevenly (a leaking pipe, a garden bed against the wall, a big tree, a long drought) can move one part of the house more than another. That's when cracks appear.
Some movement and some hairline cracking is normal on reactive sites. The hard part is telling normal from not, and old from new, after the fact.
What your site class means
Before a slab is designed, a geotechnical report classifies the site under the Australian Standard for residential slabs and footings (AS 2870). The class describes how much the ground surface is expected to move, from A for stable sand and rock to E for extremely reactive clay, with P for problem sites. Pick a class below to see what it means for the house and what to record.
Site class // reactive ground
Seven site classes. One baseline before the cracks.
Pick the site class on your soil report. The ground under the slab edges rises and falls with it, and the panel says what it means for the house and what to record.
Class A · Stable
Typical surface movementLittle or no movement
- What it means for the house
- Sand or rock. Ground movement is rarely the cause of cracking here, so look first at drainage, trees or the structure itself.
- What to record
- The condition of the house before nearby work starts: excavation next door can still affect it.
Class S · Slightly reactive
Typical surface movementUp to about 20 mm
- What it means for the house
- Clay that moves a little with the seasons. Most homes cope well, with only hairline cracks in dry years.
- What to record
- A baseline before building or renovating, so any later hairline cracks can be compared to it.
Class M · Moderately reactive
Typical surface movementAbout 20 to 40 mm
- What it means for the house
- Common across Ipswich and the new estates. Footings and slabs are designed for it, but drainage, gardens and trees near the house matter.
- What to record
- The slab and walls at handover, and existing cracks logged to scale with their position and width.
Class H1 · Highly reactive
Typical surface movementAbout 40 to 60 mm
- What it means for the house
- Clay that swells and shrinks enough to crack walls if moisture around the house changes unevenly, after a leak or a long dry spell.
- What to record
- A dated, measured baseline of every wall and floor, repeated after a wet or dry season if cracks appear.
Class H2 · Highly reactive
Typical surface movementAbout 60 to 75 mm
- What it means for the house
- Stiffer slabs and deeper footings, designed by an engineer. Moisture control around the house is part of keeping it sound.
- What to record
- The baseline at handover, plus floor levels, so movement can be measured rather than argued about.
Class E · Extremely reactive
Typical surface movementMore than about 75 mm
- What it means for the house
- The most reactive clays. Engineered footings are essential, and cracking is the usual source of disputes.
- What to record
- A full condition record before and after building, and before any nearby excavation, drainage or tree work.
Class P · Problem site
Typical surface movementSet by the engineer
- What it means for the house
- Not classed by reactivity alone: uncontrolled fill, soft soils, landslip, or old mine workings below. The engineer designs for the specific site.
- What to record
- The site and neighbouring homes before work starts, and the house as built, for a dated record if the ground settles.
Crack widths, roughly
- Category 0Under 0.1 mmHairline
- Category 1Under 1 mmVery slight
- Category 2Under 5 mmSlight
- Category 35 to 15 mmModerate
- Category 415 to 25 mmSevere
Simplified from AS 2870 guidance for masonry walls. An engineer assesses actual damage.
A dated, measured baseline turns a future crack into a comparison, not an argument. Ipswich is on our daily Brisbane Metro runs, and the class you picked is added to your request.
Cracks, disputes and the baseline
When a crack shows up, the first questions are always the same. Was it there before? How wide was it? Is it getting worse? Without a record, the answers come down to memory and a few phone photos without scale.
A capture gives a dated, measurable baseline of every wall, floor and ceiling. At handover, it settles the condition of the new house. Before nearby work, such as excavation, drainage, a pool or demolition next door, it records your home and the neighbours' homes as they were. If cracks appear later, they can be measured against the baseline instead of argued about.
Old mine workings and filled ground
Ipswich grew on coal, and parts of the city sit over old underground workings. Council keeps mapping of known areas, and some estates are built on filled ground. These sites are usually classed P, and the engineer designs for the specific conditions. A record of the site, the house as built and the neighbouring homes before work starts gives everyone a fixed point if the ground settles later.
Character homes in older Ipswich
Restumping, raising or building in underneath a Queenslander changes how it sits on the ground. Before the work starts, a capture records floor levels, the stump grid, every room and existing cracks to scale, and it gives the designer measured existing conditions for the extension.
Booking a capture in Ipswich
Ipswich, Springfield and Ripley are on our daily Brisbane Metro runs from Sunshine Coast HQ. For a new build, book the condition baseline at handover, and the pre-plaster frame audit as soon as you know the pre-line date. Every capture is architectural-grade, not a survey: levels for design and boundaries are work for a registered surveyor.
Nearby service areas: Brisbane heritage and basements · Logan new estates · every service area
Ipswich capture: FAQs
Q.01Where do I find my site class?
It's in the geotechnical or soil report done for your slab design, usually a letter and a short description. Your builder or engineer can give you a copy.
Q.02Are cracks in a new house on clay normal?
Some hairline cracking is common on reactive sites, especially after a wet or dry season. Wider or growing cracks need an engineer's assessment, and a dated baseline helps them see what's changed.
Q.03Can you record my house before the neighbours build?
Yes. A condition record of your home before excavation or demolition next door gives you a dated, measured reference if damage is claimed later.
Q.04Do you measure crack widths?
The capture records every crack visible at the time, with its position and length, and widths can be measured from it. An engineer assesses what the cracks mean.
Q.05How often do you come to Ipswich?
Daily, on our Brisbane Metro runs from Sunshine Coast HQ.