They used lead - The Latin name for lead is 'plumbum' hence the name plumber.
lead
Plumbing gets its name from the Latin plumbum, the word for lead.Lead was used for centuries in plumbing as it was soft enough to be easily worked. However, it is a toxin and it was found that some traces of lead were getting into the water passing through the pipes - and was accumulating in people's bodies.
Less conductive I would say.
A room with pipes is a good place to go, especially if you have no basement as the pipes help reinforce the walls, making them less likely to collapse.
PVC pipes are less expensive and easier to repair. Metal pipes are more expensive and more difficult to repair.
There was a loss of good farmland from erosion of the top soil. Also, to fuel the many fires in dwellings and other places, deforestation had a big impact on the Romans. Although this has less to do with the environment their pipes were made of lead which over many years slowly poisoned the people of Rome.
Lead pipes is probably what you are looking for. Iron was used for weapons, armor, and farming tools.
Rigid pipes are more likely to burst since they are more brittle and cannot travel as far when subject to strain.
"Not that I loved Caesar less, but that I loved Rome more."
Many years ago, plumbers used the plumbers candle to join pipes together. Wax from the burning candle would be dripped onto a "wiping cloth" to form a protective coating on the cloth. Molten lead would then be poured onto the cloth and wiped onto the joint of the pipes to seal the joint. The candle wax prevented the lead from sticking to the cloth. This process of joining pipes together was called "lead wiping." It is likely that plumbers needed a candle that would give off a lot of light while they worked in dark confined spaces. They may have asked candlemakers to create a candle that provided more light than a normal taper candle. So, another theory for the origin of the plumbers candle is that the plumbers candle was made specifically to provide light for plumbers as they worked. In the days before paraffin wax, tallow (animal fat or oil) was used to make candles. Plumbers candles used to be made from spermaceti, the oil from the head of the sperm whale. Spermaceti candles were renowned as the brightest burning candles of their times. The plumbers candle was made a bit thicker with a larger wick, which made it burn even brighter. Due to overhunting, the sperm whale become an endangered species, and use of the spermaceti became illegal. Paraffin wax quickly became a replacement for spermaceti and burns almost as brightly. ALSO: Plumbers' candles contain more stearic acid, which means they burn longer than cheap ones which contain less.
Less than 1 mile, you can reach city of Rome.
I charge no less then $18,000 for a 4" pipe and more for larger sizes. -- Depending on your location, the industry average could be much less than that. With any luck, you can get competitive bids from a number of plumbers. You can contact a local remodeling contractor who will suggest a figure if the plumbers will not.