Wet Vent Question

[Darktowerjk]

I plan to vent a toilet, shower and lavatory from the lavatory, but I need to go up to ceiling with vent, then elbow out 90 to travel along the top of a wall before elbowing up into the roof.

Is it acceptable to have both vertical and horizontal components of a wet vent? If so do I need to grade like a drain?

Thanks!

Jeff

 

[Smooky]

(905.2) The vent pipe should slope so water, condensation, rain water etc. drains by gravity to the drainage pipe.
¼” per foot for 2” pipe (Table 906.1)