Keeping up with a popular home building trend can be a challenge, especially when the trend depends on extra planning, specifying, and installation care. A good example of that is homeowners’ growing demand for large window walls.
Surging home buyer interest along with today’s more energy-efficient windows have made a mulling solution more popular than ever. A recent survey of U.S. homeowners revealed 92% favor a home with abundant natural light. Combining window assemblies is a smart, affordable way to keep up with the trend.
However, attaching windows together to form an aesthetically pleasing, energy-efficient window wall system can present certain challenges.
1. Uncertain Structural Performance. As window assemblies grow larger, structural performance comes into question. How does the assembly handle wind loads and air and water resistance? How does it perform in a coastal environment?
2. AAMA 450 Certification Confidence. Does the window wall meet American Architectural Manufacturers Association (AAMA) standards? Has it been tested to minimize callbacks and the even more costly possibility of litigation from installing an unproven assembly?
3. Difficult Field Conditions. Field mulling is seldom ideal. Materials, weather conditions, and lack of assembly stations often work against the level of precision and craftsmanship expected from factory mulling.
4. Ordering Confidence. “What did I forget?” is an understandable question when ordering mulling sealants, fasteners, clips, mull caps, and other accessories. With so many parts, something is bound to be forgotten, which then causes delays.
5. One-Stop Resource. Wouldn’t it be great if you had an architectural detail manual (ADM) that presented all the manufacturer’s performance-tested mulling options in one place, complete with tributary width and span detail?
For every residential architect, developer, builder, general contractor, subcontractor, and installer who has faced one or more of these issues, there’s good news, says Jeff Siverhus, a senior product manager with Marvin® Windows and Doors. The Minnesota-based window and door company has spent the past 18 months developing a comprehensive mulling solution.
First-Of-Its-Kind Mulling Solution
Marvin’s approach was introduced in January at the International Builders’ Show in Orlando. Siverhus says it was well-received by home building professionals.
“We’ve worked hard to address builders’ window wall concerns,” says Siverhus. The company’s focus on providing architects with AAMA 450 certification transparency can help a designer determine if a particular window wall assembly achieves code before the order system.
For example, Marvin’s new ADM features dozens of performance charts across 11 assembly types. While the International Building Code requires either physical testing or calculations to determine performance ratings, both determine Marvin’s performance grade (PG) ratings. Each chart in the ADM presents mullion performance ratings based on their high internal standards, showing a PG of 20, 30, 40, or more. The dual determination presents a more accurate picture of the mull material’s allowable stress. That insight offers designers and specifiers more design range and ordering confidence, saving time and trouble.
The all-inclusive assembly solution also helps speed construction timelines by incorporating all of the necessary fasteners, clips, caps, and other parts, which reduces specifying time and the risk of missing parts and lost time at the jobsite.
When Field Mulling Is Required
Marvin recognizes many window wall projects ship in subassemblies that must be mulled at the jobsite. As such, the company is about to release its Prep for Field Mull option, which means window walls that won’t fit on a truck if mulled in a factory will be delivered in large sub-assemblies. “All mull components that can be applied in the factory will be. All necessary components are automatically included in the order and cut to length for quick on-site assembly. Just follow the instructions and the assembly is AAMA 450-certified,” explains Siverhus of the process.
Home builders looking for a simpler, more confident way to meet homeowners’ window wall needs now have a proven win-win solution, says Siverhus. “It’s time home builders had a surprise-proof mulling option that installs easily and performs great,” he adds. Click here to learn more and download the new 2018 ADM.