London stock brick is the most commonly used type of building brick in London. Its distinctive yellow colour and soft appearance comes from the yellow Kent clay from which the bricks are made. Available in 100, 140, and 215mm Hollow. Dense concrete blocks can be used in virtually any part of the project in normal conditions. Evalast blocks excellent sound insulation and high strength makes them especially applicable to partition and separating walls. They can also be used as infill blocks in beam and block flooring systems.