The turf roots should have established in about 14 days in warmer weather.
You can test this by lifting the turf slightly and the turn cannot be easily lifted – the first mow should be left until the grass blade length is about 60-70mm in length.
Mow along the turf rolls until you are satisfied that the lawn has established and then for subsequent mowings vary the cutting direction to promote evenness.
Make sure your mower blades are sharp to provide a clean even cut. The general rule of thumb for mowing is never to remove any more than a third of the blade length in any single mowing.
The optimum mowing height for Sir Walter is between 25-40mm and should be left at approx. 50mm in shady areas. In winter it is advisable to increase the mowing height another 10-15mm.