Air and Vapour Barriers Georgina

We review elevations and details to map the continuous plane around walls, roofs, foundations, windows, doors, louvers, balconies, structural steel, service penetrations, and temporary openings. Sheet, self-adhered, fluid-applied, or mechanically fastened systems are installed at specified thickness, lap, pressure, fastening, and cure conditions, with corners and penetrations detailed before broad field areas.

The governing document set is the 2024 Ontario Building Code and its Part 5 environmental separation requirements, referenced Canadian test standards in the project specification, approved envelope details, and manufacturer installation criteria. Transition materials must be chemically compatible with adjacent roofing, waterproofing, glazing, sealants, insulation, and fire-stopping products. Adhesion tests confirm preparation and primer selection.

The price responds to membrane type, wall area, transition density, substrate condition, access, winter protection, opening count, penetration count, wet-film testing, mockups, and coordination with windows, roofing, masonry, and cladding. Incompatible primers, sealants, and membranes can soften or detach. Submittal review and field mockups establish a compatible assembly before production installation.

The controlling schedule factors are substrate release, weather, primer and cure time, opening installation, roofing and cladding sequence, consultant review, access removal, and protection from follow-on work. We review elevations and details to map the continuous plane around walls, roofs, foundations, windows, doors, louvers, balconies, structural steel, service penetrations, and temporary openings.

Yes. Exterior access, odour, overspray, and opening work are controlled by elevation and zone. We coordinate shutdowns only where penetrations or active air intakes require isolation. Cold, damp, dusty, or weak substrates produce adhesion loss and blistering. We test the surface, follow temperature and moisture limits, and reject unsuitable areas until corrected.

We record substrate acceptance, adhesion tests, batch and weather conditions, wet-film or dry-film checks, lap and transition review, repairs, concealed-work signoffs, and specified air-leakage testing support. Continuity is reviewed at shelf angles, parapets, curtain-wall anchors, masonry ties, slab edges, roof curbs, foundation tops, and service penetrations before insulation and cladding conceal the work.

Provide architectural and envelope drawings, wall sections, specifications, membrane schedule, opening and penetration counts, substrate types, access plan, testing requirements, construction sequence, and target enclosure dates. Substrates are checked for soundness, dryness, temperature, sharp projections, voids, and contamination. Gaps and transitions are made ready with compatible primers, fillers, backers, and transition membranes.

An air barrier limits bulk air movement, while a vapour barrier or retarder limits water-vapour diffusion through materials. One layer can perform both functions, but some assemblies use separate materials selected for drying direction and enclosure design.

Roofs, foundations, windows, doors, slab edges, balconies, anchors, and penetrations interrupt the field membrane and concentrate movement and sequencing conflicts. Small discontinuities at these interfaces can dominate whole-building air leakage.