Wall Panels

Wall panels are the staple of our prefab panel offering, and are involved in all of our prefab packages.

Collective Carpentry wall panels are always designed with high performance building principles of energy efficiency, durability, health, comfort, and embodied carbon in mind. They typically far exceed requirements from local building regulations, and always take into account local climate factors, client desires for insulation performance, and optimization for the prefabrication process.

While we remain flexible to collaborating on the wall panel design, and in building any custom wall panel that meets our standards for the above high performance building principles, we have also found two main approaches to be the most successful, cost-effective, and efficient wall panels we can design, prefabricate, and install.

1. The “I-Joist” wall

The I-joist wall uses an open framed structural wall followed by an airtight (seams taped) plywood layer and a cavity of densepacked cellulose encapsulated by 9 ½”, 11 ⅞”, 14”, or 16” I-joists, and finished with a reinforced, airtight, monolithic, vapour open housewrap, and a layer of ¾” to 1 ½” rainscreen strapping.

In this wall, the structure sits on the outside edge of the building’s footprint, while the I-joist is an “outrigger” that hangs outward from the building. This wall is efficient to build, and ideal for both our installers as well as the trades that follow for the ability to place hold-downs and plumbing/electrical in a fully open cavity without affecting the primary airtight layer during the installation of those items.

Inboard to outboard:

2×4 or 2×6 framed structural wall on 16” or 24″ centers (batt insulation optional, on-site, and by others, R-14 or R-22)
1/2″ or 5/8″ plywood, taped airtight (primary air and vapour control layer, and for racking strength)
9 1/2″, 11 7/8″, 14” or 16” I-joists, with densepack cellulose (thermal bridge-free continuous insulation layer), R-35, R-44, R-52, or R-59
Optional – 5/8″ exterior gypsum board sheathing (for particularly fire-prone areas or buildings in close proximity to neighboring structures)
Pro Clima Mento 1000 airtight monolithic WRB (secondary airtightness, weather protection) / Pro Clima Mento Plus airtight reinforced monolithic WRB (to hold cellulose), taped airtight
3/4″ – 1 1/2″ vertical rainscreen strapping (& optional ¾” to 1 ½” horizontal rainscreen strapping)

Total R-value: R-35 to R-82 (depending on joist thickness and interior site-applied insulation used)

Typical finished wall R-value: R-57 (nominal)

While our wall panels are designed with windows, exterior finishes, interior services, and interior finishes in mind, these items are not included in Collective Carpentry wall panels and are installed on site by others, with the exception of windows and doors which are sometimes installed on site by the CC install team, on a case by case basis. ¾” plywood bucks and approved headers and additional structure for windows and doors are always installed in the shop, integrated into airtight layers, and included in CC wall packages. All window rough openings are prepared with cedar sill shims and a peel and stick sill pan treatment.

2. The “C-Joist” wall

The C-joist wall optimizes the structural design and material use and offers a lower total R-value with similar advantages in continuous insulation and panel installation as the I-joist wall. With an 8″ shop-fabricated C-joist in place of the larger standard I-joist sizes, and a 2×4 interior structural service wall @24″OC, the insulation value once the interior service wall is insulated reaches R-43.6. The 2×4 is made stronger for vertical loading and lateral shear by virtue of its inclusion in what is called a “mid-ply panel”, where 1/2″ sheathing is sandwiched on either side by dimensional lumber, with nails connecting all three elements at regular spacing. The 2×4 wall is delivered open and uninsulated, the plywood layer (with seams taped) acts as the primary air and vapor control, and the 8″ C-joist is filled with densepacked cellulose (recycled newspaper) insulation. The assembly is finished with a reinforced, airtight, monolithic, vapour open housewrap, and a layer (or two) of ¾” to 1 ½” rainscreen strapping.

In this wall, the inner C-joist chord typically lines up with the outside edge of the building’s footprint, while part of the C-joist cavity “hangs off” as an outrigger from the building, planing down to exterior insulation installed outside of foundation stem walls, slab on grade, etc. This wall is efficient to build, and typically costs 25-30% less than the I-joist wall.

Inboard to outboard:

2×4 framed structural wall on 24″ centers (batt insulation optional, on-site, and by others, R-14)
1/2″ plywood, taped airtight (primary air and vapour control layer)
8″ C-joist, with densepack cellulose (thermal bridge-free continuous insulation layer), R-30
Pro Clima Mento Plus reinforced airtight monolithic WRB (cellulose containment, secondary airtightness, weather protection), taped airtight
3/4″ – 1 1/2″ vertical rainscreen strapping (& optional ¾” to 1 ½” horizontal rainscreen strapping)

Total R-value: R-30 to R-43

While our wall panels are designed with windows, exterior finishes, interior services, and interior finishes in mind, these items are not included in Collective Carpentry wall panels and are installed on site by others, with the exception of windows and doors which are sometimes installed on site by the CC install team, on a case by case basis. ¾” plywood bucks and approved headers and additional structure for windows and doors are always installed in the shop, integrated into airtight layers, and included in CC wall packages. All window rough openings are prepared with cedar sill shims and a peel and stick sill pan treatment.