Blockwork

Breeze blocks contain a high percentage of furnace clinker. They are normally used in the internal skin of houses or for internal blockwork. They are very absorbent and have an open textured appearance.
Breeze blocks are not suitable for exterior use. They are normally plastered but can be decorated direct if the coarse texture is acceptable.

Concrete bricks/blocks (including precast concrete blocks) are highly alkaline, therefore painting with solvent-based paints is not advisable unless the brick is completely dry in depth. Concrete blocks are normally used in foundation work or as a backing for render or cladding materials in modern low cost industrial units.

Lignacite building blocks (lightweight insulation blocks) are made of portland cement sawdust and sand. They have excellent insulation properties, nearly three times as much as dense concrete. Lignacite blocks are cheap easy to saw, nail and sometimes have an inner hollow core to provide insulating air spaces which improves sound insulation. Lignacite Blocks are very absorbent, therefore sealing with a thinned coat of emulsion paint is recommended. Lignacite blocks are very alkaline as they contain Portland cement.