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 Graydon Hill walls, and it stays invisible until the damage shows.

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.

Can you install the barrier if someone else did the insulation?

Yes, but we check the insulation first. A barrier over a poorly filled cavity locks the problem in, and once the board is on neither can be corrected without opening the wall.

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.

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.

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

Vapour Barrier Installation Graydon Hill Edmonton | 6 Mil Poly

Poly and air sealing in Graydon Hill 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.

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

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 Graydon Hill 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.

Electrical boxes, the usual failure point

A hole in the plane

Every outlet and switch in an Graydon Hill 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.

Warm side, always

The one rule everything else follows

The barrier goes on the heated side of the insulation. In an Graydon Hill 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 Graydon Hill 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.

Inspection, and leaving it visible

It gets checked before it is covered

Vapour barrier and air sealing in Graydon Hill are inspected before drywall covers them. We sequence to your inspection date rather than boarding ahead and covering something the inspector needs to see.

If it does not pass

We want the inspector's note directly. Most failures are specific — an unsealed box, a floating seam, a torn return — and they are corrected faster from the actual note than from a second-hand summary.

Poly against smart membranes

Two approaches

Standard 6-mil poly is the common choice in Graydon Hill 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 Graydon Hill Edmonton

Free quote

We come out to your Graydon Hill 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 Graydon Hill 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 Graydon Hill 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 Graydon Hill 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 Graydon Hill 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 Graydon Hill 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 Graydon Hill Edmonton.

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FAQ — Vapour Barrier Installation Graydon Hill Edmonton

Vapour Barrier Installation Graydon Hill Edmonton: your questions answered

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 Graydon Hill walls, and it stays invisible until the damage shows.
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.
Can you install the barrier if someone else did the insulation?: Yes, but we check the insulation first. A barrier over a poorly filled cavity locks the problem in, and once the board is on neither can be corrected without opening the wall.
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.
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.
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 Graydon Hill renovations quite often have both, and finding that before boarding is worth the hour.

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Vapour Barrier Installation Graydon Hill Edmonton

Poly and air sealing in Graydon Hill before the board goes on