Homeowners' desire for greater flexibility between indoor and outdoor spaces is driving demand for larger window and door openings that allow for unobstructed views and access to the outdoors, a trend that is spurring the expansion of the multi-panel sliding and folding door category. Offering an alternative to installing several separate patio doors in a row, multi-panel doors utilize a series of hinged or sliding panels to completely open up a broad expanse of wall. Each panel slides or folds against its neighbor, typically stacking at the end of the door opening or disappearing into a wall pocket.
The category is experiencing a growth spurt as companies such as Jeld-Wen, Weather Shield, Marvin Windows & Doors, Loewen, and Eagle Windows & Doors/Vista Pointe have entered the multi-panel door market.
With the exception of Nana Wall Systems, the category originator that has been offering these systems for more than a decade, multi-panel sliding or folding doors have been previously primarily available through custom shops. To make these premium-style products more mainstream and feasible from a volume manufacturing standpoint, a few companies have standardized their multi-panel door systems' features and options rather than offering full custom design and fabrication.
“We utilize some components common in our other doors. It allows us to manage our costs so the standard-sized [multi-panel] product is extremely competitive,” says Dave Koester, brand manager for Weather Shield. Jeld-Wen does the same, according to Shane Meisel, the company's product marketing manager.
Loewen, Marvin, and Eagle/Vista Pointe are offering more customizable services and options, but even they have set certain limitations for their systems.
Standardized or not, multi-panel sliding and folding doors still require greater attention to the structural opening in which they will be installed, which must be designed to accommodate the type of system chosen.
Lead times for the products vary, especially among manufacturers still producing them on a somewhat custom basis, where lead times can run up to 11 or 12 weeks, sometimes longer. Standardized systems allow Jeld-Wen and Weather Shield to shorten their lead times to four to six weeks, the companies say.
Many of the manufacturers mentioned are currently either in testing for or exploring requirements for design pressure (DP) ratings and impact-resistance on their multi-panel door systems; Nana Wall is the only company with listed DP ratings at this time. Determining performance ratings and meeting coastal code requirements will be key to further expanding the market for multi-panel doors.
Manufacturers advise that installation is not as difficult as it might appear, and they all offer installation training and support for their multi-panel systems. “Installed sales dealers worry, because it looks intimidating, but we provide people to help install the first system and once [dealers] have installed one, they see how easy it is,” assures Meisel.
The most important thing is to get the unit exactly plumb, level, and square in the opening, according to Ebrahim Nana, president of Nana Wall.
Educating your customers, working with them and the manufacturer from the beginning of the project, and getting the necessary installation training are keys to success with multi-panel sliding and folding doors.