Confused about file permissions

I”ve got a client that is insisting on self-hosting their WP sites and I’m not sure how to instruct their server admin in how to configure the machine. The problem is that any files I upload are owned by me/me and any files created by php are owned by apache/apache.

We have a group, wp, that both me and apache are members of.

How does one set up a server so that all new files are always owned by user/wp rather than user/user?

Once that’s happening I should be able to site the permissions so any member of the wp group can read and write those files.

Thanks,
Colin