I am retro fitting a laundry room in a 200 year old house. The existing drain is not vented. It will be close to impossible to install a new vent trough the roof or to tie into the existing vents in the new addition on the house where the kitchen and baths are located. Are there another ways to vent the system? The laundry room is on the first floor and I'm running new pipes in the wall from the full cellar below.