Lightweight Void & Trench Fill
Foamed Concrete Suppliers
Need to fill an awkward void, an old tank or a trench without the heavy lifting? Foamed concrete is the clever, lightweight answer, and Cardinalis Concrete mixes it fresh on your site across Cambridgeshire. It pours like a thick milkshake, flows into every corner and sets firm, with no poking, prodding or compacting needed. Whether it is a one-off job or a big commercial pour, we bring the mixer to you and get it done.
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State of the art
We use state of the art volumetric mixers.
5-star customer service
Expert help choosing the right mix.
24 hours a day
Flexible delivery to suit your schedule.
Our clients
Cardinalis Concrete
Foamed Concrete That Does the Hard Work for You
Some jobs are tricky. You have a hole, a gap or an old pipe that needs filling, but getting normal concrete into every corner is a real headache.
That is where foamed concrete comes in. It is a special lightweight mix that is full of tiny air bubbles, which makes it light, runny and very easy to place. It flows into spaces on its own and settles level without anyone having to compact it by hand.
Because we mix it right here on your site, you only pay for what you use, with nothing left over going to waste. It pairs perfectly with our concrete pumping service when the space is hard to reach, and it sits alongside the full range of mixes on our concrete delivery service. One phone call and we will sort the lot.
Sustainability Commitment
Mixing on site is better for your budget and better for the planet. Here is how we keep foamed concrete kind to the environment:
- We mix the exact amount you need, so there is no leftover concrete and no waste.
- We use locally sourced materials to cut down on travel and emissions.
- Our volumetric mixers only run the material you order, with nothing sent back to landfill.
- Lightweight mixes use less raw material than heavy concrete for the same space.
Light Enough to Float, Strong Enough to Trust
Cambridgeshire Foamed Concrete
Foamed concrete, sometimes called foam concrete or lightweight foamed concrete, is made by mixing a foaming agent into a cement and water slurry. This fills the mix with thousands of tiny air bubbles, which makes it far lighter than standard concrete. In some cases it can weigh less than half as much, which means it puts far less load on the ground below.
The big win is how it behaves once it is poured. It is self-levelling and self-compacting, so it flows into every nook, fills every void and finds its own level without any vibrating or tamping. That saves time, saves labour and gives you a clean, complete fill even in places you cannot easily reach. We can mix it at different strengths and densities to suit your job, from a soft, easy-to-remove fill right up to a firmer structural fill.
It also works brilliantly with a pump. Foamed concrete can be pumped over long distances and up or down to where it is needed, so tight sites and awkward access are no problem.
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when it's used
Applications for Foamed Concrete
Foamed concrete is a favourite on building and civil engineering jobs because it is so easy to place. Here are the jobs it does best:
- Void filling: filling old tanks, cellars, basements, disused sewers, pipes and other empty spaces so they cannot collapse
- Trench backfilling and reinstatement: filling trenches back in over pipes and cables, ready for the surface to go back on top
- Filling redundant pipes and ducts: sealing up old pipework that is no longer in use
- Lightweight fill: building up ground and levels where heavy material would push down too hard
- Under floors and around structures: filling gaps and hollow spots so floors and slabs have solid support
Because it is light and flows so well, it does jobs that normal concrete struggles with. When the space is hard to reach, our concrete pumping service can place it exactly where you need it. And if your job also produces spoil or old material that needs clearing, our grab hire and muck away service can take it away in the same visit.
Thermal Insulation Properties
Those tiny air bubbles do more than make foamed concrete light. They also trap air, and trapped air is a good insulator. This means a foamed concrete layer helps hold heat in as well as filling the space. The lighter, lower-density mixes hold the most air, so they insulate best, which makes them handy under floors and screeds where you want a bit of extra warmth as well as solid support.
Foamed Concrete
DENSITY VS STRENGTH
| Density (kg/m³) | Typical strength (N/mm²) | Best suited to |
|---|---|---|
| 400 to 600 | 0.5 to 1 | Thermal insulation and very light void fill |
| 600 to 800 | 1 to 2 | Void filling and insulating layers |
| 800 to 1,000 | 2 to 3 | General fill and trench reinstatement |
| 1,000 to 1,200 | 3 to 6 | Trench backfilling and sub-base fill |
| 1,200 to 1,400 | 5 to 8 | Stronger structural and load-bearing fill |
| 1,400 to 1,600 | 8 to 12 | Higher strength structural fill |
Areas we serve
Where we work
We cover all of Cambridgeshire and beyond, including:
Not on the list? Give us a bell anyway – we’re quite flexible with our coverage area for the right project.
c20 concrete
Frequently Asked Questions
It is a lightweight concrete made by mixing a foaming agent into cement and water. This adds lots of tiny air bubbles, which makes the mix light, runny and easy to pour. It is often used to fill voids, trenches and other awkward spaces.
It is used to fill empty spaces and voids, such as old tanks, cellars, pipes and sewers, and to backfill trenches over pipes and cables. It is also used as a lightweight fill and as an insulating layer under floors.
All those tiny air bubbles take up space where heavier material would normally be. This makes it much lighter, so it puts far less weight and pressure on the ground and structures around it.
It depends on the density. Lighter mixes are softer and easy to dig out again, while heavier mixes are stronger for load-bearing fill. Our density vs strength guide above shows typical figures, and we agree the right mix with you before we pour.
No. Foamed concrete is self-levelling and self-compacting. It flows into every gap and settles level on its own, so there is no need to vibrate, tamp or poke it. That saves a lot of time and effort.
Yes. It pumps very well and can travel long distances, which makes it ideal for tight sites and hard-to-reach voids. Our concrete pumping service can place it exactly where you need it.
Yes. The trapped air makes it a good insulator, so a foamed concrete layer helps hold heat in as well as filling the space. The lighter mixes insulate best.
It can. When mixed at a lower strength, foamed concrete is easy to break out again if the space needs to be reopened in the future. If you need a firmer, longer-lasting fill, we can mix it stronger to suit.
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Office hours
- Monday-Friday: 7:00am - 5:00pm
- Saturday: 7:00am - 12:00pm
- Sunday: By prior arrangement (we know deadlines don't always respect weekends!)
Or fill in our quick enquiry form here, and we’ll get back to you before you can say “concrete”!