Sharp Sand: What Is It And When Should It Be Used? (Plus FAQs)

What is Sharp Sand?

Sharp sand is a type of sand made from quartz rock. It has larger and sharper grains compared to building sand, which gives it a gritty and coarse texture. By not washing it as thoroughly as other sands, it maintains its angular shape and roughness. It is primarily used in landscaping projects and to make concrete.

It is often red or orange and is also known as coarse sand, grit sand, concrete sand, holm sand, river washed sand, gravel sand, ballast sand, and pit sand. There are no differences in these products, just their names.

What is Sharp Sand Used For?

Sharp sand is a versatile building material and is commonly mixed with cement to make concrete, screeds, renders, and as a base for pavements, slabs, driveways, and artificial grass. It is also used when gardening to create good potting soil, loosen clay soil, improve lawn drainage, and to dress lawns.

It can also be used for blinding and is the type of sand that is found in ballast, which is an aggregate used to create strong, long-lasting concrete.

Can You Use Sharp Sand For Mortar Mix?

While not recommended, it is possible to use sharp sand instead of soft building sand to create mortar for bricklaying. However, the mortar will be difficult to work with and will therefore make your job harder than it needs to be.

Sharp sand creates a much stronger bond than that required for bricklaying. This makes it inflexible and may lead to excessive cracks over time as the building naturally moves. Soft sand would also give you a smoother finish when pointing.

There is however an exception to this rule. Sharp sand is used to create hydraulic lime mortar, which is a type of mortar that was used before the invention of cement. Today it is used to restore historic buildings.

In some instances, where a less flexible mortar is required, you may want to mix both types of sand together to create a blend that gives you the best of both materials.

How Much Sharp Sand Do I Need For Artificial Grass?

You will need a 10-15mm deep layer of sharp sand underneath your artificial grass to bind it to the sub-base, which is usually MOT Type 1 or limestone. This works out at approximately 20kg per m2 for a 10mm base or 30kg per m2 for a 15mm base. Using a 15mm base, instead of a 10mm base, will increase the amount you need by 50%.

The table above shows how much sand you will need for your artificial grass based on the size of your preferred layer. To work out the m2 measurement of your space, multiply the width by the height.

While sharp sand can be used to bind the sub-base for artificial grass, it may eventually wash away. For this reason, grano dust may be a better-suited material because it is heavier and provides a stronger bind, which will hold firmer for longer.

How Much Does Sharp Sand Cost?

Sharp sand costs £4.34 per 25kg bag and £65.97 per 800kg bulk bag. This works out at £0.17 per kg and £0.08 per kg, respectively. These costs are based on average retail prices from builders merchants and include VAT. Customers can get a more competitive price if they sign up for a trade account or buy in bulk.

Difference Between Sharp Sand and Horticultural Sand

The difference between sharp sand and horticultural sand is the amount of salt they contain. Sharp sand contains more salt than horticultural sand. This is bad for plants as the salt absorbs water, which dehydrates the roots.

This means the two products are not exactly the same. However, if you are going to use it instead of horticultural grit for gardening purposes, make sure it has a low salt content.

How to Compact Sharp Sand

You can compact sharp sand using a plate compactor, heavy-duty hand roller, hand tamper, or a sledgehammer. Before you start compacting, wet the top of the surface to reduce the amount of dust that will be generated. A little bit of water may also help achieve a firmer compression.

Be careful not to compact too much if it is in contact with non-load bearing walls as they could be moved if too much pressure is applied. External load-bearing walls will not have this issue.

What is Recycled Sharp Sand?

Recycled sharp sand has been created using waste from construction projects. It contains crushed concrete, crushed glass, and reused sand. It is an environmentally friendly alternative to quarried and dredged building materials. 

Using recycled sand reduces the need to disrupt natural deposits and also reduces the amount of sand that goes to waste. It is also cheaper and a good option for those on a budget.

Does Sharp Sand Kill Moss?

Sharp sand can help kill moss by reducing the dampness of the soil. Moss grows on grass with excess moisture and indicates there is a drainage problem. Pricking your lawn with a garden fork and sprinkling grit sand will help improve drainage and create conditions that do not favour moss.

How Many Bags of Sharp Sand in a Bulk Bag?

There are 32 bags in a bulk bag. This assumes that the bulk bag contains 800kg and the smaller bag contains 25kg. In reality, this is likely to vary slightly as bulk bags can contain plus or minus 5% of the advertised amount.

How Many Bags of Cement to a Bulk Bag of Sharp Sand?

When making concrete you will need 8 25kg bags (200kg) of cement for every bulk bag of sharp sand. This is using a 4:1 ratio of sand to cement and assumes that a bulk bag contains 800kg. You would need 250kg or 10 25kg bags of cement per tonne/1,000kg of sand.

How Much Sharp Sand Do I Need For Block Paving?

You will need a 50mm layer of sharp sand between your sub-base and paving slabs. This means you will require 100kg per m2 area that is to be covered.

The above table shows how much sand is needed to create a 50mm layer for a variety of block paving areas.

How Much Does a Cubic Metre of Sharp Sand Weigh?

One m3 weighs approximately 1,750kg or 1.75 tonnes. This figure will vary depending on the moisture content, which will increase if stored outside, and exposed to wet weather.

How Much Does a Bulk Bag of Sharp Sand Cover?

Coverage from a bulk bag will depend on the depth of your base. To cover a 1m2 area at a depth of 50mm you will need 100kg. That means an 800kg bulk bag would cover 8m2.

Note: the table above shows how much a bulk (dumpy) bag of sharp sand would cover based on the layer depth. Coverage numbers are rounded down to ensure you do not underestimate the materials you require.

How Much Does a 25kg Bag of Sharp Sand Cover?

Coverage from a 25kg bag will depend on the depth of your base. At a depth of 50mm, which is a common depth for paving projects, a 25kg bag would cover a 0.5m x 0.5m area.

Why is Sharp Sand Used in Concrete?

Sharp sand is used because it creates strong concrete. Its rough particles interlock to generate a strong bond that results in better concrete compared to other building sands. It is often mixed with stones and gravel to make an even stronger aggregate known as ballast.

How Much Sharp Sand for a Shed Base?

You need to add a layer that is at least 25mm deep to the sub-base of a shed. For an 8ft x 6ft shed, this means you will need 223kg, which equates to nine 25kg bags.

The table below shows how much sharp sand you will need depending on the size of your shed base.

Related Building Materials

Kiln Dried Sand
Railway Ballast