How to Install a Multihead Shower System

Builders sometimes feel torn when homeowners request upgrades or customizations to their new homes. The builder wants to keep the customer happy, but if anything goes wrong, it can lead to headaches and costly overruns, especially around installation of special appliances or new technologies. Fortunately, one popular upgrade–a multihead shower system–can be quick and painless.

To help keep the plumbing trade contractor on task, the builder should understand the basics of advanced shower-system installation. This will help ensure that the showering system meets the needs of both the homeowner and the construction schedule.

Multihead shower systems can range from relatively simple "shower towers," which are as easy to install as conventional shower heads, to fully enclosed hydrotherapy spas, complete with foot basins, recirculation pumps and water flow of as much as 80 gallons per minute.

By following these simple guidelines, you can hold bathroom-upgrade nightmares at bay:

• Framing considerations. While most floor-joist framing will be adequate to support a multihead or spa shower system, it's critical that the builder review the manufacturer's installation guide and design plans before framing begins. Special attention should be given during rough-in to make sure that once the unit is installed, it will have a watertight fit. There also must be adequate access to the pump, shower control and drain areas for installation and maintenance.
• Hot-water capacity. While temperature regulators are built into some high-end shower units, it's sometimes advisable to install a supplemental or tankless water heater for multihead units installed in standard shower enclosures.
• Water flow. Depending on the system, water pressure may become an issue. Spa and massage units that aren't for cleansing usually have a storage tank or reservoir and recirculate the water with internal pumps. Simple multihead systems that draw directly from the home's water source should be low-flow, and pipe sizing should be designed for maximum flow. (Check with your plumbing trade contractor or someone who has a "certified in plumbing engineering" designation.)
• Moisture control. As with any bathroom fixture or feature, containing and controlling moisture is key. Be sure to use water-resistant drywall, or "greenboard" as it's often called. Concrete backer board has a solid concrete core and is reinforced with fiberglass mesh; it provides a solid underlayment for wet areas such as whirlpools, shower walls and bathtub surrounds.


Andrew Hunt is a Pittsburgh-based freelance writer. Formerly of BuildIQ, he specializes in construction-related topics.