Which side does the vapour barrier go on?

The warm side of the insulation. Through an Alberta winter moisture pushes outward from the heated space, and the barrier stops it before it reaches a cold surface where it can condense.

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 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.

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.

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.

Vapour Barrier Installation Magrath Heights Edmonton | 6 Mil Poly

Poly and air sealing in Magrath Heights before the board goes on

Alberta winters put a large vapour drive from inside to outside, so the barrier belongs on the warm side of the insulation. Getting the position right matters as much as getting it sealed: a second barrier on the cold side traps moisture in the assembly with no way to dry.

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

Where poly is the wrong choice

Not every assembly wants it

Some Magrath Heights walls, such as an insulated concrete basement or an assembly with exterior rigid insulation, are designed to dry inward, and a full poly layer stops that.

How we approach it

We look at the whole assembly rather than defaulting to poly because it is what is usually done. Where a smart or variable-permeance membrane is the right call, we say so.

Windows, doors and the returns around them

Where the detail gets fiddly

The return between a window frame and the wall in Magrath Heights is awkward, tight, and often left as a torn edge tucked behind trim.

Why it matters

It is also a cold junction where condensation shows first, usually as staining or mould at the reveal. The poly is cut to fit, sealed to the frame and supported, rather than folded and hoped for.

Top plates, bottom plates and the perimeter

The edges do the leaking

The continuous joints at the top and bottom of an Magrath Heights wall are longer than every box and lap put together, and they are the easiest to seal well or badly.

What good looks like

Sealant on the plate, poly laid into it and compressed by the framing or the board above, carried around corners rather than cut and butted at every change of direction.

Laps, and the framing member behind them

Where sheets meet

A lap needs to land on solid framing and be sealed with acoustical sealant compressed between the layers, not taped in mid-air across a cavity.

Why it fails otherwise

An unsupported lap flexes with pressure changes and the seal works loose. In an Magrath Heights build the sheets are planned so that laps fall on studs rather than wherever the roll ran out.

What a vapour barrier is not

It is not an air barrier 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.

It is not a damp-proofing fix

If a Magrath Heights basement has water coming through the wall, vapour control is not the answer and installing it will hide the evidence. That is a drainage and waterproofing problem, and we will say so rather than board over it.

Poly against smart membranes

Two approaches

Standard 6-mil poly is the common choice in Magrath Heights and works when it is continuous and sealed. A variable-permeance membrane tightens in winter and opens in summer, giving the assembly a drying path in both directions.

When it is worth the difference

Most straightforward walls are fine with poly. Retrofits, assemblies that cannot be fully sealed and some basement details benefit from a membrane. We say which we would use and why rather than defaulting.

How it works

Simple, clean, on schedule — Vapour Barrier Installation in Magrath Heights Edmonton

Free quote

We come out to your Magrath Heights Edmonton property, take a real look at the vapour barrier installation, and hand you a fixed price on the spot — no guessing, no vague ballpark. Every vapour barrier installation quote in Magrath Heights Edmonton starts with an honest, on-site assessment.

Book a day

We pick a day that works for your schedule and show up on time, ready to start the vapour barrier installation in Magrath Heights Edmonton. No back-and-forth rescheduling — once it's booked, our team is there.

The work

We keep the dust under control and protect your Magrath Heights Edmonton home while we finish the vapour barrier installation to a clean, paint-ready standard. Floors covered, doors sealed off, and the site left tidy at the end of every day.

Walk it with you

We don't pack up till you've walked the finished vapour barrier installation with us and you're happy with the result in Magrath Heights Edmonton. If anything needs a second look, we handle it before we call the job done.

Reviews

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Emplastrum Drywall is the vapour barrier installation contractor Magrath Heights Edmonton trusts for repair, restoration and finishing — rated on Google by Edmonton homeowners.

Read the reviews, or leave your own after your vapour barrier installation project in Magrath Heights Edmonton.

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FAQ — Vapour Barrier Installation Magrath Heights Edmonton

Vapour Barrier Installation Magrath Heights 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.
Which side does the vapour barrier go on?: The warm side of the insulation. Through an Alberta winter moisture pushes outward from the heated space, and the barrier stops it before it reaches a cold surface where it can condense.
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 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.
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.
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.

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Vapour Barrier Installation Magrath Heights Edmonton

Poly and air sealing in Magrath Heights before the board goes on