Looking at properties near Chesapeake Bay as a vacation place and ultimately our retirement home.
We were in one this weekend which currently has a septic system. The terms of sale require that the buyer connect to the new municipal sewer. The municipal sewer line is already run into one corner of the unimproved, full basement and capped (4″ PVC).
The new homeowner will be required to connect to the municipal sewer and then pay a County crew to come and pump out the existing tank, crush the tank in place and fill the resulting hole – charge $ 750, very reasonable. This assures the County that the old system will never be used again.
The house is a small “raised ranch” with very simple, and very accessible plumbing. One bath, the kitchen sink and a washing machine hook-up.
The only problem is that the main drain line to the septic system exits from the rear of the house and the municipal sewer exits from the front of the house.
Therefore, the general plan of the drains needs to be reversed to exit out of the front of the house.
All of the drains are clearly visible from the basement and probably does not involve more than 50′ or 75′ of piping in total including replacing the main vent out of the roof.
I have always held that “the bigger the drain, the better”, but I am not really sure that this is true in all cases. For instance, if the building code says I must have a 1-1/2″ drain line from a kitchen sink – is there any harm or downside to installing a 2″ line? My theory goes that by having a bigger drain line, potential clogs would tend to happen very close to the fixture, most likely in the trap arm and be much easier to deal with there rather than somewhere farther down stream.
My concerns revolve mostly around decreasing the length of the “flush cycle” in a larger pipe. My intuition says that for a given volume of water the pipe will be active for a shorter period of time but at a higher velocity.
I understand there are potential problems with physical size like a 4″ pipe will not fit into a 2×4 stud wall and that the larger pipes = more $ for pipe and fittings. I would be looking for a trouble free installation in my golden years (when they get here!).
Thanks in advance for any thoughts / experiences / insights!
Jim
Never underestimate the value of a sharp pencil or good light.
Replies
You know those adjustable spray nozzles for garden hoses. When you're trying to wash those pebbles and rocks off the driveway and ther's a bit larger rock, does it move best with a tighter spray or stream, or does it move best with a wide angle spray?
Bigger drains are like the wider spray.
Drains have to be large enough to handle all the flow that might be sent down them, but small enough to concentrate the flow so as to handle the larger, ahem, "rocks" that might be deposited.
SamT
I don't thnik it is size that makes a trouble free system as much as how it is layed out and the fittings. I've always had trouble where the fittings were bad choices or fittings were to close to eachother.
Using PVC is such a big improvement over other materials. Just using it will be a big improvement. My last house had a few small leaks that were caused by not using enough glue. That was about it. It was ABS and cast iron under the slab.