Screeding is the technique of levelling the bedding sand before laying the pathway materials. Find out how it's done.

Screeding is the technique of levelling the bedding sand before laying the pathway materials. This removes any dips and bumps in the sand that would otherwise give the finished path an uneven surface.

A level finish can be achieved by using one of two simple methods: the raised rail or the bedded rail method.


Raised rails

For the raised rail method, drag the screed board over the rails to level and pack the sand.

1. Place timber edges or rails at the finished string line height and peg or nail them in position.

2. Select a straight piece of timber (usually 100 x 50mm), long enough to cover the width of the area to be screeded. Cut a notch from each end, 8–10 mm smaller than the thickness of the paving material to be laid. This allows for later compaction of the sand down to the finished height.

3. Drag the screed board over the top of the rails so that the sand is dragged back by it. Ensure the bedding sand is packed firmly. To make screeding easier, use a steel float to help push back, or remove to one side, the build up of sand that occurs behind the screed rail.

Bedded rails

For narrow paths, use only one bedded screed rail and a spirit level to act as the screen board.

1. This is probably the easier method as there is less preparation and fewer materials are required. Use screed rails made from timber, aluminium or PVC conduit, or water pipe, and bed the rails into the sand (for narrow paths, only one rail is necessary). Make sure that the rails are below the finished string height by the same thickness as that of the pavers, less 8–10 mm for later compaction. To check this, place one of your selected pavers on the screed rail and check its height against the height to the string line.

2. Using a straight piece of timber or a spirit level as the screed board, steadily drag it along the rails, screeding off and packing the sand to create a firm, level laying surface.

3. Remove the rails and fill the holes with sand before you begin laying the path.

Source: Planning & Building Paths, Murdoch Books