Subdirectory Install Problem

When I have a client who wants a new site design but still wants to keep their old site up and running until I’m finished I do a subdirectory install. When finished setting up the new site I follow codex for Using a pre-exisiting subdirectory install. For some reason this time, when I did so, it would bring me to a white page with content but no layout, images, css. I have no idea why. When I put everything back the way it was prior to following codex, the site is there at the subdirectory install location.

http://algiersurgentcare.com/wp/

So what I did was change the site address to http://algiersurgentcare.com, copy the .htaccess file and index.php file into the root directory. Change the line in the index.php file that says: require( dirname(_FILE_ ) – ‘/wp-blog-header.php’ );
to require( dirname(_FILE_ ) – ‘/wp/wp-blog-header.php’ );, update my permalinks.

So after doing the above, absolutely nothing happened. So I contacted the host provider who said I need to change the domain path to point to the wp directory. When I do that I get the white page and I can no longer log into wp admin. I had to place the following 2 lines of code in my theme’s functions.php file to get back to wp-admin:
update_option(‘siteurl’,’http://algiersurgentcare.com/wp’);
update_option(‘home’,’http://algiersurgentcare.com/wp’);
Then remove those 2 lines of code once back in.

So I’m back to square one. The host provider doesn’t have any other suggestions. Does anyone know what I might be doing wrong or anything else I can try?