No idea but if I couldn't upload the revamped site in one go I would build the update in phases that could stand indexing in their own right.

That is classic static html site build, edited and tested off line. Is there anything about the software that you are using that affects the approach?

Actually I generally only take a few hours to update my site however I have considered doing some extra testing with the new version I've been working on just to make sure when it goes live it'll work smoothly for visitors. It's database driven and I avoid static like shark filled pools with overhanging giant hair dryers.

- John

safe from what?
indexing the content?
robots.txt will successfully exclude content from being crawled by well-behaved bots indefinitely.
in some cases you may be better off putting the content on a subdomain or in a subdirectory and hiding it behind basic authentication, so crawler requests get a 401 Unauthorized response.

a good idea can be doing those changes in a separate folder and when it is done, take all the files on root. you dont even have to tell anyone not to crawl since you will not be having any linked reference to that folder, or for your safety, you cna put that folder in robot file and when the changes are done, you cna take the all updated file out of it.

I kept spiders out of my site for six days without major issues apparently. :)

- John