Canadian Provinces typically adopt the National Building Code of Canada (NBCC) as their provincial codes; however, some Provinces and Municipalities may add additional information reflecting modifications to meet local needs and concerns. Compliance with the code is achieved by complying with the acceptable solutions of Division B of the code. Division B, lays out the steps that must be followed, beginning with the geographic location where the build is taking place. The following are frequently asked questions regarding code compliance for the 936 Connect Wall Weatherization System.
1. Can a Part 9 building be constructed in Canada with rigid foam plastic insulation sheathing in lieu of plywood, OSB or
Yes! Article 220.127.116.11. Required Sheathing Table 18.104.22.168.-A, Wall Sheathing and Thickness and Specifications lists permitted materials for use as sheathing in a Part 9 building. Polystyrene, expanded polystyrene (EPS) Types 1 and 2, meeting the CAN/ULC – S701.1 Material Standard are permitted in lieu of plywood, OSB and gypsum sheathing in a Part 9 building.
2. Does the NBCC require 2×6 studs when constructing a Part 9 building?
No! Article 22.214.171.124. Stud Size and Spacing Article 126.96.36.199. Stud size and Spacing in the NBCC, defines stud size and spacing allowed in Part 9 construction. Table 188.8.131.52. lists supported loads, minimum stud size, maximum stud spacing and the maximum unsupported height (of the stud), for use in interior and exterior walls. For exterior walls supporting a “Roof with or without attic storage plus one floor”, 2×4 studs, spaced 16” O.C., to a maximum unsupported height (length of the wall stud) of 3.0 meters, are permitted for use in a Part 9 building.
3. Is polyethylene required for use as a vapour barrier in Part 9 construction?
No! Article 184.108.40.206. Vapour Barrier Materials Thermally insulated, heated buildings must have a vapour control layer incorporated into the building envelope (exterior walls) of a building, to prevent water vapour diffusion from the interior of the building, entering into the wall spaces. Article 220.127.116.11. of the NBCC describes a vapour barrier as a material having a vapour permeance, not greater than 60 ng/(Pa.s.m2) and requires it to be installed on the interior (warm side) of insulated walls, floors and roof spaces. Sentence four [18.104.22.168.(4)] permits the use of coatings to the drywall, such as vapour barrier paints with a vapour permeance ranging from between 45-60 ng/(Pa.s.m2) to act as the vapour control layer of the building envelope, in lieu of six mill poly.
4. Is an Air Barrier required in Part 9 Construction?
Yes? Article 22.214.171.124. Required Barrier to Air Leakage and 126.96.36.199. Air Barrier System Properties. An air barrier is required in wall, ceiling, and floor assemblies separating a heated space from an unconditioned space. Air barrier systems must create an effective barrier to air infiltration and exfiltration when exposed to a differential air pressure, from, stack effect, mechanical system’s or wind. Materials used as an air barrier must have an air leakage of not greater than 0.02 L /(s.m2) measured at a pressure difference of 75 pascals (Pa), when tested in accordance to ASTM E 2178.
Note: Quik-Therm performed two ASTM 2178 air permeance tests – one with laminates not breached and the other with laminates breached. The results from both tests met the requirements of an air barrier, as outlined in Section 188.8.131.52. in Division B, of the NBCC.