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.

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 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.

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.

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.

Vapour Barrier Installation Strathcona Edmonton | 6 Mil Poly

Vapour barrier details in Strathcona that pass inspection

A vapour barrier only works as a continuous plane. In Strathcona 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
Electrical boxes poly-hatted and sealed
Poly on the warm side of the insulation
Seams lapped at framing and sealed, not just taped
Left ready for inspection before boarding
Rim joists air-sealed before insulating

Poly against smart membranes

Two approaches

Standard 6-mil poly is the common choice in Strathcona 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.

Strathcona drywall in context

About Strathcona

Strathcona was named for Lord Strathcona, Hudson Bay Company Governor (1889-1914) and the man chosen to drive the "last spike" of the CPR transcontinental railway.

What we see in Strathcona

In Strathcona 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.

Where poly is the wrong choice

Not every assembly wants it

Some Strathcona 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.

Electrical boxes, the usual failure point

A hole in the plane

Every outlet and switch in an Strathcona 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.

Inspecting it before it is covered

Last chance to see it

Once board is on, an Strathcona vapour barrier is inaccessible for the life of the wall.

How we work

The barrier gets walked and repaired, every box, every lap, every penetration, before boarding is scheduled, and it is photographed. A tear found before the board goes on costs a piece of tape; found afterwards it costs a wall.

The parts an inspector looks at first

Predictable list

Electrical boxes, seams landing off framing, the top and bottom plates, window returns and any penetration. Those are where Strathcona vapour barrier inspections fail, and they fail for the same reasons every time.

Why we sequence to it

We leave the work visible and board after the inspection rather than ahead of it. Covering something an inspector needs to see costs a wall, not an afternoon.

Sealing at the electrical boxes

Every box is a hole

An outlet or switch on an exterior Strathcona 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.

How it works

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

Free quote

We come out to your Strathcona 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 Strathcona 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 Strathcona 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 Strathcona 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 Strathcona 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 Strathcona 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 Strathcona Edmonton.

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FAQ — Vapour Barrier Installation Strathcona Edmonton

Vapour Barrier Installation Strathcona 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.
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.
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 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.
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.
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.

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Vapour Barrier Installation Strathcona Edmonton

Vapour barrier details in Strathcona that pass inspection