A former owner installed a toilet with no vent. it never caused big
troubles, but i had to pull it some indoor french drain can be
installed. the flange is cracked. basement toilet used mostly for
emergencies....

anyhow want to replace the sewer line, its most terracota pipe with
tree roots.

any suggestions on venting it properly?

there are those indoor vents used for smaller applications, is there a
large version for toilets?

on rare occasions the trap water would disappear.......

theres no conveient vent line available

suggestions appreciated