TR-21 – Projecting Brick Plinth Detail

This construction drawing shows a projecting brick plinth approximately 600 mm high at the base of a rendered masonry cavity wall, coordinated with a trench-fill foundation and insulated ground-bearing floor.

The plinth is formed using facing brickwork with a dense masonry backing unit to create a thicker composite outer leaf. The rendered blockwork above is set back to form the projection. The drawing illustrates the structural support, cavity construction, insulation, cavity tray, DPC, weep vents, floor slab, damp-proof/radon membrane and perimeter insulation.

Supporting notes cover:

• Construction of the composite brick-and-block plinth.
• Supporting and connecting the two masonry thicknesses.
• Stainless-steel masonry connectors or bed-joint reinforcement.
• Foundation support beneath the complete outer leaf.
• Cavity-wall ties and retaining clips.
• Continuity of the clear residual cavity.
• Cavity insulation through the plinth transition.
• Cavity tray, stop ends and weep vents.
• Weathered plinth bricks or proprietary plinth cills.
• Bellcast or drip beads at the base of the render.
• Horizontal DPC above external ground level.
• Ground-bearing floor and trench-fill foundation construction.
• Damp-proof and radon-barrier continuity.

The customer receives one downloadable PDF construction drawing, prepared at a scale of 1:10 and arranged for an A3 sheet.

The plinth dimensions, masonry support, connectors, ties, cavity tray and foundation must be verified for the individual project. Brickwork, render, sealants and associated components should be mutually compatible and installed in accordance with the structural design and manufacturers’ instructions.