By Margaret Heidenry | Jun 17, 2019
Planning to remodel your bathroom into the oasis of your dreams? Then you’d better get a handle on your plumbing. Even if you don’t see the pipes connected to your sink or shower, understanding how they work is essential if you want your bathroom renovation to turn out all right (and within budget).
That’s why, in the latest installment of our “Dream Bathroom Remodeling Guide,” we break down everything you need to know about plumbing into bite-size pieces. Read on for some surprises!
In the past, most bathroom plumbing pipes were made of cast iron or galvanized metal. However, these pipes won’t work with many of the newfangled, water-saving setups like, say, low-flow toilets. Low-flow toilets will save about 17,000 gallons of water yearly. (Note: Flushing a standard toilet uses about 38% of an average household’s water.) The catch is, they require PVC (polyvinyl chloride) or PEX (cross-linked polyethylene) pipes. But updating to these kinds of pipes is both easy and affordable.
“These new types of pipes are flexible—and thus very simple and inexpensive to install,” says Cassidy Melhorn, a pipe design engineer and founder of Knoxville’s Volhomes.
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You also need to figure out if you prefer hidden or exposed plumbing when you’re looking to buy your sink, tub, or toilet.
“Exposed plumbing is the more traditional look, while hidden plumbing is much more minimalist and cleaner-looking,” says Ryan Holden, director of Progressive Heating & Air, an HVAC and plumbing company in San Diego.
If you have a lot of visible plumbing, you might want to use copper pipes instead of PVC or PEX, because copper is more appealing aesthetically. Just keep in mind that it’s more expensive and difficult to work with, since sawing and fitting these pipes into place will take more work than cutting soft, flexible PEX/PVC.
Regardless of the material, consider insulating these pipes, which can help reduce the amount of heat lost as your water travels from the heater to the faucet.
The existing water and drain lines in your bathroom usually dictate the location of fixtures in your renovation. You can move pipes and drains—although it’ll cost you—but some relocations might be impossible.
For example, you may be dreaming about a large tub right next to the bathroom window.
“But if the piping won’t allow for this configuration, then you will need to rethink the entire layout,” says Holden. This all comes down to drain line access. While it’s usually feasible to relocate a large fixture, the supporting joists beneath the bathroom floor usually can’t be cut in order to install new drains.
Bottom line: Before you buy any fixture that connects to a pipe, sit down with your contractor (or a plumber) and have a conversation about what’s feasible.
The good news is that there’s something called the National Pipe Thread, which is a U.S. standard size for a fitting that connects rigid pipes such as shower heads to the shower arm pipe in your shower. That means if you’re replacing a shower head, most fixtures out there will fit the existing pipe.
The bad news? That new shower head may not work with your existing water pressure. New shower heads are now required to restrict water flow and deliver less than 2.5 gallons per minute. So if you have low water pressure and add a new water-saving shower head, you may be soaping up under a trickle. To avoid this travesty, have your home’s water pressure checked before you buy your accessories.
“Each home will have a different water pressure, but the average is usually around 45 to 80 pounds per square inch,” says Holden. “It’s the little things like this that people often overlook, and end up buying all their accessories only to find they won’t work with existing plumbing.”
Also keep in mind that there are things you can do to adjust your water pressure. If your water pressure is too low, it’s often due to clogged pipes you can unclog—or if not, you can also buy a water pressure booster. Or if your pressure is too high, you can install a pressure-reducing valve.
A remodel may also call for a water heater replacement—heaters generally last about 10 years—or even an upgrade to a tankless water heater. Also called “demand-type water heaters,” these devices are about the size of a small suitcase and deliver endless warm water only when you need it. Conventional water heaters always have a tank of hot water whether you need it or not, which drives up energy costs. Just note that on-demand heaters cost up to three times more than conventional heaters to buy and install. That works out to about $800 to $3,000 for the unit, and installation can add an additional $1,000 to $3,000.
Renovating is a good time to think about heating, as your walls and floors will often need to be opened anyway.
“Consider installing underfloor heating,” says Holden. Known as radiant heat, this method uses hot water to carry heat through a network of tubing beneath the floor.
“You may wish to have a hydronic heated towel rack installed, too,” he adds.
One last no-brainer for you rookie DIYers out there: Whether you’re swapping out your sink, shower, toilet, or some other water-spouting device, you have to shut off your water first—or else!
You can generally just shut off the water at the fixtures you are swapping out. Sink valves are typically under it, and the toilet valve is generally where the plumbing meets the wall. Some bath and showers have an access panel on the reverse side of the wall, which may house shut-off valves. There’s also a main shut-off inside the house, usually in the basement.