The Experiment

The table below lists the test walls, the materials used, and the motivation for the choice. Some of the ten wall test panel assemblies have been chosen to represent conventional construction practices from the past 40 years while others are designed to investigate the role of specific assembly layers, and to test possible solutions.

Assembly Name	Motivation	Wall	Description
Early 2x4 (R-8 kraft paper)	Typical of 1960s (before major problems)	E1 W1 N1 S1	1/2” drywall with paint kraft paper, face stapled R-8 fiberglass batt 2x4 KD wood frame 3/8” plywood single 30 minute paper 3/4” stucco (3D view)
Energy Efficient (air-tight, 6 mil poly)	Typical of 1980s & 90s (beginning of problems)	E2 W2 N2 S2	1/2” drywall with paint 6 mil poly, sealed R-20 fiberglass batt 2x6 KD wood frame 1/2” OSB single 30 minute paper 3/4” stucco (3D view)
Energy Efficient (air-tight drywall, no poly)	Similar to 1980s & 90s but latex paint vapor barrier (role of the vapor barrier)	E3 W3 N3 S3	1/2” drywall with paint R-20 fiberglass batt 2x6 KD wood frame 1/2” OSB single 30 minute paper 3/4” stucco (3D view)
Energy Efficient (6 mil poly, 3/4“ cavity)	Modern rainscreen wall incorporating ventilated 3/4” cavity (current solution)	E5 W5	1/2” drywall with paint 6 mil poly, sealed R-20 fiberglass batt 2x6 KD wood frame 1/2” OSB double 30 minute paper 3/4” cavity w/ backer board 3/4” stucco (3D view)
Energy Efficient (no poly, SBPO)	Modern wall incorporating drainage space in lieu of 3/4” cavity (alternate drain systems)	E4 W4 N4 S4	1/2” drywall with paint R-20 fiberglass batt 2x6 KD wood frame 1/2” OSB Corrugated SBPO 3/4” stucco (3D view)
Energy Efficient (no poly, 3/4“ cavity)	Rainscreen wall with latex paint vapor control (role of poly)	E6 W6	1/2” drywall with paint R-20 fiberglass batt 2x6 KD wood frame 1/2” OSB double 30 minute paper 3/4” cavity w/ backer board 3/4” stucco (3D view)
Fiber Cement Board, Strapped (no poly, 3/4” cavity)	As stucco rainscreen wall but with no poly	N5 S5	1/2” drywall with paint R-20 fiberglass batt 2x6 KD wood frame 1/2“ OSB SBPO 3/4” cavity Fiber Cement Board (back primed) (3D view)
Fiber Cement Board, Direct (no poly, direct applied)	As stucco drained wall but with no poly	N6 S6	1/2” drywall with paint R-20 fiberglass batt 2x6 KD wood frame 1/2“ OSB SBPO Fiber Cement Board (back primed) (3D view)
(no poly, OSB, XPS insulation)	Drained stucco wall with exterior insulation and wood sheathing.	E7 W7	1/2” drywall with paint R-20 fiberglass batt 2x6 KD wood frame 1/2” OSB Corrugated SBPO 1” XPS 3/4” stucco (3D view)
Exterior Insulated (no poly, no OSB, XPS insulation)	Drained stucco wall on exterior insulation, no wood sheathing	N7 S7	1/2” drywall with paint R-20 fiberglass batt 2x6 KD wood frame 1” XPS Corrugated SBPO 3/4” stucco (3D view)

Monitoring of the test walls started on November 7, 2005 at the beginning of the cool and wet period in the region. The performance of the systems will be tracked. Depending on the results, intentional and well-defined leaks may be added to the walls through a wall wetting system incorporated into the test panels during their construction.

The facility contains 6 roof test bays. Three test roofs will be monitored: one typical ventilated attic and two unvented cathedralized attics with spray foam. The goal of this part of the research program is to demonstrate the performance of cathedralized attics in this climate zone versus ventilated attics.

Progress reports will be prepared at least twice per year, but BSI will collect and review data more often.