Vapour Barrier Installation Granville Edmonton

Vapour barrier details in Granville that pass inspection

A vapour barrier only works as a continuous plane. In Granville the failures are almost never the sheet itself — they are the electrical boxes, the top and bottom plates, the window returns and the penetrations, where the poly is cut and not resealed.

• Window and door returns detailed properly
• Left ready for inspection before boarding
• Electrical boxes poly-hatted and sealed
• Poly on the warm side of the insulation
• Rim joists air-sealed before insulating
• Seams lapped at framing and sealed, not just taped

Vapour Barrier Installation Granville Edmonton

Windows, doors and the returns around them

Granville drywall in context

The rim joist and the bottom plate

Inspecting it before it is covered

Where the barrier meets the ceiling and the floor

Laps, and the framing member behind them

What a vapour barrier is not

Simple, clean, on schedule — Vapour Barrier Installation in Granville Edmonton

Vapour Barrier Installation Granville Edmonton: your questions answered

Is poly always the right answer?

No. Some assemblies, such as insulated concrete basements or walls with exterior rigid insulation, are designed to dry inward, and poly stops that. We look at the whole assembly rather than defaulting.

What about outlets on exterior walls?

Each one is a deliberate hole. They need poly hats or airtight boxes sealed to the sheet. Taping poly to the front of an ordinary box does not last once board is fastened over it, and it is the most common leak we find.

Does it matter where the sheet meets the ceiling and floor?

It is the whole job. Left loose at the top or bottom plate, warm air simply goes over or under a perfectly installed sheet. The junction into a vaulted ceiling is the most commonly skipped and the wettest point in the room.

What if there is already a vapour barrier in the wall?

We tie into it, and we check whether there is a second one somewhere that would trap moisture between the two. Older Granville renovations quite often have both, and finding that before boarding is worth the hour.

Is the vapour barrier the same as an air barrier?

Not by itself. Poly slows vapour diffusion; sealed properly it also slows air, and unsealed it does very little of either. The sealing is what turns a sheet of plastic into a working assembly.

Why is there staining around my window reveals?

Usually the vapour barrier return at the window was torn or tucked rather than sealed. It is a cold junction, so condensation shows there first — often as staining or mould at the reveal.