Wall Framing System

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Choose any combination of wall, floor and roof systems to suit your style and fit your budget.  Choose a framing style based on your desire for more visible natural wood, or one that allows brighter painted surfaces.  Like the exterior of our homes, the interior of your home can be designed to have a more traditional or contemporary style based on your framing style choices.  We will work with you to decide which framing system best fits your taste and budget.

What are the advantages of our wall system?

Our unique system combines the benefits of open cavity framing and the comfort of a complete insulation wrap around the outside of the framing.  For a comparison of our wall system to a conventionally framed wall and a stress skin wall system scroll down.
 
 
Beamed Exterior Wall System (standard)
Our unique wall system takes advantage of the ease of conventional framing along with the structural and aesthetic benefits of post and beam.  Electrical wires and plumbing can be installed in a way that is familiar to contractors, saving you money.

A groove cut into the posts and beams to accept drywall eliminates the problem of gaps as the wood beams expand and contract with seasonal fluctuations in humidity. An airtight layer of Styrofoam insulation, together with housewrap around all wall sections, significantly reduces air infiltration and helps to deaden noise.  Through the use of the highest quality materials, the Habitat Post & Beam wall system achieves an R-value of 21.

 

 

Full Exposure Exterior Wall System (optional)
This framing system has a more traditional look, as most of the posts and beams are exposed to the interior. You may opt to include knee braces for the exterior wall (the angled piece shown in the picture to the left). Other than having more of the posts and beams exposed, the specifications for this wall system are the same as our standard wall system above.
Exterior Wall System Materials:

2x4s 16” on center with 1” Dow® Styrofoam bonded to 5-ply fir 1/2” CDX plywood, included for on-site application.  The factory-bonded insulation and plywood is installed on site to wrap the exterior walls and post and beam frame.  Factory rough openings are provided for exterior windows and doors.  Housewrap air infiltration barrier provided for exterior coverage.  With owner/contractor supplied high-density fiberglass insulation, this wall is designed to significantly outperform typical 2x6 wall construction.

  • Insulation - 1" Dow® Styrofoam pre-bonded to the 5-ply plywood, in combination with owner/contractor-supplied finish insulation (3 1/2" fiberglass, spray foam, cellulose, etc.) provide "thermal layering." Total R Value of 21.
  • Siding - red cedar clapboards, tongue and groove knotty cedar vertical siding, or white cedar shingles (owner/contractor to finish with paint, stain or water repellent).  
  • Trim - smooth primed cedar ready for final finish.
  • Posts - #1 Douglas fir, chosen for straightness and visual quality.  Pre-cut, notched, numbered and dadoed for drywall.

 

The Habitat Wall System vs. Conventional Wall System:

Overview -
Our wall system is designed to outperform typical conventional 2x6 wall construction. Dow® Styrofoam has an excellent pamphlet* that is available on the Web showing the benefits of using Styrofoam on the exterior of a wall, as we do with our wall system. They summarize with, "Compared to walls consisting of OSB and batt insulation, walls that incorporate Styrofoam brand insulation deliver improved insulation, reduced air infiltration and greater energy savings," and "Styrofoam brand insulation delivers superior insulation and moisture resistance. It's also Energy Star-approved, ensuring efficient performance."

There are many variables to take into account when determining the total performance of any wall system. The three main factors that are typically considered are the R-value, condensation control and air infiltration.

R-Value -
The total R-value of our wall system is higher than that of a conventional 2x6 wall and provides a tighter seal than a 2x6 wall. If you compare just the insulation values, it appears that our wall system is a slightly below a 2x6 wall. The problem with this calculation is that it does not take framing into account. The framing material used to build a conventionally framed wall accounts for an average of between 25% and 30% of the total wall volume, which leaves at least 25% of your walls with an R-Value of only 5.5.

With the Habitat wall system, all of the framing materials are covered by Styrofoam, adding much needed insulation. With a simple calculation accounting for the performance of our entire wall system, it outperforms a 2x6 wall.

Condensation -
Whether you are in a hot, cold or changing climate, moisture control is very important with all wall systems. Condensation can form inside of a wall, potentially leading to mold growth and wood rot. With our wall system, the Styrofoam becomes a moisture barrier that has a higher surface temperature, resulting in a decreased chance of condensation.

Air Infiltration -
Reducing air infiltration is extremely important so that your home is both energy efficient and draft free. The efficiency of a home drops significantly if it is not both well insulated and relatively airtight. This effect is analogous to going outside on a cold and windy day with just a wool sweater. The wind will go through the sweater and will make you cold. If you had just a windbreaker without a sweater, you would be cold. It would take the combination of both a windbreaker and a thick sweater to keep you warm. A house is the same in that you need to keep it reasonably airtight (windbreaker) and well insulated (sweater) to keep it warm inside.  

*Brochure Information:
Dow® Chemical Company
Search the Dow Web site for form #179-07978 

 

The Habitat Wall System vs. Stress Skin Wall System:

Overview -
Our wall system has many benefits compared to stress skin panels. There are many variations on this type of wall panels and many different terms for similar products (stress skin, structural insulated panel, foam core, sandwich panel, etc.). Most of the systems consist of two outer skins (typically oriented strand board) and one inner core of insulating material to form a monolithic unit. For ease of explanation we are going to use the term "stress skins" for comparison to our wall system.
 
Stress skin panels look like they are a complete and easy solution for use as a wall system. Unfortunately, there is a lot more to a wall system than just insulation and ease of installation.
 

R-Value -
Most stress skin manufacturers advertise similar R-values to both our wall system and 2x6 conventionally framed walls with high-density fiberglass.  Stress skins are available in varying thicknesses and types of foam core, resulting in a wide range of R-values.  Higher R-values can be specified, but that may not be the best use of additional expense (you can increase conventional wall R-values as well). You can more effectively increase thermal performance of your home and make it more comfortable by putting the money into areas where more heat is lost, such as additional roof insulation or higher quality windows.

Condensation -
Both our wall system and stress skin panels handle condensation very effectively by providing a complete thermal break from the framing, resulting in less chance of condensation compared to conventionally framed wall systems.
 
Air Infiltration/Emission -
Both our wall system and stress skin panels do not allow as much air leakage (drafts) as a conventionally framed wall system. Our wall is built in layers, so joints are staggered. With stress skin panels, joints line up through the entire panel.  If the manufacturer uses a poor sealing technique, or if the installer does not follow the directions closely and the seal between the panels fails, major air leakage (drafts) can occur.  Some manufacturers may still use OSB board and/or glues that contain formaldehyde, which may outgas as the panels age.
 
Nail Base -
The Habitat wall system provides solid wood studs into which nails can be attached.  One of the major issues with most stress skin panels is the lack of solid material to use as a nail base both inside and out (they are filled with foam). The Western Red Cedar Lumber Association specifies that siding and trim nails must penetrate 1 ½" into solid wood, otherwise siding can cup, pulling out the nails and loosening the trim, creating gaps that leave the exterior walls vulnerable to further damage.  On the interior of the home there is no solid nail base for attaching weighty items such as upper kitchen cabinets, flat screen TVs and large pictures or other wall hangings.
 
Wiring/Plumbing -
Installing wiring and plumbing within the Habitat wall system requires no special considerations and can be run like a conventionally framed structure.  With most stress skin walls, however, there may be some specific techniques that subcontractors will need to become familiar with.  Not all stress skin manufacturers include wiring chases, and if they do all of the wiring must be done through an existing chase, making wiring more time consuming and difficult.  All outlets and switches must be in predetermined locations, otherwise insulation must be melted out of the panel to add or change locations, compromising the integrity of the panel’s energy efficient properties and increasing labor costs.  Future communication and electrical upgrades can become difficult or impossible.  Similar issues arise when plumbing within these walls.
 
Infestation Potential -
Bugs and rodents have been found to burrow into the expanded polystyrene commonly used in stress skin panels (not the extruded polystyrene that we use), compromising integrity and insulation value of the panels and creating a host of other issues. "A few cases have been noted where insects and rodents have tunneled throughout the SIPs" (U.S. Department of Energy, consumer energy information: EREC Briefs).
 
Cost -
Because of the familiarity contractors will have with our type of wall system, building using our wall panels is inherently more cost efficient.  Stress skin panels themselves are fairly expensive, and you may also pay more for some of your subcontractors.  Due to the difficulty of working with stress skin panels (as mentioned above), many contractors will produce higher bids.  Also, "... The tendency for any subcontractor asked to bid on unfamiliar specs is to throw a high number at the job to cover the unusual." (Building with Structural Insulated Panels (SIPS) by Michael Morley p. 140).