It is highly likely that ~grunt103 has permissions 0700 which would preclude the apache process owner from reading farther down that tree. Add global execute permission to ~grunt103 and any subdirs which don't have it. Assuming that solves the problem you can consider tightening things further by using the apache group instead of global.

I have disabled selinux but this has made no difference.

It's a handy diagnostic change but you should re-enable it again now. Just check the audit log to see if SELinux is preventing access.