What are breeze blocks?

Are breeze blocks the same as concrete blocks?

Posted on: February 21st 2024    •    Posted in: Concrete Blocks

In the UK, the term breeze block was often used as a generic term for a lighter weight concrete block, but nowadays it is quite an outdated phrase. Let’s take a look at some of the terminology that’s used for describing and categorising concrete blocks.

What are breeze blocks?

Breeze blocks (CCP’s equivalent is our Modulite block) is a term for blocks made of concrete using coal cinders or lighter weight natural aggregates, whereas a dense concrete block is made from stone aggregates, sand and cement. With breeze blocks, instead of using sand and aggregates, most of the filler material has been ash, and in particular, coal cinder or more recently lighter weight natural aggregates.

Breeze blocks (Modulite) should not be confused with aerated blocks which are much lighter in weight than a concrete or breeze block and are not an aggregate type product.

Where are (Modulite) breeze blocks used?

These blocks are lighter blocks than solid dense blocks and are mostly used indoors as partition walls and external wall inner and outer skins. They are suitable for load-bearing walls of 3.6N 7.3N and 10.4N.

Are (Modulite) breeze blocks as strong as concrete blocks?

Modulite blocks are strong enough for most general uses for buildings up to 3 storeys but much higher strengths are available in dense concrete blocks if required.

What’s a better way to describe and categorise concrete blocks?

Nowadays, the construction industry refers to blocks used in the UK as concrete blocks or Concrete Masonry Units (CMUs). Concrete Masonry Units can be broadly broken down into three types – solid, hollow and cellular blocks.

Solid blocks

These are blocks with no voids in them. These blocks are used in the majority of construction projects and are load-bearing, high quality and robust. They can be used both above and below the DPC. At CCP we further categorise our blocks by the density and their compressive strength.

Solid Dense

Solid dense blocks have a dry density in the range of 1850-2100 and are available in 4 compressive strengths 7.3, 10.4, 17.5 and 22.5 N/mm2 and are manufactured with a close textured finish suitable for painting.

Solid Medium Dense Lightweight Blocks (Modulite)

Modulite blocks are lighter than solid dense blocks and offer a good compromise between strength and weight. These tend to be used where rendering or plastering is to be applied and are available in both standard and paint-grade finish. Their dry density ranges from 1350-1600 and are available in compressive strengths of 3.5, 7.3, and 10.4 N/mm2.

Ultra Lightweight Blocks (Lay-Lite)

Concrete blocks are heavy and our ultra lightweight Lay-Lite blocks are designed to be easier to handle and to reduce the need for heavy lifting. The Lay-Lite range has a dry density of 1020 – 1180 and are available in 2 compressive strengths of 4.2 and 7.3N/mm2 and have the best thermal performance of all aggregate blocks.

Hollow Blocks

A hollow block contains one or more voids which pass through the block from top to bottom. The hollow design of these blocks makes them lighter weight and easier to handle, whilst still providing excellent structural support.

Cellular Blocks

A cellular block contains one or more formed voids that do not fully go through the block. Cellular blocks often make construction easier as they allow for a full bed of mortar when laying the blocks. The cellular design of these blocks makes them lighter weight and easier to handle, whilst still providing excellent structural support.

Other types of bricks and blocks manufactured by CCP

Coursing Bricks

Coursing bricks are smaller in size and are typically used for infilling small areas and coursing up rather than having to cut down larger blocks on site. They can be used both above and below the damp proof course level (DPC).

Foundation blocks

Foundation blocks are designed specifically for use below ground and act as a base to support solid, cavity walls and timber construction as well as for supporting beam and block flooring. Foundation blocks can also be used above the ground in retaining wall situations.

Concrete Commons

Concrete common bricks are used to adjust the height of the course in dense blockwork, and can be used above and below the DPC. They are also used in higher strength walls.

What is Compressive strength?

Concrete blocks are categorised into their compressive strength and CCP manufacture blocks which range from 3.5N/mm2 to 22.5 N/mm2.

A figure of 7.3 N/mm2 means the block can withstand a load of up to 7.3 N/mm2 before it would crack. The higher the number, the higher the load the block can support.


The density of a block is influenced by many factors, including the mix design, the water-cement ratio, the characteristics of the aggregates used, and the mixing and manufacturing process, to name just a few. By optimising these factors, we are able to produce concrete masonry units with the correct density required to meet various construction applications.

CCP’s solid dense concrete blocks typically have a density in the range of 1800 -2100kg/m3

Our medium dense blocks (Modulite) have a density in the range of 1350-1600 kg/m3

Our Lay-Lite range typically has a density of 1020-1180kg/m3

All of our blocks are manufactured to the BS EN 771 standard and carry further accreditation and compliance.

Our blocks utilise our Greenbloc technology which results in the embodied carbon being up to 50% lower than a standard OPC (Ordinary Portland Cement).

Same performance, same cost, lower carbon footprint

Find out more about Greenbloc and how we are helping the construction industry lower its carbon footprint.