Does my basement development in Cornerstone need a vapour barrier?

Yes, essentially always -- our climate means a Cornerstone exterior basement wall gets a barrier on the warm side of the insulation before drywall goes on. The requirement for your Cornerstone assembly is confirmed in person on the visit, not guessed from the plan.

Which side of the insulation does the poly go on in a Cornerstone home?

The warm side of the assembly -- the one looking into the heated Cornerstone room. More than anything else on a Cornerstone job this gets reversed, and it cannot be corrected after boarding.

Do you seal the outlet boxes and vents in Cornerstone?

Yes -- each and every outlet, switch box, vent and pipe going through a Cornerstone wall is sealed on its own. Hanging poly over open boxes in Cornerstone framing gives you the look of a finished barrier without the performance.

Do I still need a vapour barrier in Cornerstone if I have spray foam?

Sometimes it should not go on at all -- some spray foam assemblies in Cornerstone homes are already the barrier, and poly over them is the wrong move. It varies with product and thickness, so we verify it on site in Cornerstone instead of assuming.

Can you do the vapour barrier and the drywall together in Cornerstone?

Yes -- running insulation, barrier and boarding as a single Cornerstone job is our usual approach, and it puts one crew on the hook for what ends up in the wall. We also cover Central Heights, Crystal Ridge, Downey Ridge and the Okotoks area.

Call (403) 829-8702 Free Quote

Vapour Barrier Cornerstone

Vapour Barrier Installation Cornerstone Okotoks

Poly Vapour Barrier Cornerstone

Basement Vapour Barrier Cornerstone

Vapour barrier installation in Cornerstone, Okotoks — 6 mil poly sealed over insulation before drywall, lapped at the seams and sealed at every penetration.

Emplastrum Drywall 5-Star Google Reviews

Trustpilot

Get Your Free Drywall Quote

Tell us about your project — we’ll get right back to you, 7 days a week.

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.

Free on-site quotes7 days a weekNW Calgary · NE Calgary · SW Calgary · SE CalgaryLocally owned & operatedThe Go-To Drywall Contractor for Repair, Restoration & Finishing

Vapour barrier installation in Cornerstone, sealed before the board goes on

Few parts of a Cornerstone build are as completely concealed, or as unforgiving, as the vapour barrier; once boarded, a torn sheet or unsealed box is permanent. In Cornerstone we install and seal 6 mil poly over the insulation on the warm side, lapped at the seams and sealed at every penetration, before any board goes up. Cornerstone is an Okotoks residential community, so basement development insulation is the main call here, with the main floors already insulated to a recent code. We cover Cornerstone, Central Heights, Crystal Ridge, Downey Ridge and the Okotoks area, 7 days a week.

Vapour barrier installation in Cornerstone basements and renovations
6 mil poly on the warm side of the insulation in Cornerstone
On Cornerstone work the laps land on framing and get sealed, not just fastened
Outlet boxes, vents and plumbing penetrations sealed in Cornerstone
Rim joist and window returns detailed properly
Kept visible for inspection in the Cornerstone home ahead of the drywall stage
Cornerstone coverage — we come to you

What affects the cost of vapour barrier installation in Cornerstone?

Area, penetrations and detailing

Vapour barrier cost in Cornerstone depends on the wall and ceiling area being covered, the number of penetrations that need sealing — outlets, vents, pipes and light boxes — and how much detail work the rim joist and window returns need. We measure the space and give a fixed price before we start.

Usually priced with the insulation

Most Cornerstone vapour barrier work is quoted together with the insulation and the boarding that follows it, because it is the same crew and the same visit. Housing in Cornerstone is mixed, which is why we look before we quote rather than after.

Vapour barrier placement in a Cornerstone home, and why it is not negotiable

The warm side, always

In Cornerstone the barrier goes on the warm side of the insulation — the side facing into the heated Cornerstone room. That is how indoor moisture is prevented from moving into a Cornerstone cavity and condensing on cold framing.

What goes wrong when it is reversed

Installed cold-side, the barrier traps moisture within the assembly rather than keeping it out. It is one of the few mistakes in a Cornerstone wall that cannot be corrected without opening the wall back up, which is exactly why we check every Cornerstone job before anything is covered. In Cornerstone we see everything from original finishes to recent renovations on the same block.

How we install and seal it in Cornerstone

Hung, lapped and sealed

We run the poly in the largest sheets the space allows to keep seams to a minimum, lap every seam over a stud or joist rather than in open cavity, and seal it — a stapled overlap on its own is not a seal.

The penetrations are the job

Outlet and switch boxes, bath fans, dryer vents, plumbing stacks and pot lights each get sealed individually in your Cornerstone home. Where poly is on the walls but the boxes behind are open, the barrier does not work; it is the commonest fault we find on part-finished Cornerstone jobs.

Common vapour barrier situations in Cornerstone

In Cornerstone, cornerstone is a residential neighbourhood in Okotoks. Build years vary across the neighbourhood, so rather than assume what is behind the wall we confirm it on site — the finish, the texture and how the existing surface has aged all change how the repair is approached. One fixed price after an honest on-site look, and the job done right the first time.

Why Cornerstone homeowners have us do the vapour barrier

We are the ones boarding over it

As a drywall company we install the barrier the way we want to board over it, because we are the trade that has to live with what is behind the sheet in Cornerstone.

Left ready to be looked at

We leave the barrier complete and visible so it can be inspected before the drywall goes on — nothing gets covered until it has been seen.

Fixed price, same-day reply

We cover Cornerstone and the Okotoks area, 7 days a week. On-site quoting in Cornerstone costs nothing, and the price is set before anything starts. Housing in Cornerstone is mixed, which is why we look before we quote rather than after.

How it works

Simple, clean, on schedule — Vapour Barrier Installation in Cornerstone Okotoks

Free quote

The quote happens at your Cornerstone Okotoks home, in front of the work. We measure, we look at what is behind the wall where it matters, and the price we give is the price.

Book a day

Scheduling is settled in one conversation. The vapour barrier installation start date in Cornerstone Okotoks is confirmed and the team turns up on it.

The work

The vapour barrier installation is done in a protected work area. Furniture and floors in the Cornerstone Okotoks home are covered, and nothing is left for you to clean up at the end of the day.

Walk it with you

You sign off, not us. We go through the completed vapour barrier installation with you at the Cornerstone Okotoks home and fix anything that is not right that day.

Reviews

Rated by Okotoks Homeowners

★ ★ ★ ★ ★

For vapour barrier installation in Cornerstone Okotoks, Emplastrum Drywall handles the repair, the restoration and the finish. What Okotoks homeowners think of that work is on our Google profile.

Go through them, then judge us on your own Cornerstone Okotoks project.

Read our reviews on Google

FAQ — Vapour Barrier Cornerstone

Vapour Barrier Cornerstone: your questions answered

Does my basement development in Cornerstone need a vapour barrier?: Yes, essentially always -- our climate means a Cornerstone exterior basement wall gets a barrier on the warm side of the insulation before drywall goes on. The requirement for your Cornerstone assembly is confirmed in person on the visit, not guessed from the plan.
Which side of the insulation does the poly go on in a Cornerstone home?: The warm side of the assembly -- the one looking into the heated Cornerstone room. More than anything else on a Cornerstone job this gets reversed, and it cannot be corrected after boarding.
Do you seal the outlet boxes and vents in Cornerstone?: Yes -- each and every outlet, switch box, vent and pipe going through a Cornerstone wall is sealed on its own. Hanging poly over open boxes in Cornerstone framing gives you the look of a finished barrier without the performance.
Do I still need a vapour barrier in Cornerstone if I have spray foam?: Sometimes it should not go on at all -- some spray foam assemblies in Cornerstone homes are already the barrier, and poly over them is the wrong move. It varies with product and thickness, so we verify it on site in Cornerstone instead of assuming.
Can you do the vapour barrier and the drywall together in Cornerstone?: Yes -- running insulation, barrier and boarding as a single Cornerstone job is our usual approach, and it puts one crew on the hook for what ends up in the wall. We also cover Central Heights, Crystal Ridge, Downey Ridge and the Okotoks area.

Other Drywall Services in Cornerstone Okotoks — Taping, Mudding, Ceilings & Painting

We cover Cornerstone Okotoks as part of our wider Vapour Barrier Installation Okotoks service, across Okotoks — see every neighbourhood we work in, or talk to your drywall contractor in Okotoks.

All services↗

Drywall & Ceilings

Drywall Repair Cornerstone› Drywall Patching Cornerstone› Ceiling Repair Cornerstone› Water Damage Drywall Cornerstone› Poly-B Repair Cornerstone› Plaster Repair Cornerstone› Drywall Installation Cornerstone› Drywall Boarding Cornerstone› Basement Drywall Cornerstone› Renovation Drywall Cornerstone› New Construction Drywall Cornerstone› Legal Suite Drywall Cornerstone› Garage Drywall Cornerstone› Taping & Mudding Cornerstone› Level 4 Drywall Finish Cornerstone› Level 5 Finish Cornerstone› Skim Coating Cornerstone› Texture Matching Cornerstone› Popcorn Ceiling Removal Cornerstone› Knockdown Ceiling Removal Cornerstone› Ceiling Texture Cornerstone› Acoustical Ceiling Installation Cornerstone› Soundproofing Cornerstone› Fire-Rated Drywall Cornerstone› Drywall Removal & Demolition Cornerstone›

Framing

Framing Cornerstone› Metal Stud Framing Cornerstone›

Insulation

Insulation Installation Cornerstone› Batt Insulation Cornerstone› Loose Fill Insulation Cornerstone› Attic Insulation Cornerstone› Acoustic Insulation Cornerstone›

Painting

Interior Painting Cornerstone› Ceiling Painting Cornerstone› Basement Painting Cornerstone› Renovation Painting Cornerstone› Drywall Repair & Painting Cornerstone› Popcorn Ceiling Removal & Painting Cornerstone›

Related areas

We also serve nearby

Other services in Okotoks

Need Okotoks’s go-to drywall contractor for repair, restoration and finishing? One trusted team for boarding, taping, finishing, repairs & renovations — start to finish.

Your Drywall Contractor in Okotoks →

One trusted team, the whole job

Poly-B repair, drywall & painting in Cornerstone Okotoks

Poly first, then board — see Basement Drywall Cornerstone Okotoks.

Insulation not in yet? Start at Insulation Installation Cornerstone Okotoks.

Cornerstone — full service list

Everything else we handle in Cornerstone

From the Blog

Drywall Tips & Guides — Cornerstone Okotoks

Basement drywall boarded and finished by Emplastrum Drywall in Calgary

August 6, 2026

Drywall in Calgary: The Complete 2026 Homeowner Guide

Drywall in Calgary covers board choice, finishing levels, repairs and paint. This guide walks a homeowner through every stage of drywall in Calgary.