Should I use poly or a smart membrane?

Most straightforward Sherwood 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.

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.

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.

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.

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.

Vapour Barrier Installation Sherwood Edmonton | 6 Mil Poly

Poly and air sealing in Sherwood before the board goes on

A vapour barrier only works as a continuous plane. In Sherwood 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.

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

Top plates, bottom plates and the perimeter

The edges do the leaking

The continuous joints at the top and bottom of an Sherwood 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.

Sherwood drywall in context

About Sherwood

Annexed to the City in 1964, Sherwood was once part of the Town of Jasper Place.

What we see in Sherwood

In Sherwood 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.

Renovations, and meeting an existing barrier

Continuity across old and new

In an Sherwood 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.

Sealing at the electrical boxes

Every box is a hole

An outlet or switch on an exterior Sherwood 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.

The rim joist and the bottom plate

Two cold junctions

In an Sherwood basement the rim joist and the bottom plate against concrete are where warm air meets cold most directly. Both need sealing before insulation, not after.

Sequencing

Once the insulation and poly are on, neither can be reached without pulling the wall apart. We deal with them first, and we would rather flag a problem there at the quote than discover it behind a finished wall.

Warm side, always

The one rule everything else follows

The barrier goes on the heated side of the insulation. In an Sherwood 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 Sherwood build the sheets are planned so that laps fall on studs rather than wherever the roll ran out.

How it works

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

Free quote

We come out to your Sherwood 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 Sherwood 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 Sherwood 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 Sherwood 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 Sherwood 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 Sherwood 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 Sherwood Edmonton.

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FAQ — Vapour Barrier Installation Sherwood Edmonton

Vapour Barrier Installation Sherwood Edmonton: your questions answered

Should I use poly or a smart membrane?: Most straightforward Sherwood 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.
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.
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.
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.
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.

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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.

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Vapour Barrier Installation Sherwood Edmonton

Poly and air sealing in Sherwood before the board goes on