Last time we talked a bit about planning your ABS or PVC drainage system. Here are some more tips on laying out and assembling the system.
When changing direction on the horizontal, try and keep the change of direction even more gradual. A sharp corner on the horizontal is a good way to clog things up.
Plan for cleanouts at the upstream end of every horizontal run. These fittings allow you to remove a cap and get access to the drain with a plumbers snake if you have clogged pipes. Check the code to be sure you have cleanouts in all the necessary locations.
Assemble from the main stack or drain and work upstream.
Always dryfit the parts before gluing. The glue dries very quickly.
You’ll be working in tight spaces at times, so it’s often easier to assemble sections of two or three fittings beforehand, then install them as a unit. When you’re trying to confirm an angle, stick a piece of long pipe in the fitting to get a better idea.
Try not to leave globs of glue or plastic shards on the inside of a pipe. These can trap debris and cause a clog.
You may want to consider using iron pipes where the drain runs alongside living areas. If you’d rather not, be aware that the sound of water in plastic can be noticeable, and you may want to insulate to cut down the noise.