July/August 2013

PEX Pipe Big Factor In Hotel Renovation

Using PEX-a piping makes possible plumbing replacement in a historical building without tearing out walls.

Jayson Drake, Uponor North America

Historical buildings restored to their original look and feel can be awe-inspiring on the outside and exquisite within. But getting to that point while meeting all of the codes and regulations applicable to this special type of project can involve numerous challenges for building designers and installers. Nowhere are these complexities more acute than in the modern mechanical systems that must somehow fit within the confines of structures designed and built long ago to accommodate something far simpler and smaller.

The Mayo Hotel has been a Tulsa, OK landmark since 1925, although it stood empty for 20 years before its restoration.

“There are lots of hoops and hurdles the owner of a historical building must jump through during the renovation process,” said Todd Ringgold of Palmer Mechanical, a Tulsa, OK-based contractor that has made renovations of historical buildings a major part of its business in recent years. High ceilings—“at least as high as the original building, if not higher,” he says—and plaster walls are musts, of course. While the interiors hearken back to an earlier era, all of the amenities must be thoroughly modern and efficient to attract buyers and tenants. Updates typically include larger bath and kitchen facilities equipped with the latest conveniences.

Proper performance of those amenities demands an equally modern infrastructure, none of which can be conspicuous or take up much space to avoid detracting from the authenticity of the restoration. The updated wiring, ductwork, conduit, and piping for the communications, HVAC, electrical, and plumbing systems usually must fit into the available air space between the floors of these buildings, Ringgold said. “Essentially, we must squeeze a lot of piping into a very small chase.”

The Palmer Mechanical portfolio contains five historical-building renovations in Tulsa over the past decade, including the Philtower Building, the former Tulsa City Hall (converted into a hotel) and—perhaps the most notable of all—the landmark, $40 million Mayo Hotel project. All were design-build projects that allowed Palmer to do its own system-design work to match the infrastructure to the radically altered configurations of the buildings after they had been completely gutted.

“In these buildings, the newly enlarged bathrooms and kitchens don’t line up from one floor to the next as neatly as they did in the older structures with their simple tub-sink-toilet layouts,” said Ringgold, who has served as Palmer’s project manager on each of the jobs. “That’s because the new bathrooms usually include large, marble-and-tile showers with whirlpool tubs, marble-topped vanities, and bigger closets.”

While carving out additional space for larger, better-appointed bathrooms, Ringgold and his crews still must leave enough room for equally well-appointed kitchens, living areas, and bedrooms. “The piping, wiring, venting, and so forth have to be completely redone,” he explained.


The design-build process gave Palmer Mechanical another advantage: more decision-making authority over the types of building materials used on the projects. This enabled the company to use a different type of plumbing pipe: crosslinked polyethylene (PEX-a) instead of copper.

PEX-a’s flexibility and ease of use are major labor-saving, stress-reducing improvements over the rigid copper and plastic systems of the past. Just as the inherent characteristics of copper led to its replacing old-fashioned galvanized steel and cast iron, the significant benefits of flexible PEX-a have made it an ideal solution for meeting the demands of historical renovation.

Manufactured with the Engel method, which results in a very high degree of molecular crosslinking, PEX-a offers exceptional durability and flexibility. That flexibility, combined with the availability of PEX-a in long coils, eliminates many of the fittings and connections required in rigid metal- and plastic-plumbing systems. Fewer fittings means less material, less installation labor, and fewer potential leak points, all resulting in more efficient installs at lower costs.

Ringgold happily put these advantages to work in all of the renovation jobs he has managed for Palmer Mechanical in recent years. His own first encounter with PEX-a came eight years ago at the behest of the new owner of a hotel in downtown Tulsa. Re-piping that building’s entire plumbing system with PEX-a, Ringgold estimated his labor costs were half what they would have been had he replaced copper with copper.

“Once we got on the project, we discovered we could re-pipe the building at a faster pace than the rest of the trades could renovate the rooms,” he recalled. “By the end of the project, I was a true believer.”

With their special demands and limited space, the subsequent renovation projects he managed for Palmer only strengthened his conviction. Ringgold had previously done plumbing-service work in many of these projects, so he was familiar with their peculiarities and understood how a full-fledged gut renovation with a sharp eye on history would only lead to bigger construction hurdles.

The spectacular lobby at the Mayo reflects its history in authentic style. The PEX-a pipe used for the new plumbing system was installed with minimal damage to the existing structure.

The Mayo

The most impressive example is the Mayo, also located in downtown Tulsa. Built in 1925 by brothers Cass A. and John D. Mayo, the original 18-story tower housed 600 guest rooms—each with its own ceiling fan, a major selling point— and served as a gathering place for Tulsa high society and visiting dignitaries and celebrities. (Oilman J. Paul Getty once made the Mayo his full-time home.) In 1980, the venerable hotel achieved recognition on the National Register of Historic Places, even as it struggled to regain its fading, grand-hotel luster.

Following the last of several botched attempts at restoration, the Mayo sat idle for nearly two decades until 2001, when the Snyder family bought it for $250,000. Their vision was to restore its special character and former glory. The final result is now an elegant mix of hospitality and residential spaces, with 102 hotel rooms and 70 apartments ranging from 450 to 1,200 sq. ft. and offering views of the nearby Arkansas River, the BOK Center, and downtown Tulsa.

In its own way, the Mayo’s refurbished infrastructure is as impressive as its restored interiors and exterior. Galvanized-steel mains deliver cold water to each floor of the hotel, with the run-outs to the living spaces made of AquaPEX PEX-a pipe furnished by Uponor North America, St. Paul, MN. Each residential space has its own water heater, although hot water for hydronic space heating is delivered by one of the boilers located in a basement mechanical room. This setup entails two piping systems on each floor–domestic hot water and space heating–each made of PEX-a and running from each residential unit to one of two nearby mechanical rooms on each level.

“We installed about 70,000 feet of AquaPEX for the plumbing system and another 51,000 feet of Wirsbo hePEX for the hydronic heating and cooling runs,” reported Ringgold, who led a 20- to 25-man crew during an installation process that spanned five months. It is important to note that the Wirsbo hePEX (also manufactured by Uponor North America), features a special oxygen barrier to protect ferrous components in the system from corroding through contact with oxygen in the water.

A lot of pipe

All of this piping—nearly 23 miles worth—had to be stacked or racked with the electrical, fire-sprinkler, venting, and communications lines in chases concealed inside the 9-foot-high ceilings above the hallways on each floor. The dimensions of these overhead chases, Ringgold estimates, were only “three or four feet wide and four or five inches in depth,” hardly big enough for a grown man to crawl through, let alone one charged with making leak-free pipe connections.

“That’s where PEX-a really comes into play for us,” said Ringgold. Installing long, straight runs of PEX-a pipe of as much as 140 feet within these cramped quarters was challenge enough. The saving grace: The PEX-a pipe required no connections since the pipe comes in coils up to 1,000 feet in length. Using straight lengths of copper would have required soldering a pipe joint every 20 feet.

“Shoehorning an installer into those little spaces with a torch would’ve been just asking for trouble. Why mess with fire in tight spaces, especially one with hard, plasterboard ceilings?” asks Ringgold, who figures that using copper would have boosted installation costs by as much as 30%.

PEX-a perks

The special characteristics of PEX-a pipe also deliver other time- and money-saving advantages in a large and complex renovation project such as the Mayo.

The Parlor Room’s stone floor conceals a network of PEX-a piping that provides radiant heating to the room and the rest of the hotel.

Bend instead of break. Ringgold recalled one especially difficult part of the installation in which the layout called for routing plumbing lines through an attic area above the hotel ballroom. This space was “jammed with electrical gear,” so his crews needed to circle the lines around the equipment. With copper, every change in direction necessitates cutting the pipe and soldering two connections. With PEX-a, which has the smallest bend radius of any type of PEX, it’s simply a matter of bending the pipe in the desired direction. In this instance, the ease-of-use advantage had benefits beyond speed, given the precarious location of the attic above a set of stairs.

“Instead of trying to sweat copper connections while perched 25 to 30 feet in the air over a stairwell,” Ringgold said, “we were able to maneuver a continuous length of PEX-a pipe through the hangers in much less time and with less hazard and cost.”

Swift, sure connections. In places where pipe joints are unavoidable, making them is relatively easy when installers capitalize on the natural ability of PEX-a to expand and contract, using an ASTM F1960 cold-expansion connection. One of the simplest, strongest, and most reliable connections available, it involves four simple steps:

  1. Cut the pipe with a plastic-pipe cutter.
  2. Place a PEX-a expansion ring on the end of the pipe.
  3. Expand the pipe and the ring with a Milwaukee ProPEX M12 or M18 expansion tool.
  4. Insert the larger-diameter fitting.

The pipe and ring will then immediately and naturally begin contracting back to their original shape, compressing tightly against the primary and secondary fitting barbs with as much as 7,800 pounds of radial force. There’s no deburring, torches, flux, solder, cements, or curing or cooling time.

The resulting permanent connection holds tight in tests of as much as 1,000 pounds of pull force. In addition, since the pipe is expanded before the fitting is inserted, it’s impossible to dry-fit the connection, eliminating the possibility of incomplete fittings and the resulting blow-off leaks. As Ringgold noted, “The flexibility of PEX-a gave us not only much more maneuverability for the install, but also far fewer chances for problems post installation.”

Superior heat retention. The Mayo project was Palmer Mechanical’s first experience using PEX-a pipe for heating and cooling lines, and Ringgold was impressed by the fact that his crews did not need to insulate the pipe. Not only does PEX-a resist condensation on cold-water lines better than copper, but it also offers superior heat retention in hot-water supply runs. At the Mayo, the system-temperature levels were such that no insulation was needed. “That saved a lot of installation time as well,” said Ringgold.

The voice of PEX-perience

Todd Ringgold offers some tips for plumbing and mechanical contractors looking to tackle a large historical renovation:

Familiarize yourself with the relevant rules and regulations. A smart contractor becomes thoroughly familiar with what local authorities will allow and then plans the project accordingly, down to minute details. On occasion, these rules may seem to border on pure fussiness, but that doesn’t mean a contractor will have much luck arguing his way free of them. “At the Mayo, for example, they told us exactly where we could position cleanouts—and the hallways were definitely off limits!” Ringgold recalled. “They also specified the paint color for the windows. Sounds like small stuff, I know, but that’s how seriously they take the issue of historical authenticity. There were no cleanouts in the hallways of the original structure, so there mustn’t be any in the renovated building either.”

Leave yourself some “wiggle room” in your budgeting for surprises. In fact, a contractor can pretty well count on more than one close encounter with the entirely unexpected. That comes with the territory when doing historical renovations, warns Ringgold. “You don’t know what you’re up against until you start opening up the building. Then it may be too late.”

Ringgold believes that PEX-a is the way to go for plumbing and heating systems. Although he embraced PEX-a quickly after his initial experience in 2005, he knows that some contractors, engineers, and owners remain unconvinced.

Among those working with the tools, the biggest objection he has encountered has been an aesthetic complaint: It’s not as pretty as copper—an objection that Ringgold finds bewildering considering the economic arguments for PEX-a, including the comparatively high and rising cost of copper. That cost, in turn, makes copper a prime target for jobsite theft.

Still, some of the trades remain skeptical of plastic in general for reasons beyond appearance. Many of these professionals hesitate because of their long, negative memories of polybutylene (PB) and the problems failed PB systems caused builders and installers around the country in the early 1990s. But the problems of gone-but-not-forgotten PB have nothing to do with PEX-a, which was first commercialized in Europe in the 1970s and came to North America in 1984.

Ringgold pointed to the length of the warranty for PEX-a versus copper: In Uponor’s case, that protection extends 25 years on AquaPEX pipe and the ProPEX fittings installed by a factory-trained professional. “What copper producer offers that kind of warranty?” he asked. “For me, it provides so much peace of mind.”

The most important assurance of all for Ringgold is the trouble-free performance of the systems. “We have seen no problems and no complaints with the PEX-a systems on any of these historical-renovation projects, including the very first one that served as our learning curve. Their system still runs like a top.”


Jayson Drake is the director of plumbing and fire safety at Uponor North America, St. Paul, MN.

more information