FAI Home › Forums › Public Forums › General Plumbing › FAI This topic has 1 reply, 2 voices, and was last updated 18 years, 9 months ago by Retired plbg1. Viewing 1 reply thread Author Posts 14 Jul 2005 at 6:56 pm #277640 MasterPlumbersKeymaster Is it possible to tie in the FAI from the house trap into an existing FAI used for the drains in the house that goes through the roof? 14 Jul 2005 at 10:09 pm #296764 Retired plbg1Participant Jack what is a FAI, let me know and I will try to answer your question. Spell it out. Art retired plbg Author Posts Viewing 1 reply thread You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In