What exactly is 'Dubbing Out'?
Preparing the Surface
'Dubbing out' creates an even surface for the plaster/render to be subsequently applied in even coats - haired base coat or lime hemp plaster can be used for dubbing out.
Dub-out the walls with the haired base-coat plaster (in coats not greater than 9mm) where necessary to create an even surface for the first or scratch coat (so that each subsequent coat of lime plaster can then be applied at the same thickness), this should be left to harden before applying the first coat. If there are significant voids, a lime hemp plaster will allow for thicker coats than 9mm.
The application of lime plaster is more involved than using conventional plaster. It is highly recommended to use a plasterer experienced in the use of lime plasters or at the very least you should get some practical experience e.g. on a course, as it is not possible to cover every point in detail here.
Disclaimer - no responsibility can be accepted for any errors or omissions or any loss or damage as a result of using the information provided in these guidelines.