This can be done by pre-cutting top plates to size and placing 250mm x 12mm bolts at 1m intervals.

After the walls are filled with wet concrete and trowelled flat, the top plate can be placed on the wall and the bolts pushed into the wet concrete.

If this is not possible the 250mm x 12mm bolts can be placed at 1m intervals in the concrete so they protrude at least 65mm above the concrete.

Top plates can then be fitted to the bolts later, as required.