What is ‘Wall Plate Overhang’?

Wall Plate Overhang is a common construction defect observed at the frame stage and is often highlighted in a ‘Directions to Fix Notice’ issued by the main RBS or RBI.

At the concrete slab pour stage, temporary bracing and boxing is put in place to create the initial footprint & perimeter of the built-site. With a brick veneer build, this will affect the timber framing which is erected at the top-of-slab perimeter, and then brickwork which is laid on the edge-of-slab rebate.

Once the slab cures, the bracing and boxing are removed. The wall construction then needs to mirror the concrete slab. Framing Carpenters & Bricklayers will often be far more accurate when constructed straight and plumb walls. As a result, the timber frame and brick skin, often do not match the concrete slab, thus resulting in wall plate overhang if these items protrude over the slab edge.

The NCC 2019, and the Guide to Standards & Tolerances 2015, documents the thresholds of the overhang;

* timber frame max of 10mm

* brick wall max of 15mm

The method of rectification is often detailed in the site engineering plans. The greater the overhang, the more structural support required. This takes the form of;

·         Minor overhang:              Non-shrink grout is laminated to the slab edge

·         Moderate overhang:      A timber plate is often chem-set bolted to the slab edge

·         Major Overhang:              A steel plate is often chem-set bolted to the slab edge

If you are building keep an eye out for this easy-to-spot defect!