How many visits is acceptable from a landlord???

He emailed and visited me on Monday to check the progress of the skip... he emailed me again this afternoon - and he's coming again tomorrow afternoon, again under the guise of checking progress on the skip.

At this point, these "checks" feel like more of an inconvenience than they are a help to me because it means that I'm not going to be able to focus on what he wants me to do and I've got to stop and keep an eye out on him visiting because he won't ring the doorbell like a normal person.