IN DEPTH: Insulation and Housewrap

IN DEPTH: Insulation and Housewrap

Originally published in LBM Journal, January’s 2016, In Depth

As codes tighten, dealers evaluate their options and expand their product choices to meet the growing needs for energy, air, moisture and noise control.

Structural Insulated Panels (SIPs)

LBM JournalSIPs are growing in awareness due to the variety of functions they can provide in one component.  They consist of a foam-core center sandwiched between two layers of OSB panels, creating a thermal sandwich panel.  The result is a highly efficient building envelope.  “SIPs are a little bit different mousetrap that works better, but it takes a long while to convince dealers of that,” says Joe Pasma, technical manager for Premier Building Systems.

The panels can produce high energy efficiency that can provide long-term savings for homeowners.  And because they combine structural panels with insulation, they can sharply reduce the time it takes to frame a house and minimize the number of activities needed to be completed on-site.

“It creates a turnkey solution for builders that may be viewed by some as a little ahead of its time,” says Bob Murphy, manager of product development at Universal Forest Products, the distributor for Atlas’ ThermalStar products.  “In reality, it is a better way to build an exterior envelope, covering exterior walls with an all-in-one, easy-to-install product that provides a water-resistant barrier, air barrier, breathable layer of rigid closed-cell EPS insulation and a mailable structural component with no structural defects.”

Figuring the panels’ cost can be challenging, says Pasma, because the initial cost is misleading.  “There are so many variables both in what the SIPs will cost (based on size and insulating value) and the savings that accrue in other areas by using them.  SIPs affect all portions of construction and create savings and benefits in many areas for many trades.”  They can lead to the ability to downsize HVAC systems, he suggests, sometimes by as much as 50%.  “That drastic decrease can create opportunities for changing the system to a mini-split or other more efficient design.”

Premier’s panels are custom-made with all openings and penetrations cut before delivery, ensuring they can be erected quickly.  Deliveries typically take three to four weeks once shop drawings are approved by the builder.  Dealers order them as they do trusses, he notes.

R.S. Means studies show the panels can save builders 40% in construction-material costs and 60% in labor costs, Murphy says.  “The labor savings in particular is significant, especially as some markets have a labor shortage.  The key is that once you’ve erected the panels, you’ve got the structural material and the continuous insulation in place immediately.”

Builders need to make some minor adjustments when they use SIPs – or any continuous exterior insulation, notes Murphy, Door and window-jamb extensions and door threshold extensions need to adapt to the additional thickness of the walls, and structural tie-downs should be fasted on the wall’s interior or before the panels are installed.  “Builders have told us this is not a big deal after the first job,” he says.

The panels make up only about 2% of the market currently.  There’s lots of room to grow,” says Pasma.  “They produce high energy efficiency, creating a huge savings, and that’s becoming a driving force for homebuyers.  Combined with the onsite labor savings – in an era when skilled labor is so tough to find – its easy to understand why more builders and dealers are looking closer at this approach.”

Read more in LBM Journal to learn more about insulation and house wrap options: