Vapour Barrier Installation Miller Edmonton

Poly and air sealing in Miller before the board goes on

A vapour barrier only works as a continuous plane. In Miller 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
• Seams lapped at framing and sealed, not just taped
• Left ready for inspection before boarding
• Electrical boxes poly-hatted and sealed
• Window and door returns detailed properly
• Poly on the warm side of the insulation

Vapour Barrier Installation Miller Edmonton

Inspecting it before it is covered

Miller drywall in context

Never two barriers

Warm side, always

Basement walls, where the rules change

Where poly is the wrong choice

Inspection, and leaving it visible

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

Vapour Barrier Installation Miller Edmonton: your questions answered

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 Miller renovations quite often have both, and finding that before boarding is worth the hour.

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.

Will this stop water coming through my basement wall?

No, and installing it would hide the evidence. Water coming through a wall is a drainage and waterproofing problem. Vapour control manages moisture in the air, not liquid water, and we will say so rather than board over it.

Will this pass inspection?

It is built to what the code asks for on your permit, and we leave it visible and sequence to your inspection date rather than boarding ahead. If an inspector raises something, we want the note directly so it is fixed from the actual reason.

Does it matter where the sheets overlap?

Yes. A lap must land on solid framing and be sealed with acoustical sealant compressed between layers. An unsupported lap taped across a cavity flexes with pressure changes and works loose.

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.