Vapour Barrier Installation Evergreen Edmonton

Vapour barrier details in Evergreen that pass inspection

A vapour barrier only works as a continuous plane. In Evergreen 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.

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

Vapour Barrier Installation Evergreen Edmonton

Seams belong on framing

Evergreen drywall in context

The rim joist and the bottom plate

Electrical boxes, the usual failure point

Where poly is the wrong choice

Inspecting it before it is covered

Windows, doors and the returns around them

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

Vapour Barrier Installation Evergreen Edmonton: your questions answered

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.

Can you install the barrier if someone else did the insulation?

Yes, but we check the insulation first. A barrier over a poorly filled cavity locks the problem in, and once the board is on neither can be corrected without opening the wall.

Is a basement wall done the same way as an upstairs wall?

No. A basement wall can take moisture from the ground too, so poly detailed like an above-grade wall can trap moisture against the concrete. The insulation is held off the concrete so the wall can dry, with vapour control on the warm side.

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.

Is it a problem to have poly on both sides?

Yes. Two barriers trap moisture between them with no direction to dry. It is a real mistake we still find in renovated Evergreen walls, and it stays invisible until the damage shows.

Do the electrical boxes really need sealing?

They are the most common failure point. Every outlet in an exterior wall is a cut in the plane, and unsealed it is a direct path for moist air into the cavity at the coldest part of the wall.