Eugene is a trained engineer and self-taught home improvement enthusiast with almost 40 years of professional and DIY experience.
Make Concrete Without a Mixer
A cement mixer does a great job at mixing concrete, thoroughly blending the materials to give a consistent result. However it's also possible to mix concrete by hand without a mixer with a little care and some effort. Sometimes the need arises to mix concrete for setting gate, fence posts or a clothes line into the ground. Another possibility is that you have to make a concrete slab to act as a base for something like a fuel bunker. All you need for mixing concrete are cement, stone, sand and water. Minimal tools are required: A shovel, a couple of buckets and optionally a sheet of plastic.
This is the first of a two part guide. My other guide shows you how to use a cement mixer for making concrete:
How Do I Mix Concrete? - 8 Easy Steps!
- Spread a plastic sheet on the ground.
- Measure out the materials.
- Place the stone and sand into a pile on the sheet.
- Place the cement on top of the pile of sand and stone.
- Shovel the material in the pile to one side, creating a new pile and repeat three times.
- Make a deep crater in the pile and add water.
- Fold the mix in from the sides.
- Continue to fold inwards and "chop" the pile to distribute water through the mix.
See below for lots more details and photos.
What is Cement?
Cement is a binder, used as an ingredient in combination with sand and stone (types of aggregate) to make a composite material called concrete. The three constituents on their own have no real strength but when bound together, stones interlock like a 3D jigsaw puzzle and sand and cement fills the gaps. Cement just glues the stones and sand together and without it, the latter would just slump and fall apart, but it's the stone that gives concrete its shear and compressive strength, not the cement.
There are several different types of cement, two examples are Portland cement and blast furnace slag cement. Portland cement is made by baking limestone in kilns and grinding the clinker produced with a little gypsum to form a fine powder. Blast furnace slag cement is made from the waste products of the steel industry.
Your Options - Pre-mix Concrete or Make Your Own
If you need to mix concrete by hand, there are two options:
- Buy a bag of pre-mixed concrete (drymix). This is available at all good home improvement stores. It has all the ingredients dry mixed together for making concrete, i.e. the cement, sand and stone. All you have to do is put it into a bucket, wheelbarrow or on a piece of plastic on the ground, add water and spend a few minutes mixing it. Usually the product comes in 2 to 4 stone bags ( 10 kg to 25 kg) with varied setting times. Quick setting concrete is available for fixing posts into the ground so that they don't have to be stayed.
- Mix your own concrete from sand, cement and stone. Premixed products from stores tend to work out much more expensive if you're going to need several wheelbarrows of concrete. The alternative is to mix your own. Ideally stone should be 30 mm (3/4"). Instead of sand and stone you can use ballast (mixed aggregate or "all in") which is a mixture containing varying sizes of particles ranging from sand to larger stones. Ballast can have a varying proportion of sand/stone, so you may need to judge whether you have to add additional sand.
Crushed stone is produced in quarries by crushing blasted rock and then the result is graded by being passed through a succession of sieves. In theory, this should make better concrete than rounded stone from gravel pits, because of the sharp angular edges.
Cement is generally available in 25kg bags. In the US it is sold in 47 or 94 pound bags
Materials Required and Concrete Mixing Ratios
Read More From Dengarden
A C20 mix consists of:
- 1 part cement
- 2 parts sand
- 4 parts stone
Alternatively, instead of sand and stone, a mix called ballast, mixed aggregate or "all in" can be used, and this is mixed 6 to 1 with the cement.
A stronger, more hard wearing C30 mix, suitable for thinner and narrower concrete slabs, e.g. pavements, consists of:
- 1 part cement
- 2 parts sand
- 3 parts stone
As in the case of the C20 mix, if you're using ballast (sand and stone), mix it 5 to 1 with the cement.
Ideally stone should be crushed and 15 to 20 mm in size (9/16 to 13/16 inches).
Sharp sand should be used, graded from 0 to 5mm. Don't use fine stuff which is really for mortar/plastering.
How Much Water For Making Concrete?
The amount of water needed to make concrete falls within a range of 0.4 to 0.5 times the weight of cement. So if we take a mid range figure of 0.5, then for a 25 kg bag of cement:
25 x 0.5 = 12.5 kg of water or 12.5 litres
This is 90% of the the volume of a 3 UK gallon (Imperial) bucket. Since the aggregate may be wet, this can mean that less water is actually needed, so these values are approximate.
The mix shouldn't be sloppy and should be able to self support itself without slumping. Concrete that is too dry is unworkable. Sloppy concrete due to excess water will be weak.
What Does C20 Mix Concrete Mean and is it the Same As M20?
It means the concrete can withstand a compressive force (or more correctly pressure) of 20 newtons per square millimetre (20 MPa) without crushing after a curing period of 28 days.
A testing rig is used to perform crush tests on samples of concrete.
The C20 standard specifies the use of a 15 cm diameter by 30 cm high cylinder.
The M30 standard specifies a 15 x 15 x 15 cm cube.
Tools and Equipment For Mixing Concrete
- Builders shovel. (The pointy type one)
- Ideally three, 3 gallon buckets. One for water, one for cement and one for sand/stone. If the sand or stone is wet and you use this bucket afterwards for measuring cement, it will stick to the sides and bottom.
- Polythene sheeting. A sheet of polythene helps to prevent mess and contamination of the concrete by pebbles, leaves, soil and other debris. It also makes it easier to scrape up all the leftovers with no wastage. I use 1200 gauge polythene (the heavy stuff used as a damp proof membrane under concrete) and this is widely available in hardware stores. You can of course mix concrete in a wheel barrow or bucket, but there's more room to mix on a sheet.
- Wheelbarrow or buckets. For transporting the concrete to its final destination. Alternatively you can mix in situ.
For laying concrete, you can use a garden rake or a 1 x 4 board nailed or screwed onto a length of 1 1/2 x 2 for spreading.
Do I Need to Wear Personal Protective Equipment (PPE) When Mixing Concrete?
- A dust mask will help to prevent the inhalation of fine cement dust while measuring out.
- Gloves to protect hands. Cement is somewhat caustic when dry, so if you have sensitive hands, these will give protection.
- Safety glasses stop cement dust or splashes of concrete from getting into your eyes
- Steel toe-capped boots. Optional. You may end up standing in or close to concrete while mixing/laying. Steel toe-caps protect your toes from dropped bricks, blocks or rocks. They normally also have a steel insole to protect feet from nails, glass or other objects that penetrate the outer sole.
Thorough Mixing is Essential!
When mixing by hand, it is essential to thoroughly mix the concrete to get consistency throughout the mixture.
Can I Mix Concrete in a Bucket?
Sure you can if you only need a small amount!
- If you need to mix a small amount of concrete, for instance half a bucket, place the stone and sand and finally the cement into the bucket.
- You can use a garden or block layers trowel for mixing. Water is then added slowly and mixed throughout the bucket. Cement should be stiff enough to hold its shape in a pile only slum a small amount.
- Add more water until the concrete is at the required consistency. If the mixture becomes too sloppy, add more cement. If you are filling a hole in the ground e.g. around a post, the mixture can be a bit more sloppy so that it more workable and flows easier.
Mixing Larger Quantities of Concrete
Larger quantities of concrete can be mixed on a flat surface on the ground.
You can measure the proportions of the mix by counting shovels. However I find it easier to use buckets. If you go for a C20 mix, a single mix using buckets ( which totals 7 buckets of material) is enough to produce a wheelbarrow of concrete.
So remember for a C20 mix you need:
- 1 bucket of cement
- 2 buckets of sand
- 4 buckets of stone
Note: Ideally check your application to determine the specific proportions recommended for the mix.
Should Concrete be Sloppy or Stiff?
Ideally concrete should be able to stand up in a pile on a shovel and not slump. The link in the reference section of this guide explains the details of slump tests.
Step 1: Spread a Plastic Sheet on the Ground
If you're using polythene sheet, spread it on the ground and weigh it down with blocks/bricks or whatever at the edges in windy weather
Step 2: Measure Out the Materials
You can count shovels or alternatively measure into buckets. Buckets are likely to be more accurate because a shovel of material can vary somewhat in size. A separate dry bucket is advisable for cement, otherwise it'll stick to the sides if the sand or stone measured beforehand left it damp.
Step 3: Place the Stone and Sand on the Sheet
Place the stone onto the ground followed by the sand. Alternatively you may have gravel which is a composite mix of large and small stone and sand. If there isn't much sand in the gravel, you can add some more
Step 4: Place the Cement on Top of the Sand and Stone
Place the cement evenly onto the top of the pile. Crumble up any lumps.
Step 5: Shovel to One Side From the Edge of the Pile and Repeat Three Times
If you have someone to help you mix, it will be easier. Start at the edge of the pile with the other person facing you. The aim is for both people to keep shovelling the pile to one side to create a new pile adjacent to the old pile. Repeat this three times so that's four mixes in total.
Step 6: Make a Deep Crater and Add Water
Now it's time to add the water. Make a crater in the top of the pile about half its diameter so that it looks like a volcano. Again, it's important that the pile doesn't have slopes that are too steep so when you add the water it breaks through the crater and runs down the slope! Add half the water, the amount depends on the amount of dry mix you have created.
Step 7: Fold the Mix in From the Sides
Now with the shovel, go around the edges of the crater and keep sliding the mix into the center. Then use a chopping motion with the edge of the shovel to mix the water with the dry mixture. Continue to shovel the dry mixture from the edges of the pile towards the center. Eventually the mixture will become easier to control as the water becomes more distributed.
Step 8: Continue to Fold Inwards and "Chop" the Pile to Distribute Water Through the Mix
Keep sliding the shovel under the mixture and turn it over bit by bit and use a chopping motion with the edge of the shovel to thoroughly mix and work water into any dry spots.
- Use timber boards placed at strategic points to act as ramps and bridges so that you can get your wheelbarrow over uneven terrain and ground at different levels
- Don't try to push a loaded wheelbarrow up a step, it's easier to pull it
- Spread concrete with shovels and a rake after you tip it out of the barrow. You can also make up a makeshift rake using a long length of timber with a board nailed to the end
- If you use a cement mixer, obviously you can empty the concrete directly at the point where you need it, rather than transferring to a wheelbarrow
- When laying concrete floor sections adjacent to each other, feather the edge of the new concrete with a sweeping brush so that it blends with the previously laid section
Laying a Concrete Slab
- If you're laying a concrete slab, tip the mix from the barrow within the formwork (the boards which bound the slab) and furthest from the front. Roughly scrape out the barrow and use a rake to spread the concrete, making sure its pushed into all corners. Use the back of the rake with the handle vertical to compact and pack the concrete, especially around the edges of the formwork.
- Start a new mix
- Continue to build up the level of concrete until it's about 1/2" above the formwork boards.
- If you work fast and alone, you should be able to lay about 3 barrow loads of concrete before a slab needs to be screeded (roughly levelled flush with the forms with a timber board)
Curing of Concrete
During curing or hardening of concrete, a process called hydration occurs where water chemically bonds to cement. So some of the water you added actually never dries out. It is locked to the cement in a bond forever!
Protecting Concrete in Cold Weather (or Dry Weather)
The best time to make concrete is when the weather is mild. Freezing weather conditions can weaken concrete and hot dry weather can cause water to evaporate too quickly so that there is insufficient water for it to cure properly, resulting in cracking.
Until concrete cures, it should be protected from the weather and never allowed to freeze for the first 24 hours. Minimum curing temperature should be 40 F (4C). In freezing weather conditions, water in concrete expands as it freezes. As ice crystals grow, they push the concrete outwards, breaking bonds between cement, stone and sand. Then when they melt, they leave millions of micro-cavities, so the concrete ends up porous like a sponge, potentially weakening it.
You can cover concrete slabs after laying with blankets/polystyrene/bubble wrap or whatever to help prevent it freezing. If frost is due to set in at night, lay your concrete early in the day so that it firms up, before covering with insulating material (otherwise it'll get marked by the covering).
In hot, dry weather, wait for a few hours until the concrete firms up. Then cover it with polythene to prevent moisture loss and cracking.
How to Make Concrete Stronger
Concrete is only strong in compression, not tension. This means that it'll withstand being squeezed but not bent. So for instance a concrete pillar in a building can withstand tons of weight pushing down on it, but a concrete beam spanning an opening (e.g. a large doorway in a building) would snap under moderate load. To strengthen it, steel bars called reinforcing bar or rebar is inserted when the concrete is wet. Because steel is strong under tension, the resulting composite material becomes strong both under compression and tension.
You can add rebar rods or grid to concrete when laying floor, pads or anywhere you think that it'll be subject to heavy loads and in danger of cracking. It's also a great way of getting rid of any scrap iron you've accumulated.
Does Cement Have a "Best Before Date" and How Do I Store It?
Use cement within 3 months of the date of manufacture on the bag. Store it off the ground to prevent moisture soaking into the bags and making it lumpy. If you can, buy it in plastic rather than paper bags. These are easier to seal with tape if you don't use the whole bag.
How to Mix Concrete With a Cement Mixer
If you decide to use a cement mixer, checkout my other guide, "Easy Steps to Mixing Concrete With a Cement Mixer"
Concrete Technology. The Constructor. Retrieved January 15, 2022, from https://theconstructor.org/concrete
Concrete slump test for workability -procedure and results. The Constructor. (2021, May 16). Retrieved January 15, 2022, from https://theconstructor.org/concrete/concrete-slump-test/1558
Irish Cement - mixing by hand. (n.d.). Retrieved August 9, 2022, from https://www.irishcement.ie/howto/wp-content/uploads/2019/03/Irish-Cement-Mixing-By-Hand.pdf
Concrete properties, testing & standards. The Irish Concrete Society. (2018, December 18). Retrieved August 20, 2022, from https://concrete.ie/about-concrete/concrete-properties-testing-standards/
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
Questions & Answers
Question: What volume of concrete would your 7 bucket mix make?
Answer: About a wheelbarrow. Buckets are 3 imperial gallons or 3 x 4.54 liters. From a quick Google search, a builder's wheelbarrow is 65 to 85 liters in volume.
Question: What is curing?
Answer: It's a chemical reaction in the concrete during which water bonds with calcium compounds. During the curing process, excess water also evaporates and the concrete becomes stronger.
Question: How long does it take concrete to cure?
Answer: Under normal drying conditions, you can usually walk on concrete after 24 hours. A general rule is that it reaches 70% strength after a week and a month to get near full strength. Concrete will continue to strengthen however over months and years. Its best to avoid putting heavy items on it for a week and don't drag things across it which can leave scrape marks.
© 2012 Eugene Brennan
Jacob Shuma on March 13, 2019:
How do I hand mix concrete for feature beam with normal materials e.g cement, stones and crusher sand?
VCA Mobile Concrete on March 06, 2018:
Great! Thank you for the sharing us this knowledge, How to Mixing Concrete by Hand.
Rick on April 18, 2017:
In Peru, we use three(3) small wheelbarrows (about 20 full shovels per wheelbarrow) of sand/rock mix (called 'ripio') to one 42.5kg sack of Andino Type I cement. I've seen it mixed as light as seven(7) wheelbarrows/sack but, I don't know that I would trust that ratio.