How much stone do I need for the ground?
For pebbles and gravel:
• ±80 kg per m², based on a 5 cm layer.*For grain sizes >32 mm a thicker layer is required.• Consumption per big bag: 1000 kg = 0.625 m³.
• Coverage: ±12.5 m² with a 5 cm layer.
For pine bark:
• ±70 L per m², based on a 5 cm layer.
• Consumption per big bag: 1000 L = ±1 m³ = ±600 kg
• Coverage: ±14 m² with a 5 cm layer.
For volcanic rock, slate and chamotte:
• ±50 kg per m², based on a 5 cm layer.
• Consumption per big bag: 1000 kg = ±1 m³
• Coverage: ±20 m² with a 5 cm layer
How much stone do I need to fill a gabion?
Density of ±1,650 kg per m³.
The calculation is easy to understand with an example: for a gabion measuring 100x50x30 cm, do the following:
1x0.5x0.3 = 0.15 m³
0.15x1,650 = 247.50 kg of stone.
*It is always a good idea to allow 5% extra, as gabions widen slightly when filled and always take a little more stone than the theoretical calculation.
PLEASE NOTE! Before buying, read this information about gravel and pebbles
Grain sizes are sieve sizes, not exact measurements
When we talk about stone of, for example, 60-80 mm, we mean that the stones pass through an 80x80 mm square mesh and do not pass through a 60x60 mm one. A stone 100 mm long and 65 mm wide can easily pass through that 80x80 mesh, because the mesh sorts by the width of the stone as it passes through, not by its total length. That is why it is normal for a percentage of stones to have some dimension above 80 mm or below 60 mm.
Machines do not sort 100% accurately
In addition, no industrial sorting process is perfect: there is always a small percentage of stone which, due to speed, irregular shape or pieces overlapping on the belt, does not pass correctly through the corresponding mesh and slips into the grade, so stones larger than stated may occasionally appear. This is normal for this type of product and is not considered a defect.
Breakage of pebbles
In pebbles over 60 mm, up to 10% of the stones may break during sorting, washing, loading and unloading. We currently have no machinery that completely prevents this breakage. The product photos show only real pieces: broken pieces have not been removed.
Dust and sand in the product
This product is not washed, so it contains dust, sand and even traces of other materials from processing and transport. This is no problem for its use: the stone washes itself over time, or you can rinse it with water before use if you prefer.
Colour can vary considerably between batches
This is natural stone, and the colour changes from one batch to another, sometimes noticeably. This is especially important for multi-toned stones such as Blanco Rosa: some batches come out very white and others very pink, within the same product. If the exact shade is very important for your project, we recommend not buying this type of product online, as we cannot guarantee that the batch you receive will match the photo or a previous purchase.
Returns
Please bear in mind that returns, especially of 1,000 kg big bags, are usually complicated and expensive because of the weight and volume of the material. If the return is not due to an error on our part, the costs and arrangement of the return transport are borne by the customer.
Give your garden or outdoor project an organic, living, deeply natural look. Natural Volcanic Gravel (pozzolan) is a landscaping favourite thanks to its light weight, its ability to retain soil moisture and its excellent performance against temperature swings.
It protects roots, reduces watering frequency and creates a highly porous layer that prevents evaporation and smothers weeds.
Natural stone is unique and changeable; it is not a ceramic or industrial product made in series. For Natural Volcanic Gravel in particular, please bear the following in mind before ordering:
Lively, highly variable tone: the colour of this stone changes radically with daylight and, above all, with moisture. Dry, it shows matt greyish and brownish tones; wet or under the rain it reveals much darker, deeper shades.
Same quarry, different batches: the Natural and Red versions come from the same quarry veins. Natural Volcanic Gravel may therefore contain inclusions or traces of red/garnet volcanic gravel, as well as noticeable tone variations between extraction batches.
Order your whole project at once: if you will need more material in the future, bear in mind that a new batch will differ in tone from your previous purchase. We recommend ordering 10% extra or covering the full surface in a single order.
Exchange and returns policy: due to the geological nature and inherent colour variability of this stone, exchanges or returns motivated by colour or tone differences are not accepted.
Water savings and moisture retention: its porous structure works like a natural sponge, keeping moisture in the substrate and reducing the need for constant watering.
Thermal insulation for roots: it protects the soil from winter frost and prevents overheating during the summer months.
Low weight, easy handling: being much lighter than other pebbles or granite, transporting and spreading it requires noticeably less effort.
Zero maintenance: once in place, it needs no treatment, painting or special care.
Prepare the ground: clear the surface of organic debris and loose stones.
Lay a weed-control membrane: essential to stop unwanted vegetation and keep the stone from sinking into the soil over time.
Apply the right thickness: spread at least 2 layers of stone for perfect visual coverage and maximum soil protection.
Yield: 1 m³ (1,000 litres) equals approx. 900-1,000 kg.
10-25 mm grain size: recommended layer thickness of 4 cm (approx. 40 litres / 0.04 m³ per m²).
25-50 mm grain size: recommended layer thickness of 8 cm (approx. 80 litres / 0.08 m³ per m²).
💡 Not sure how much you need for your surface, or looking for technical advice? Contact the Vetonek customer service team and we will help you work out the exact litres or bags you need.
💡 Torn between natural and red, or unsure how much you need? Read our complete guide to volcanic stone for the garden.
For gravel and pebbles you need approximately 80 kg per m² with a 5 cm thick layer. A 1,000 kg big bag (0.625 m³) covers about 12.5 m² at that thickness. For slate, volcanic rock or chamotte the amount is lower, around 50 kg per m² (20 m² per 1,000 kg big bag).
For decorative use a layer of about 5 cm is recommended. With grain sizes above 32 mm it is advisable to increase the thickness slightly so that the stone covers the surface well.
Yes, it is recommended to lay a geotextile (weed control) membrane before spreading gravel or pebbles. It prevents the stone from mixing with the soil and reduces weed growth.
The grain size (e.g. 60-80 mm) indicates the sieve size the stone passes through, not an exact measurement. A stone 100 mm long can still pass through an 80 mm mesh if its width allows, and no sorting process is 100% perfect, so it is normal to find some percentage of stone outside the stated range.
Yes. In pebbles over 60 mm, up to 10% of the stones may break during sorting, washing, loading or transport. It is not a defect: the photos show real pieces, with broken ones not removed.
No, the product may contain dust, sand or residues from the extraction and transport process. It does not affect its use: over time (rain, watering) it cleans itself, or you can wash it yourself before laying it.
No. As it is natural stone, the colour can vary from one batch to another, especially in mixed-tone stones. If the exact shade is important for your project, we do not recommend buying without seeing it first, as we cannot guarantee it will match the photo.
The average density is about 1,650 kg per m³. For example, for a 100x50x30 cm gabion (0.15 m³) you will need approximately 247 kg of stone. It is advisable to allow 5% extra, as a little more stone than calculated usually fits when filling.
