Abstract: A masonry block (1) comprising outer walls (2), at least one abutment wall (3) and at least one vertical cavity, at least one first channel in the upper surfaces of the abutment walls and/or in the lower surfaces of the abutment walls, wherein the abutment walls include vertical edge surfaces (7) for engagement with abutting blocks, a vertical land (8) disposed between the vertical edge surfaces wherein said land has a keyway (9) for receiving a key to lock adjacent blocks in position and a pair of vertical channels (10) disposed between the vertical land and the edge surfaces, the arrangement and construction being such that when blocks are laid one upon another the channels and the said at least one cavity of the blocks can be aligned to provide an internal network of horizontal and vertical grouting passages which can be filled with settable material to seal joints between the blocks and to provide load bearing support between respective layers of blocks.

Abstract: An improved key for a dry wall block system is provided with a plurality of longitudinal flanges and a common web. The keys are adapted to engage with slots in the ends of building blocks to align and join the blocks and provide improved stability during the erection process.