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.

Is a bathroom done differently?

Same rules, larger consequences. A bathroom pushes far more vapour into the wall, so a gap shows up faster. The fan housing and duct are sealed rather than trimmed around, and we check the fan vents outside rather than into the attic.

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.

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.

Can I add poly over insulation that already has a facing?

Usually no. Two retarders leave any moisture that gets in with no direction to dry. We check what is already in the wall before adding to it rather than assuming the cavity is bare.

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.

Vapour Barrier Installation Bonnie Doon Edmonton | 6 Mil Poly

Poly and air sealing in Bonnie Doon before the board goes on

A vapour barrier only works as a continuous plane. In Bonnie Doon 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.

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

Electrical boxes, the usual failure point

A hole in the plane

Every outlet and switch in an Bonnie Doon exterior wall is a cut in the poly. Left unsealed it is a direct path for moist air into the cavity, and the boxes are usually the coldest spot on the wall.

Poly hats and sealant

Boxes get a poly hat or an air-sealed box, and the poly is sealed to it rather than simply cut around. It is a small detail repeated dozens of times, which is exactly why it gets skipped.

Bonnie Doon drywall in context

About Bonnie Doon

At the turn of the 20th century, the cities of Edmonton and Strathcona were engaged in an intense rivalry to attract growth.

What we see in Bonnie Doon

In Bonnie Doon the drywall work is plaster and lath repair, popcorn and stipple ceiling removal, careful patching into original surfaces. We confirm what your home actually needs on site, in writing, before anything starts.

Warm side, always

The one rule everything else follows

The barrier goes on the heated side of the insulation. In an Bonnie Doon climate that is the room side of an exterior wall.

Why position decides everything

Put it on the cold side and you have placed a moisture stop exactly where indoor humidity will condense against it, inside the wall, where nothing dries and nothing is visible until the damage is done.

Sealing at the electrical boxes

Every box is a hole

An outlet or switch on an exterior Bonnie Doon wall is a deliberate opening straight through the barrier.

The fix

Poly hats or airtight boxes, sealed to the sheet. Taping the poly to the front of an ordinary box does not last, because the board is fastened over it and the seal breaks. This is the single most common leak we find behind finished walls.

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 Bonnie Doon build the sheets are planned so that laps fall on studs rather than wherever the roll ran out.

Renovations, and meeting an existing barrier

Continuity across old and new

In an Bonnie Doon renovation the new poly has to tie into whatever is already in the wall. A new sheet stopped at the edge of the work leaves an open seam inside the assembly.

What we look for

Whether an existing barrier is present at all, what condition it is in, and whether there is a second one somewhere that would trap moisture between the two. Older renovations quite often have both, and finding that before boarding is worth the hour it takes.

Where poly is the wrong choice

Not every assembly wants it

Some Bonnie Doon 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.

How it works

Simple, clean, on schedule — Vapour Barrier Installation in Bonnie Doon Edmonton

Free quote

We come out to your Bonnie Doon 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 Bonnie Doon 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 Bonnie Doon 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 Bonnie Doon 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 Bonnie Doon Edmonton. If anything needs a second look, we handle it before we call the job done.

Reviews

Rated by Edmonton Homeowners

★ ★ ★ ★ ★

Emplastrum Drywall is the vapour barrier installation contractor Bonnie Doon 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 Bonnie Doon Edmonton.

Read our reviews on Google

FAQ — Vapour Barrier Installation Bonnie Doon Edmonton

Vapour Barrier Installation Bonnie Doon Edmonton: your questions answered

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.
Is a bathroom done differently?: Same rules, larger consequences. A bathroom pushes far more vapour into the wall, so a gap shows up faster. The fan housing and duct are sealed rather than trimmed around, and we check the fan vents outside rather than into the attic.
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.
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.
Can I add poly over insulation that already has a facing?: Usually no. Two retarders leave any moisture that gets in with no direction to dry. We check what is already in the wall before adding to it rather than assuming the cavity is bare.
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.

Get Your Free Drywall Quote

Tell us about your project — we’ll get right back to you, 7 days a week. Prefer to call? (403) 829-8702.

Full Name / Company

Phone Number

Email Address

Area

Service Needed

I agree to be contacted by Emplastrum Drywall about my project by phone, text, or email.

No obligation. We never share your information.

📐 Plan Your Project

Estimate Your Insulation

📐 Materials Calculator

How much do you need?

Enter your room size for a quick materials estimate.

Room length (ft)Room width (ft)Ceiling height (ft)Number of rooms Include ceilingSheet sizeCoats of paintCavity depthFraming spacingInsulation already there (in)Top up to (in)Stud spacingDoorsWindowsWaste allowance (%)

Estimate only — rounded up, based on standard coverage rates (drywall +10% waste; paint ~350 sq ft per gallon per coat; batt bundles by cavity depth, less a framing factor; studs at your chosen spacing plus waste). Product coverage varies by brand — confirm quantities before buying. Ask us about the right R-value for your project.

Rather we handle it? Get a free estimate →

Vapour Barrier Installation Bonnie Doon Edmonton

Poly and air sealing in Bonnie Doon before the board goes on