In the process of installing downstairs wc. Uncovered original clay soil pipe 5" OD about 30" down. Need to cut section out and fit tee with flexseal adaptors, would i have to use a 45 degree tee or would a 90 be adequate? could there be blockage issues? from there i would work my way up via a rest bend to floor level. Building control have told me i would need rodding point. Above ground would a 92.5 branch be suitable for access ie. the waste from the wc coming into the side and the top being accessible for rodding. Any thoughts would be appreciated before i order stuff!