Transferring directory site a subdomain

[Providence]

I want to transfer an existing directory site to its own subdomain and free up the index.

Do I do a 301 redirect and leave the domain to redirect to the subdomain for a few weeks or months?

When do I stop the redirect? I will be needing the index page as the landing page of the domain in the future.

[look4edmund]

Why do you want to create a subdomain when you can start a sub-directory. It's more powerful when everything's in the same domain.

[Providence]

I have been reading that thread about folders and subdomains between John and Expertu.

I think its how I will go.

Anyway, its not the issue I want to ask. I want to maintain my PR. Could this be done?