Should I use poly or a smart membrane?

Most straightforward Calder walls are fine with 6-mil poly, continuous and sealed. A variable-permeance membrane is worth it on retrofits and some basement details because it gives the assembly a drying path in both directions.

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.

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.

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 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.

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 Calder walls, and it stays invisible until the damage shows.

Vapour Barrier Installation Calder Edmonton | 6 Mil Poly

Poly and air sealing in Calder 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
Window and door returns detailed properly
Rim joists air-sealed before insulating
Seams lapped at framing and sealed, not just taped
Left ready for inspection before boarding

Electrical boxes, the usual failure point

A hole in the plane

Every outlet and switch in an Calder 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.

Calder drywall in context

About Calder

In the early part of the 20th century, Calder was part of the Hudson's Bay Company Reserve and settled primarily by employees of the Grand Trunk Pacific Railway.

What we see in Calder

In Calder 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 Calder 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.

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

Why the warm side, and why only one

Which way the moisture moves

Through an Calder winter, warm humid indoor air pushes outward through the assembly. A vapour barrier on the warm side stops that moisture before it reaches a cold surface where it can condense.

Two barriers is worse than one

A second barrier on the cold side traps moisture between the two with no direction to dry. It is a genuine mistake we still find in renovated walls, and it is invisible until the damage shows.

Inspecting it before it is covered

Last chance to see it

Once board is on, an Calder 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.

Basement walls, where the rules change

Concrete complicates it

A Calder basement wall can take moisture from the ground as well as from the room. That is why a poly barrier detailed the way it is on an above-grade wall can trap moisture against the concrete instead of keeping it out.

How the assembly is built

Rigid insulation or a framed cavity held off the concrete gives the wall a way to dry, with vapour control on the warm side of the insulation. Getting that order wrong is the most common reason a finished Calder basement smells musty.

How it works

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

Free quote

We come out to your Calder 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 Calder 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 Calder 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 Calder 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 Calder 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 Calder 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 Calder Edmonton.

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FAQ — Vapour Barrier Installation Calder Edmonton

Vapour Barrier Installation Calder Edmonton: your questions answered

Should I use poly or a smart membrane?: Most straightforward Calder walls are fine with 6-mil poly, continuous and sealed. A variable-permeance membrane is worth it on retrofits and some basement details because it gives the assembly a drying path in both directions.
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.
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.
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 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.
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 Calder walls, and it stays invisible until the damage shows.

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Vapour Barrier Installation Calder Edmonton

Poly and air sealing in Calder before the board goes on