A Light in the Attic


A Light in the Attic

Looking for an economical way to add square footage and an alternative to decreasing spans? Read on!

Old tires, scrap lumber, kids toys and holiday decorations—for most home owners, these are the types of things relegated to the attic or rafter area above the garage. However, a new idea on the horizon may spell the end to such underutilization of space. It’s a trend that is putting a new face on a tried and true product: the attic truss. To understand why attic trusses are witnessing a new surge in sales, particularly on the East Coast, we need to look first at the impact of Southern Pine design value changes, then at how component manufacturers are able to address emerging builder needs through attic trusses. We’ll then look at the prospects for this trend to continue.

attic truss layout

Instead of being used just over garages for storage, they are now being used in third floor “walk-up” designs.

Southern Pine Design Value Changes

In January 2012, the American Lumber Standards Committee (ALSC) approved the first major devaluation of lumber design values in over two decades. The devaluation was limited to visually graded 2x4 #2 Southern Pine (SP) and lower grades. While ALSC also instituted a precedent-setting, six-month implementation period, the impact was dramatic for the roof truss industry. “While we had plenty of advance notice to let our customers know about the change and to prepare for it, there was still a lot of fear of the unknown,” said Terry Gonya at 84 Lumber in Charlotte, NC.

“Nearly every house produced in the region had 2x4 #2 and #3 involved in its design and production,” added Gonya. The market was left wondering how the decline in design values would materially affect the market. Because the devaluation only applied to visually graded lumber, many wondered if there would be a shift toward machine stress rated or machine evaluated lumber (MSR/MEL). Others, including many lumber producers in the region, were convinced there would be a shift and purchased MSR machines to address that expected shift in demand. However, a dramatic shift to MSR has yet to occur.

The second piece to the puzzle occurred in January 2013, when the ALSC adopted a second round of SP design value changes that actually slightly improved the strength values of #2 2x4s, but lowered the design values of all other grades and sizes of SP, including 2x6, 2x8 and 2x10 boards. “We were better prepared for the changes in design values this time around, and the price impact was tempered by a declining SP market,” said Gonya.

The SP devaluation in 2012 impacted longer span trusses and scissor trusses. “We found out that, in some cases, it was less expensive to change a top or bottom chord to 2x6 instead of a higher grade of 2x4,” said Gonya.

Bob Dayhoff of Shelter Systems in Westminster, MD, agreed, adding, “The SP changes this year had an impact on long span floor trusses, typically increasing the amount of board feet needed to design the project due to the lumber value reductions in the higher SP grades.”

attic trusses in yardRoof girders and attic trusses were not immune to the changes either. “With girder trusses, you can add a ply or change a bottom chord from a 2x6 to a 2x8,” said Gonya. “The 2013 design value changes potentially impacted traditional attic trusses the most because the top and bottom chord of the attic trusses were generally 2x6 and greater already,” said Gonya. “With this year’s changes, instead of increasing the dimensional size of the chords, you had to decrease span.”

The alternative? Make the bottom chords out of parallel chord trusses (see photo). That subtle change opens up a whole set of possibilities.

Selling Attic Trusses

The uses and designs of attic trusses have changed over the past few years. “It used to be the attic truss was used primarily for a bonus room over the garage or for a stand-alone garage with room above,” said Gonya. These attic trusses generally had a 2x8 or 2x10 bottom chord with a 2x6 or 2x8 top chord. This meant that the size of the room created within the attic truss was restricted by the span value of the bottom chord. “Typically, you were looking at a maximum room span of around 16 feet,” he said. A span that grew even smaller with the SP devaluation this year.

The new style attic trusses are being built with a web pattern in the floor system in place of the 2x10 bottom chord. Gonya observed, “This change enables us to increase the room size to over 20 feet, depending on the overall span of the trusses.” Travis Ness of R&R Components in York, PA, agreed, “Attics make a lot of sense for spans over 16 feet. With bottom-chord webbing, the interior room span can be anywhere from 20-24 feet.” As a result, attic trusses can be more versatile in meeting the needs of builders.

Instead of being used just over garages for storage, they are now being used in third floor “walk-up” designs. In other words, an additional stairwell is added to the home layout, and the attic area is finished to be used as regular living space. “One of the only things that change with a walk-up attic is that the roof pitch typically will increase from a 6/12 pitch to an 8/12 pitch in order to accommodate higher interior walls,” said Ness. The added depth of the bottom chord of these new attic trusses also makes it easier to match the floors to I-joist or floor trusses used in multi-story homes when adding rooms above attached garages that much easier to do. In other words, the added depth insures both the ceiling on the first floor and the floor on the second match seamlessly, without the need for building up either in the field. It also creates greater depth for insulation.

The overall trend in housing during the downturn was a return to small floor plans. However, the attic truss presents an opportunity to add more livable square footage back into the house without increasing the overall dimensions of the home. “With the decrease in total square footage, builders and owners want to maximize the space they have,” said Ness. “It’s cheaper to add it in the attic.”

“Typically, when a builder introduces a new model, we have the opportunity to sell them on using attic trusses instead of stick building it,” said Gonya. “It gives us a chance to provide some value engineering and give them something they want.”

The energy code is also driving the push for greater energy efficiency, not only during the construction of the home, but over its operational life. Even if homebuilders aren’t looking to add living space, attic trusses are a great way to address this trend. “Attic trusses allow for easy installation of HVAC mechanicals and ductwork into conditioned space, which adds a lot to their efficiency,” said Dayhoff. “That can be particularly valuable for duplexes and townhomes, but are increasingly applicable to single-family units.”

“Particularly in Maryland, a big trend is to place the HVAC mechanicals in the attic,” said Ness. “These attic trusses are not necessarily for living space, but make moving around and working on the equipment easier after the house is finished.” This solved a big issue for builders, who found that building officials were not approving how the HVAC equipment was installed prior to using attic trusses.

“An additional factor that helps us promote attic trusses to builders is that they will need less interior bearing walls than if they were stick-built,” said Gonya. “Which will save them time and money.” Ness explained further, “A lot of builders who come to us are looking to reduce internal bearing throughout the house. They are using engineering floor systems with long spans for the first floor and can’t place internal bearing locations on that floor.”

Ness added, “Builders increasingly want to be as lean as possible in the construction of a home. While it may cost more for the attic trusses, they can more than make up for it through savings in time and labor at the site by turning a house over from conventional framing and eliminating internal bearing walls.”

Will It Continue?

“I think, in our part of the country, this trend will definitely continue,” said Gonya. “Most homes in our area are built on a slab foundation, so storage and extra space are always something that people need more of.” When you think about it, without a basement, the only place to get more storage is by going either up or out. With the ‘up’ already there for the taking, it seems an easy sell.

“Our customer base is rather mature when it comes to attic trusses. They’ve been using them heavily in many of their homes for years,” said Ness. “Out of the fifteen roof truss stackers we have running in our yard, at any given time, we may have four that have attic trusses on them.”

Both Gonya and Dayhoff agreed, the greatest obstacle will always be the added cost. “Attic trusses are more than just a common truss,” said Gonya. “However, to sell it, you have to point out that the cost-to-square-footage is really low.” Possibly as low as $1,500 to add one to two extra rooms on to a house. Spread over a 30-year mortgage, that seems like a deal most homebuyers would jump at.

Hinged TrussesHinged truss drawing

Transporting attic trusses has also become a lot easier than in the past. Typically, with attic trusses, the push to maximize the interior room span meant greater roof slopes, resulting in roof trusses that could become wide load nightmares for drivers. “A few years ago, we started using hinge plates at the peaks,” explained Gonya. “You can run a 2x8 top chord up to the hinge plate, then add on roof caps in the field using the plates.”