Question 1

What are the vapour barrier requirements for a newly built home in Fredericton under the 2020 NB Building Code?

Accepted Answer

The 2020 NB Building Code requires a vapour barrier with a permeance rating of 60 nanograms per pascal-second per square metre (ng/Pa·s·m²) or less on the warm side of all insulated building assemblies in Fredericton. In practical terms, this means 6-mil polyethylene vapour barrier installed on the interior face of exterior walls, under attic insulation, and on the warm side of any insulated assembly.

Specific Installation Requirements for New Construction:

The vapour barrier must be continuou

Question 2

Should I install an HRV after air sealing my home in Edmundston NB? | Insulation IQ?

Accepted Answer

The short answer is almost certainly yes — and in Edmundston specifically, it's one of the most important decisions you'll make for your home's long-term health and comfort.

Edmundston sits in the Madawaska region of New Brunswick, firmly in climate zone 6, with design temperatures regularly reaching -30°C and heating seasons that stretch from October through April. The combination of extreme cold and an air-sealed envelope creates conditions where a Heat Recovery Ventilator (HRV) isn't just a

Question 3

What causes condensation on windows in insulated New Brunswick homes? | Insulation IQ?

Accepted Answer

Condensation on windows is one of the most common complaints from New Brunswick homeowners after an insulation upgrade — and it's frequently misdiagnosed as a window defect or a sign that the new insulation is "not working." In most cases it is neither. Understanding what's actually happening requires a quick review of the physics of moisture and dew point in a cold-climate building.

When warm, humid interior air contacts any surface cooled below its dew point temperature, the moisture in the a

Question 4

Can I use spray foam as both insulation and air barrier in my NB home? | Insulation IQ?

Accepted Answer

Yes — and in New Brunswick's climate zone 6, this dual-purpose capability is one of the most compelling reasons contractors and energy-conscious homeowners reach for closed-cell spray polyurethane foam (ccSPF). When properly applied, closed-cell spray foam simultaneously fills every crack and void in the assembly, becomes the air barrier, and delivers high R-value insulation — all in a single product and a single trade visit.

The NB Building Code (which adopts the National Building Code of Cana

Question 5

How do I know if my New Brunswick home has adequate air sealing? | Insulation IQ?

Accepted Answer

Most New Brunswick homeowners don't know their home has an air sealing problem — they just know it feels drafty in January, their heating bills seem high, and some rooms are never quite comfortable no matter how the thermostat is set. The connection between those symptoms and air leakage through the building envelope often goes undiagnosed for years, quietly costing hundreds of dollars per winter.

The definitive test is a blower door test, performed by a certified energy adviser as part of an E

Question 6

Should I seal the vapour barrier to the foundation wall in a NB basement? | Insulation IQ?

Accepted Answer

This question gets at one of the more nuanced points in residential building science — the answer depends on whether you are working on a poured concrete wall with a polyethylene vapour barrier system or a different type of assembly, and it matters considerably in New Brunswick's climate zone 6 context.

Let's start with the most common scenario: a homeowner in Moncton, Fredericton, or Saint John finishing a basement, with a poured concrete or concrete block foundation wall, adding interior fram

Question 7

How do I air seal my attic hatch or pull-down stairs in Quispamsis? | Insulation IQ?

Accepted Answer

The attic hatch and pull-down stair opening are two of the most notorious air leakage points in any New Brunswick home — and they are particularly overlooked because they sit in a closet or hallway and are easy to ignore. In Quispamsis and the broader Kennebecasis Valley area, where homes range from 1970s-era split-levels to newer two-storey builds, addressing these openings is one of the highest-return air sealing tasks a homeowner can undertake. The energy penalty is real: an unsealed attic ha

Question 8

How do I air seal a dropped ceiling or soffit in my Oromocto home? | Insulation IQ?

Accepted Answer

Dropped ceilings and interior soffits are among the most significant hidden air leakage pathways in New Brunswick homes, and they are surprisingly common in the split-levels, raised bungalows, and 1970s-era homes that dominate Oromocto and the surrounding military community. Addressing them properly requires getting into the attic and treating these cavities as the major thermal and air bypasses they really are.

To understand why dropped ceilings are such a problem, you need to visualize what t

Question 9

What is the NB Building Code requirement for vapour barriers in new construction? | Insulation IQ?

Accepted Answer

New Brunswick has adopted the National Building Code of Canada (NBC) 2015 with provincial amendments, and its vapour barrier requirements for new residential construction reflect the demands of a climate zone 6 heating environment. Understanding these requirements is essential for any builder, general contractor, or homeowner overseeing new construction in Moncton, Fredericton, Saint John, or anywhere else in the province.

The core requirement is found in NBC Part 9 (Housing and Small Buildings

Question 10

Can too much air sealing cause indoor air quality problems in NB homes? | Insulation IQ?

Accepted Answer

Yes, and this is one of the most important questions any New Brunswick homeowner can ask before starting a serious air sealing project. The short answer is: a very tightly sealed home without a deliberate mechanical ventilation strategy can absolutely develop indoor air quality problems. This is not a reason to avoid air sealing — it is a reason to air seal properly and plan for ventilation at the same time.

The concept is captured in the building science phrase "build tight, ventilate right."

Question 11

What is the best caulk or sealant for air sealing in cold NB climates? | Insulation IQ?

Accepted Answer

Choosing the right caulk or sealant for air sealing in New Brunswick isn't one-size-fits-all — the best product depends on the joint type, the surrounding materials, whether the application is interior or exterior, and whether fire protection is required. Using the wrong product in a cold climate like Zone 6 can mean premature failure, cracking, and air leakage that returns within a few years.

Acoustical sealant (also marketed as acoustic caulk or resilient sealant) is arguably the most importa

Question 12

Does my Saint John home need a vapour barrier on exterior walls? | Insulation IQ?

Accepted Answer

The short answer is: almost certainly yes, especially if your Saint John home has wood-framed walls with batt insulation and you're working from the interior. But the fuller picture involves understanding what a vapour barrier actually does, where it goes, and when alternatives might perform better in Saint John's specific climate.

Saint John sits in Climate Zone 6 under the National Building Code of Canada framework, with a heating season that regularly produces interior-to-exterior temperatur

Question 13

How do I seal air leaks around plumbing and electrical penetrations in NB? | Insulation IQ?

Accepted Answer

Plumbing and electrical penetrations are among the most consistently overlooked sources of air leakage in New Brunswick homes, yet they're often straightforward to seal once you know the right approach and materials. In a typical older home in Fredericton or Moncton, dozens of small gaps around pipes, wires, and conduits can collectively add up to the equivalent of leaving a window open all winter — not an exaggeration when you consider how many penetrations a typical house has through the attic

Question 14

Should I use 6-mil poly vapour barrier in my Moncton home walls? | Insulation IQ?

Accepted Answer

In Moncton and across New Brunswick, the 6-mil polyethylene vapour barrier has been the standard wall assembly component for decades, and for good reason — but whether you need it, where to install it, and how to install it correctly all depend on your wall assembly, insulation type, and renovation scope.

New Brunswick sits firmly in Climate Zone 6, one of Canada's more demanding heating climates. Moncton averages around 4,400 heating degree-days, with winters that push moisture from the warm i

Question 15

Can air sealing alone reduce my heating bill in New Brunswick? | Insulation IQ?

Accepted Answer

Yes — and the savings can be surprisingly significant. Air sealing is often overlooked because it's invisible once complete, but in a leaky New Brunswick home, it can reduce heating costs by 15% to 40% depending on how drafty the building is to begin with. In some older homes in Fredericton, Moncton, or Saint John built before the 1980s — when air tightness simply wasn't part of the building culture — air sealing alone can be one of the highest-return investments available.

To understand why, c

Question 16

What is the difference between a vapour barrier and an air barrier in NB construction? | Insulation IQ?

Accepted Answer

These two terms are often used interchangeably in casual conversation, but in building science — and in the National Building Code as adopted in New Brunswick — they refer to distinct and separate control layers with different functions. Confusing them leads to assemblies that fail at one job or the other, and in New Brunswick's Climate Zone 6 winters, both jobs matter enormously.

An air barrier controls the movement of air through a building assembly. Air carries moisture, heat, and pollutants

Question 17

How do I air seal my attic before adding insulation in New Brunswick? | Insulation IQ?

Accepted Answer

Attic air sealing is one of the highest-return energy upgrades you can do in a New Brunswick home — and it must be done before insulation is added, not after. Blowing cellulose or fibreglass over a leaky attic floor without sealing the penetrations beneath is like putting a thick blanket over a screen door: the insulation adds R-value on still days but does almost nothing to stop the convective heat loss that drives most energy waste in New Brunswick's Climate Zone 6 winters.

The first step is

Question 18

Where are the most common air leaks in a New Brunswick home? | Insulation IQ?

Accepted Answer

Air leakage is the silent energy thief in most New Brunswick homes. Unlike insulation quality, which you can assess by looking at R-values on a spec sheet, air infiltration is invisible — until you book a blower door test and watch the smoke pencil drift toward a gap you never knew existed. Understanding where these leaks typically occur is the first step toward a warmer, drier, and more energy-efficient home.

The attic hatch is consistently one of the worst offenders in older NB homes. A stand

Question 19

Do I need a vapour barrier when insulating my Fredericton basement? | Insulation IQ?

Accepted Answer

Whether you need a vapour barrier in a Fredericton basement depends on how you're insulating it, where the insulation is placed, and what moisture conditions your particular foundation presents. It's not a simple yes-or-no — but with a clear picture of how moisture moves through basement assemblies, you can make the right call for your home.

The core principle is this: vapour moves from warm, humid air toward cool, dry air. In a New Brunswick winter, that means vapour is trying to push from the

Air Sealing & Vapour Barriers