Insulation R-Value | Canada Homeowners Guide

In the diverse climates of Canada, where temperatures can swing dramatically, the effectiveness of your home's insulation is pivotal to maintaining comfort and energy efficiency. Whether you're looking to keep warm during the chilly winter months or cool during the brief but intense summer, understanding the R-value of insulation is key.

Welcome to our exploration of R-Value and Long-Term Thermal Resistance (LTTR) in insulation. In Canada, where temperatures fluctuate often, understanding insulation R-value is crucial for ensuring energy efficiency and comfort in your home.

Selecting the right insulation based on R-value is essential to prevent air leaks, enhance energy efficiency, minimize heat transfer, and create an effective air barrier within your home or building.

This guide will explain what R-value is, why it’s important and why you should also consider a measure called Long-Term Thermal Resistance (LTTR) which predicts insulation performance over time.

Then we’ll compare the most popular insulation materials used today, and discuss R-value requirements for different parts of homes as specified in the BC Building Code.

Join us as we navigate through the intricacies of insulation and its practical applications.

What is R-Value?

R-value is an important tool for assessing energy efficiency and insulation quality in your home.

R-value measures how well a material resists heat transfer. The higher the R-value, the better the insulation against heat flow.

In extremely cold climates like Canada, having the right R-value is crucial for minimizing heat loss in winter and heat gain in summer – especially in Canadian regions with its cold winters and hot summers.

Insulation with higher R-values helps maintain a consistent indoor temperature. By reducing the workload on heating and cooling systems, good insulation contributes to reduced energy consumption, lower utility bills, and a smaller carbon footprint.

Proper insulation and air sealing can also improve indoor air quality by preventing dust, allergens, and pollutants from entering your home, creating a healthier living environment for you and your family.

Factors affecting R-Value include insulation type, density, thickness, age, and moisture accumulation.

Understanding LTTR

LTTR, or Long-Term Thermal Resistance, is a measure of insulation performance based on R-values over an extended period of time.

While R-value offers a snapshot of insulation effectiveness, LTTR considers the impacts of aging, settling, and environmental conditions, providing a more comprehensive and accurate representation of long-term R-value performance.

Insulation materials can change over time for reasons such as compression, moisture absorption, exposure to other elements, or while the product cures, all of which can influence their thermal resistance. LTTR is particularly important for materials like foam insulation, where thermal performance can degrade over time.

By using LTTR values, builders and homeowners can better predict the long-term energy efficiency of insulation products, ensuring that buildings maintain energy efficiency and a comfortable temperature throughout the years.

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Common Insulation Material R-Values

Here are some of the most common insulation materials and their associated R-values:

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R-Value Requirements in the BC Building Code

The British Columbia Building Code (BCBC) specifies the thermal performance and R-value requirements of building envelopes, which can vary significantly between BC municipalities.

Additionally, the BC Step Code influences specific R-value targets adopted by each municipality.

Attic Upgrades

The recommended attic insulation R-value is R-50 or higher.

Proper attic insulation R-value helps maintain a comfortable indoor temperature and reduces energy consumption significantly.

Upgrade your attic insulation to improve energy efficiency, prevent heat loss, and enhance overall comfort in your home.

We offer various insulation materials and installation methods suitable for attics of all sizes in the Okanagan Valley, BC – including poly & batt, blown-in fibreglass, and spray foam.

Exterior Wall Insulation: R-24

The minimum R-Value for exterior wall insulation in BC is 15.8 to 21.9, depending where you live. We recommend an insulation R-value of R-24 or higher for exterior walls.

Insulating your exterior walls with the proper R-value is crucial for minimizing heat & cooling loss for better energy efficiency, and regulating indoor temperatures for comfort.

Crawl Spaces & Basement Insulation: R-20/R-20+

Insulating crawl spaces and basements is critical for maintaining energy efficiency and preventing moisture-related issues.

For crawl spaces, it's important to consider insulating both the walls and floor to create a thermal barrier. This helps regulate temperatures and minimize heat loss.

When insulating from the outside (exterior insulation), the recommended R-value is R-20 or higher. This level of insulation helps create an effective thermal envelope and prevents heat loss.

In basements, insulating both the walls and the basement slab is recommended. You have the option to insulate your basement and crawl space walls from either the exterior or the interior, depending on your specific needs and circumstances.

If insulating from the inside (interior insulation), the recommended R-value for interior basement walls is R-20.

Additionally, combining interior insulation with exterior insulation of at least R-4 further enhances energy efficiency and thermal performance.

Garage Insulation: R20

Insulating your garage walls and ceiling can significantly improve energy efficiency and comfort, especially if your home has an attached garage. The standard recommended R-value for garage walls is R20, providing adequate insulation to maintain a stable indoor temperature and prevent heat loss from adjacent living spaces.

However, if you plan to heat the garage, we recommend matching the R-value of the insulation in the house's exterior ceiling, typically around R50. This ensures consistent insulation levels throughout your home, minimizing energy waste and optimizing heating efficiency.

It's essential to note that garage doors are often the biggest source of heat loss in most garages. They typically have low R-values, gaps along the edges, and account for a significant portion of the garage wall square footage. Consider upgrading your garage door or adding insulation to reduce heat loss and improve energy efficiency.

Floor Insulation: R20-40

While the BC Building Code doesn't detail specific R-values for floors, insulating floors above unheated spaces like crawl spaces or garages is crucial. Adding insulation under the floor helps maintain consistent indoor temperatures and minimizes heat transfer.

For floors below living spaces, we recommend R28-R40 insulation, while floors below decks should have R20-R28 insulation. In most cases, we advise homeowners in BC to insulate crawl space walls rather than the floor. However, if they opt to insulate the floor, we suggest R20-R40 insulation for optimal thermal performance. Contact us for expert guidance on floor insulation tailored to your home's needs.

Interior Walls

The BC Building Code does not mandate specific R-values for interior walls, as they are generally not insulated for thermal purposes.

Interior walls primarily serve as partitions between rooms and do not require the same level of thermal insulation as exterior walls. Therefore, thermal insulation is not typically installed in interior walls unless there are specific soundproofing or fire protection requirements.

Vapor Barriers and Air Sealing

Proper installation of vapor barriers and air sealing materials is essential for maximizing insulation effectiveness and energy efficiency.

Vapour barriers play a crucial role in preventing moisture from entering the insulation. This helps maintain the integrity and thermal resistance value of the insulation material over time.

Also, air sealing ensures there are no gaps or leaks in the building envelope, which can lead to heat loss and reduced insulation performance. By sealing air leaks, you can enhance the overall energy efficiency of your home and improve indoor comfort.

Choosing the Right Insulation for Your Home

Now that you understand the significance of R-value, LTTR, and CSA testing methods, how do you choose the right insulation for your home? Here are some key considerations:

• Climate Zone: Consider your region's climate to determine the recommended R-values for different areas of your home, such as walls, ceilings, and floors.
• Insulation Type: There are various insulation materials available, including fibreglass, loose fill, foam board, and spray foam. Each type offers different R-values and benefits, so choose one that suits your needs and budget.
• Installation Quality: Proper installation is critical for maximizing insulation performance. Work with experienced professionals such as OKI to ensure optimal results.
• Energy Efficiency Goals: If your goal is a high energy-efficient home and long-term savings, investing in insulation with higher R-values and LTTR can pay off significantly over time.

The Authority on R-Values in Canada: CSA

To evaluate the R-value and LTTR of insulation materials, the Canadian Standards Association (CSA) uses rigorous tests like the Steady-State Thermal Resistance Test.

The Steady-State Thermal Resistance Test typically involves placing a sample of the insulation material between two plates.

One side of the sample is exposed to a heat source, while the other side faces a cold surface or ambient air.

When the temperature difference between these two surfaces creates a heat flow through the insulation sample, instruments such as heat flux meters or thermal conductivity analyzers measure the heat flow.

You can calculate the R-value of an insulation material by quantifying the heat transfer and temperature differentials. CSA uses the unit Kelvin·square-metre per Watt (K·m²/W) to express R-Value.

The test is a reliable and consistent method for determining the R-value of insulation materials under controlled conditions and is always conducted following standardized procedures outlined by the Canadian Standards Association (CSA) in CAN/ULC-S770.

How Thermal Bridging Affects R-Values

Thermal bridging occurs when heat passes through conductive materials in a building's envelope, effectively bypassing the insulation.

Thermal bridging can reduce the overall energy efficiency of a structure and lead to an effective decrease in R-value.

Typically, thermal bridges are found at junctions where different building materials meet, such as around windows, doors, rafters, studs, and where the foundation meets the walls.

Such areas often have lower resistance to heat flow compared to the surrounding insulation, making them weak points for energy loss.

For example, if a wall is insulated to an R-value of R-20, but includes substantial thermal bridging through studs, the effective R-value could be much lower than 20.

Studies have shown that thermal bridging can reduce a wall’s effective R-value by more than 50% depending on the extent and nature of the bridges.

To combat the effects of thermal bridging, some projects apply continuous insulation (CI) over structural members or framing to minimize thermal bridges except at fasteners and service openings.

When planning insulation for any building or renovation project, it is crucial to consider the placement and type of insulation to minimize the impacts of thermal bridging and end up with actual performance that matches your specified R-value.

Okanagan Insulation Services | Kelowna Insulation Experts

Understanding insulation R-value and LTTR, are key to making informed decisions as a Canadian homeowner.

Partner with Okanagan Insulation Services for access to expertise, quality materials, and tailored solutions for home comfort and energy savings. Remember, when it comes to insulation, OKI has you covered!

Let's work together to make your home a haven of comfort and efficiency. Consulting with insulation experts and staying updated on industry standards can further guide you in optimizing your home's insulation performance.

Stay informed, stay efficient, and enjoy the benefits of a well-insulated home in every season.

Contact us today to learn more about how we can enhance your home's insulation performance and schedule a consultation with our experienced team!