Insist on a Waffle Slab for a Safer and More Stable Home

by Carlisle Homes


A stable home that stands the test of time starts from the ground up. Learn why having the right foundation matters.


The type of earth you lay your foundations on will impact your house for decades. By choosing the right foundation (or slab), you can prevent serious issues such as cracking walls, sinking floors and shifting piers. 

Melbourne’s soil tends to be highly reactive, which means it contracts and expands significantly in response to periods of wet and dry, which can destabilise your home. To stop this happening, you’ll need to lay a H1 class waffle slab, which gives your home a higher level of reinforcement.


For all new Carlisle homes*, we offer an H1 class waffle slab as a standard luxury inclusion.

At Carlisle, we give you the right foundation from the start. With our current promotion, if your new home requires an H1 class waffle slab, we’ll offer this upgrade to you at no charge. This provides your home with long-term protection and can mean thousands in savings!

Read on to learn more.


What is reactive soil?

Reactive soil refers to the way the soil reacts to moisture. Soil classification ranges from A class (non-reactive) to ED class (extremely reactive). 

The greater the soil reactivity, the greater the possibility of excessive movement. While a building can tolerate some degree of earth movement, if it’s excessive it can lead to walls cracking, floors sloping, gaps developing in your windows and doors, and a host of other structural problems. 


How reactive is Melbourne soil?

Regional parts of Melbourne typically have clay soil (unlike metro Melbourne, which has mostly sand soil). Clay soil generally falls towards the upper end of the scale and is classified as H1 class – highly reactive. This means the earth beneath a home in regional Melbourne can shift considerably with changes in moisture. 

Once your home is titled and there is access to your site, we will organise for a geotechnical engineer to conduct a soil assessment and confirm your soil reactivity classification.


Choosing the right foundation (or slab) can prevent serious issues such as cracking walls, sinking floors and shifting piers.

Which type of foundation is best for my home?

Homes with a H1 soil reactivity classification require a H1 class foundation, which provides significantly more support than a standard M class foundation to ensure your home isn’t affected by movement in the earth. 


Save with Carlisle’s latest offer.

At Carlisle, we don’t believe in hidden costs. 

Many Melbourne builders will only offer a standard M class foundation with their base price and then ask you to fork out thousands more for the right foundation to suit Melbourne's soil conditions. Fortunately, Carlisle has you covered from the get-go – no nasty surprises, only great savings. 

With our More Luxury* promotion, if your new home needs to upgrade to an H1 class waffle slab, we’ll supply it at no extra cost. This gives you the confidence of knowing your property is built on the right foundation from the start, without making a huge dent in your budget.


Waffle slabs are an innovative and cost-effective construction solution and one of the most popular slab types for new homes throughout Australia.

What is a waffle slab?

A waffle slab is a system of reinforced concrete footing and a slab. It consists of perimeter footing (or ‘edge beam’) with multiple strip footings (or internal beams), positioned one metre apart. The voids are filled with polystyrene. 

Waffle slabs are an innovative and cost-effective construction solution and one of the most popular slab types for new homes throughout Australia. 


What else is good to know?

Some soil conditions will require additional supports, such as bored piers or screw piles, to keep a home stable. If that’s the case for your home, this will be confirmed in your soil report.  


When will my soil be tested?

If you’re building a new home, once it has been titled and there is access to the site, Carlisle will engage a geotechnical engineer to assess your soil and produce a soil report.

The timing is slightly different for a knockdown-rebuild. An initial soil test will be undertaken pre-demolition, followed by a second soil report post-demolition – after which your soil classification and final site costs will be confirmed.

Learn more about our fantastic current promotions and how they can save you serious money here. Or get inspiration for your dream forever home with a visit to our display homes, conveniently located right across Melbourne.

*Find the terms and conditions of our More Luxury promotion here.


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