Our Old House: Plumbing Page

The Bathrooms: Plumb Crazy

Supply lines, and drain pipes, and vents, oh my...

Adding a second bath and a laundry alcove, as well as rearranging the main bathroom, meant there was lots of plumbing work to be done. I had no idea before Wayne started this job just how much went into getting the plumbing set up for all the fixtures.

Did you know that part of doing the drain plumbing involves going up on the roof? I never noticed pipes sticking out of rooftops before, but now I recognize them from the vents that Wayne installed. They're called vent pipes because they vent sewer gasses, which is also why they are required to terminate above the roof. The vent pipes equalize the pressure in the drain pipes so that the water can flow. Otherwise, it'd be like when you put a finger over the top of a straw and it traps your soda in the straw.

As usual, it all begins with planning. The drain pipes were the hardest to figure out since they are so big and unwieldy, and because of gravity flow. That is, you have to get the angles right so that it all flows naturally with the help of gravity. Here were some of the factors Wayne had to consider, as well as a photo of the finished drain pipes:

Drain pipe elbows only come in 90°, 60°, 45°, and 22.5° angles, and then there are also Y-shapes and T-shapes.
Any horizontal pipes have to have a slope of 2%
Drains need to be connected to vertical vent pipes. It is always best to try to have the minimum amount of roof penetrations possible, which means trying to consolidate your vents.
ABS and PVC pipes are connected using a solvent which sets in a few seconds. You only get one shot at getting it right. Plus, the solvent lubricates the pipe a bit, and you push the pieces further together than when you dry fit them, which can mess up your delicate arrangement. (Side note: We used ABS pipes because of the health and environmental concerns linked to PVC.)

Laying out the supply connections was less complex, but involved soldering. Solder is an alloy (including tin or silver) that has a low melting point. It is used to seal up connections betwen copper pipes like those in the supply pipes we were using. First Wayne cut the straight pipes to length and dry fitted the copper pipes to make sure all the connections lined up properly.

What We Did: Soldering

Cleaned the two surfaces that were to be bonded. Rubbed an emery cloth around the outside of the pipe, making a shiny new surface. The interior can be cleaned with the emery cloth or a wire brush.
Brushed some flux onto the cleaned surfaces. Flux is a mild acid that will ensure a good bond by preventing the formation of copper oxides when the copper is heated.
Fit the pipe connections back together.
Applied heat to the reconnected joints. If there were wooden floor joists nearby, Wayne had to use a flame guard (a piece of fire-resistant cloth) to shield the wood, or he just sprayed water on the wood shortly before applying heat. He tested the heat of the pipe by seeing if the solder would melt on contact with the hot pipe. If not, he continued to heat it. If it was hot enough, he moved the flame slightly away.
He immediately fed solder into the pipe junctions, starting with the side opposite the flame. The solder should melt around the pipe towards you. Wayne moved the solder around the joint to make sure it was completely sealed.
Finally, he waited a few seconds then wiped the joint clean with a damp cloth to give it a nice, finished look.

Here is a picture that shows the types of plumbing pipes Wayne installed in the bathroom. (On the left are the laundry pipes. The grouping in the middle is for the sink. The vent pipe on the right is behind where our toilet now is; it connects with the toilet drain pipes beneath the floor.):