Tiki Installer cannot proceed

The directory '/var/www/html/db/' is not writeable.
The directory '/var/www/html/dump/' is not writeable.
The directory '/var/www/html/img/wiki/' is not writeable.
The directory '/var/www/html/img/wiki_up/' is not writeable.
The directory '/var/www/html/img/trackers/' is not writeable.
The directory '/var/www/html/modules/cache/' is not writeable.
The directory '/var/www/html/temp/' is not writeable.
The directory '/var/www/html/temp/cache/' is not writeable.
The directory '/var/www/html/templates_c/' is not writeable.
The directory '/var/www/html/templates/' is not writeable.
The directory '/var/www/html/whelp/' is not writeable.