Decoding Drain Design
Plumbing pipes and fittings in modern bathrooms are predominantly made from some type of plastic material along with supply lines made of copper but it was not always so. If your home was made before 1950, you more than likely have cast-iron drainpipes with galvanized steel water supply pipe lines that sometimes even included branch drain lines too.
The only problem with this material was that even though galvanized pipe is extremely strong, its shelf life was only about fifty years due to the fact that the joints frequently rusted and leaked and the build up of minerals in the pipes reduced water flow and occasionally even clogged the channel.
An alternative to galvanized steel pipe is cast iron piping. Though used chiefly for drain lines and vents, many trades people favour it over plastic pipes because it is heavy and strong.
This has the effect of reducing the sound of water running through the pipes, whereas plastic tubing has an inclination of augmenting the rushing water sound. The other proof using cast iron is that it lasts a life time, some cast iron pipes have been know to last over a hundred years.
Copper piping is a little more expensive than plastic pipes and is ideal for water supply lines because it resists rusting and lasts a very long time. Copper lines comes in three different thicknesses M, L, and K. M is used in residential plumbing while L and K has outdoor applications.
You can even get flexible copper tubing to get around those tight spots. Just be sure not to kink the line or you will have to replace it.