If you have visited our other construction pages you realize that our talents as plumbers are a little weak. That is, although we get the project done as professionally as we can we realize that we are very slow, and like most home owner/plumbers we rely very heavily on lots of couplings to fix our mistakes. This project was started in March of 2000 as part of the hallway demolition and completion of the master bathroom.

This plumbing project has several challenges, they are:

  • Second floor plumbing must enter the crawl space by crossing the joist before dropping down a 2 X 6 wall.
  • New main floor bath plumbing must also cross the joist and NOT drop below them.
  • When the previous owner changed septic systems he eliminated the vent. This results in gurgling drains and poor performance.
  • The waste lines from these bathrooms must enter the basement without removing anymore foundation material.
  • The vent lines must be routed through the attic knee wall area and then out the upper slope of the roof (the lower slope is too steep to accommodate a standard flashing.

The image below shows the waste system as it existed after working on the half bath, which was part of the kitchen project. The 3" line dropping through the floor is the half bathroom toilet and just below this a 1-1/2" line comes in from the bar sink and another from the half bath pedestal sink. The 3" line then travels to the West where it picks up the main line leaving the house.

The image above shows this 3" line running West. You will also see the 3" copper line that is the original main floor bathroom plumbing with the toilet to the left. All of this copper plumbing will be removed when the original main floor bathroom is removed some time this fall. The 3" PVC line running to the right (North) can't be changed so all new plumbing must connect to this existing line. This half bath and main bath, as mentioned above, do not have a vent within an appropriate distance.

So step one was to get the second floor bathroom laid out and plumbing moving in the right direction. Luckily the main floor bathroom ceiling was 8'-4", which was a result of using 2 X 8 joist for the second floor instead of matching the 2 X 12's on the 1975 addition. This allowed me to run the 3" lines along the underside of the joist providing proper fall, these will be hidden by dropping the ceiling 6" once all the plumbing has been run.

As you can see in this image, I have run a double 3" line across the joist. The one nearest us in the image is the toilet drain line and the other is a vent line that will run all the way to the basement providing a vent to the half bath. It will also provide direct venting for the main floor bathroom. I tied these together with a Y fitting and then used a couple elbows to offset it into the joist area on it's way to the attic. I was careful to locate these main lines so that the new ceiling joist will not run into them. The 2" line dropping down the wall is from the second floor bathroom. I used a T fitting to run the vent into the attic where it will pick up the main 3" vent line. There is one other 2" line running across the joist, which is from the second floor tub.

The tub line can be seen dropping through the wall in the image above. You can also see the underside of the stairs leading to the second floor. This will be closed up to form a storage close accessible from the bar. Up until a few weeks ago this space was the only access to this new bathroom area.

Finally this image gives you a picture of how the tub line is connected to the tub with a vent line running South to pick up the 3" main vent line and the image below shows all of the connections as they head for the attic vent system.

This portion of the DWV system took me an entire weekend of work. As I have mentioned, we are not necessarily fast, but every attempt was made to make the plumbing neat and of course our desire was that it worked properly. The next weekend was done from the crawl space under the main floor bathroom and under the bar. After some careful planning I began by cutting one of the joist out of the way of the toilet area and installing headers to support this structural change. This also called for cutting the double joist that supported the partition wall between the bar and bathroom.

This isn't a load bearing wall but cutting the bottom half out of a joist does weaken it terribly, so after I installed the PVC I connected across the cut with a 2 X 4 and then supported it with a post to the crawl space floor. The post is supported by pressure treated lumber that rests on undisturbed dirt. I moved the washed river rock around the post base to keep it from shifting.

I also ran a 1-1/2" line from the West wall of the bathroom to the East side to connect the vanity to the drain system. You can see this running to the left of the toilet line bay in the image above. You can also see it in the image below, but there is a real possibility that I will be removing this line. You see I made a mistake that the professional plumber would have thought of. I drilled 2" holes through the joist, making sure I had fall on the pipe as it headed East. What I forgot about was the fact that the 1-7/8" OD PVC would rub against the joist causing squeaks. The minor flexing of the floor joist is enough to produce a rather pronounced noise that is not acceptable. If I had drilled larger holes I may have been able to slip something around the pipe to eliminate the noise, but the very close fit makes this a problem.

Perhaps the most difficult part of this project was developing a system to connect all the DWV runs to a single 3" line. The connections also had to have was fall on all of it and that the runs did not meet anymore elbows or turns than were absolutely necessary. The image above shows this system and is labeled so you can identify each of the connections. Once out of the new crawl space the 3" drain line and 3" vent line need to turn a corner, connect to the half bath, and proceed to the existing drain line. The images below show the finished project.

I was very hesitant to make that last 90 degree turn before the half bath since I know these tend to slow things down and are a potential for plugging. I chose a wide radius Y fitting instead of the normal short turn and also installed a clean-out plug in the event that this turn presents a problem. This completed the PVC and following bracing and strapping the entire thing we are ready to move onto the water lines. We will report this on a separate page.

If you entered our site on this page and do not see a menu bar on the left you're missing a lot of it. Please press here to go to Sandy and Dan's Home Page