How to Insulate an Attic

From the basement to the attic, ceiling insulation—a bulwark against the cold, a dwelling’s guardian—ensures the residents' comfort. A home’s insulation must be done according to the trade’s golden rules to effectively fulfill its role. What products can you rely on? How thick should it be? If there’s one thing we all want to avoid having to redo because it’s not as effective as we’d like, it’s insulation. The reason is because it’s an expensive process, but also because, in many cases, once the work is done, you no longer have access to it. Natural, synthetic, mineral, loose-fill, batt, roll, rigid, slab, or board… You have to carefully consider the materials you will use to insulate and soundproof your dwelling. Ultimately, successfully doing so depends on place-specific factors. Allow us to explain. Standard, Suspended, or Dropped Ceiling Insulation Boards Source: Canva The factors that will largely influence the chosen insulation type, without a doubt, are the ceiling type, available space, or installation method. For example, insulating a ceiling in a common area mandates a meticulous finish since an aesthetic factor is at play here. The latter must retain heat, which is where thermal insulation comes in handy and must be soundproofed from exterior noise pollution, which is where acoustic insulation is useful. In terms of materials, board-form insulation is best. Since they’re thin and rigid, they’re quick and easy to install and suit both a standard or stretch ceiling. Thin and versatile insulation boards are typically useful for a building’s thermal and acoustic insulation. However, other materials can be used depending on the ceiling’s specificities, as it happens to be with either a suspended or dropped ceiling. The insulation material is placed inside the hollow interior between the existing ceiling and the drop ceiling using gypsum, PVC, or wood panels. You can also add recessed lighting for a more finished look. Since the space beneath the ceiling is reduced, this method will typically be reserved for rooms with above-normal ceiling height. PRO TIP: The installation method is important, as well as the way you go about it, based on the material, its shape, and weight. Besides choosing the right insulation material, properly installing it will guarantee its insulation quality and efficiency. How thick should basement and garage ceiling insulation be? Source: Canva The recommended thickness you should be looking for in insulation is determined by its thermal conductivity. To benefit from effective insulation, you should also consider the area to insulate, the living space, and the area’s needs (thermal and/or phonic insulation). As such, while you can insulate a garage, crawl space, basement, or ground level, the products and techniques used won’t necessarily be the same. Also, for each and every case, you will have to determine the insulation goal, whether you’re looking to soundproof, limit heat loss, or both. The downside to insulating a basement or garage is that both these areas are susceptible to extreme cooling during cold fronts. Therefore, we recommend properly ventilating and insulating the room to limit humidity. Generally speaking, a basement ceiling is pretty straightforward to insulate. Oftentimes, it’s easily accessible, and there will typically be enough room to insert thermal insulation boards. However, if possible, avoid installing rockwool in such areas. Extruded polystyrene is best since it’s moisture-resistant. Polyurethane can also be inserted in a garage ceiling cavity. If the garage is located beneath the house, you can also insulate it from the underside (meaning through the home’s floor system) using 90-120 mm thick polystyrene or 70-100 mm thick polyurethane. Are you looking for experts for your home insulation project? Fill in our form to be connected with top-rated contractors! What’s the best soundproofing and sound-absorbing home ceiling insulation? Source: Canva From footsteps to screeching chairs to dropped items, cleaning and household appliances…there isn’t a regulation on how many decibels are deemed too many within a single household. The best way to soundproof a room remains to address the root cause of the problem, meaning insulating the area where the noise originates. You can, for example, add an underlayment beneath floating floorboards. However, it can’t always be done, nor is it always enough. There are different phonic insulation materials for ceilings: Mineral wools Natural wools Reinforced gypsum acoustic insulation To determine which acoustic insulation best suits a room, you must consider two factors: the source of the noise pollution (voices, footsteps, floor-level impacts) and the ceiling material. Installing a suspended drop ceiling with metal furring (also known as a T-bar ceiling) is a great option to limit vibrations while having enough room to insert fibre-based acoustic insulation. Vibrations are limited (as well as floor-level noises) when installing wall-to-wall metal furring. The latter makes it possible to separate the drop ceiling from the floor above it. The insulation will be placed on the T-bars and the screwed-on tiles. PRO TIP: For optimal comfort, don’t limit your insulation to your ceiling; insulate your walls too! How to Insulate a Cathedral Ceiling from the Inside Source: Canva The infamous cathedral ceiling, which became popular in the 1960s, left quite a few homes with poorly insulated, inadequately ventilated, and leaky roofs. The resulting issues are hard to ignore: astronomical heating costs, ceiling condensation, ice dams forming around the roof, non-durable roofing, partial rotting of the wood bridging or structure, etc. The solution: insulate from the inside to increase the thickness of the roofing structure to allow for minimal ventilation to prevent condensation. Consider this option if your roofing is relatively new and has decent ventilation. The existing insulation is replaced by a new material while ensuring there's about a three-inch gap between the insulation and the roof’s plywood. Then, polystyrene boards are inserted between the rafters to break up thermal bridges and create an airtight barrier to prevent air infiltration. Combining four inches of batt insulation with four inches of polystyrene lets you create insulation similar to what’s found in a new home. PRO TIP: To prevent condensation from forming under the roof, you need to have proper ventilation in place. You also have to reduce humidity transfer from within the house to the roof using a decent vapour barrier between the gypsum and the insulation. Seal the vapour barrier joints with the right adhesive tape and apply urethane above the walls and around the roof’s mechanical openings (plumbing vents or others).

Wall, door, attic, and foundation insulation, not unlike window caulking, aren’t the sole factors influencing your home’s energy efficiency. Garage doors, which are too often overlooked, allow warm air to seep out, along with a part of your savings. While heating a garage isn’t mandatory, having a well-insulated door is a non-negotiable benefit. If you’ve started inquiring about the matter, you were most likely recommended insulated garage doors. However, before moving ahead and changing your garage door, take a moment to read this article. We’ll detail how to easily and swiftly improve your garage door insulation, all that at a bargain! What type of insulation should be used for a garage door? Source: Canva Garage doors are usually insulated for the following reasons: It’s too thin It’s made with a conductive material It’s not sealed (there’s often a gap between the door and the ground) When it comes to garage doors, homeowners typically opt for thermal insulation with an R-value between R-4 and R-18. The selected insulation’s efficiency can be offset by the presence of thermal bridges, as well as the lack of weatherproofing. Have you considered simply improving your garage door insulation instead of replacing it altogether? This is often a viable option. However, for optimal efficiency, the insulation material needs to be tailored to your garage door. The choices will depend on factors such as: Regional climate Sought-after energy efficiency Types of panels and door materials Door thickness Perhaps even the opening mechanism What’s the best garage door insulation material? A simple, straightforward question, yet its answer delves into the intricate side of things. There are different types of insulation, but the two most commonly used materials are polyurethane and polystyrene. These are usually used to insulate metal or PVC garage doors. Generally speaking, they have pretty good thermal resistance. Polystyrene Polystyrene—also known as Styrofoam—is retailed in the shape of solid panels. A single, thin layer delivers elevated R-value insulation. It’s also surprisingly lightweight, which means securing it to your garage doors won’t negatively affect the opening mechanism. While it’s less expensive than polyurethane, it’s also not as efficient (R-6.6 to R-10 compared to R-12 to R-16). Polyurethane Polyurethane is made with chemical products that, once mixed together, expand in such a way that the material fully fills cavities. Polyurethane, when just as thickly applied as polystyrene, has twice its efficiency. Valentin Lamoulie, of DuraClim, mentioned that the former is also resistant to humidity, thereby making it the go-to material to insulate garage doors, provided a sufficient amount is applied. “Typically, when using polyurethane, we’ll assess the situation based on the thickness of the garage door [subject to standards, Ed.], but having at least 2-inch thick insulation is recommended,” explained Valentin Lamoulie. Garage Door-Specific Insulation Tilt-up garage door This type of garage door consists of a solitary panel that tilts up on a track due to a counterweight system. When fully open, the door sits parallel to the garage ceiling. Due to the opening mechanism, it’s best to use an insulation material that’s both lightweight and thin, while also providing optimal thermal performance. Otherwise, opening and closing the door might be more difficult since the door is made too heavy to lift, whether manually or mechanically. Sectional garage door A sectional garage door is typically motorized and consists of several hinged panels that open and close on a track. Since it’s more modern and better insulated, it doesn’t inch outside the frame like older models. An insulated garage door is really helpful to significantly reduce energy losses. When the door is opened, the panels will sit lodged beneath the ceiling. Thin insulation is preferred to ensure the hinges are hindered. Wood garage door Wood is an insulating material in itself. However, this doesn’t mean that a wood garage door doesn’t need to be insulated. Natural insulation won’t suffice, especially if the garage as a whole is heated. When it comes to a wooden garage door, rigid insulation material is the best way to go. It must be trimmed in a way to perfectly fit the doorframe reinforcement. Ideally, two layers of foam insulation should be applied. When the door doesn’t have panels, rigid insulation or a reflective foil material can be glued directly onto the door. In some cases, you may want to consider insulation kits sold in hardware stores. For others, impeccably done weatherstripping will suffice. A gasket maker should first be applied all around the door, then a weatherstrip should be installed on the door’s threshold. This solution is budget-friendly and can make a real difference. Steel garage door As for a steel garage door, it’s best to opt for flexible insulation material fitted between the door frames. Are you looking for experts for your insulation project? Fill in our form to be connected with top-rated contractors! How to Install Weatherstripping Source: Canva Door insulation won’t prevent cold air from seeping into a garage. You also have to consider the door frame. That’s where weatherstripping comes in handy, ensuring the door is properly sealed. Moreover, if water, insects, or debris seep into the garage, even when the door is shut, that’s a clear indication that the existing weatherstripping needs to be replaced. Different Types of Effective Weatherseals It’s best to choose a product that’s specific to your garage door, one that won’t hinder its opening or closing mechanism. Below are the criteria to consider when selecting effective weatherstripping: The bottom garage door weatherseal must be supple, with a U-shaped application to ensure the door is properly sealed against the concrete floor. The weatherstripping for side and top openings ideally must be designed with two or three supple fins to effectively seal the perimeter of the door. When necessary, the weatherseal placed between the door’s panels should be PVC; it’ll serve as both a draft guard and thermal barrier. Installation Tips Start at the top of the door. Secure the weather seal to the upper door jamb. Affix the lateral seals alike. Then, push the door to simulate the pressure that might occur during strong winds. Readjust the weather strip accordingly to ensure the door is properly sealed, and that, regardless of the weather conditions. If the gap is still too big, reset the door wedge. If there’s light streaming in through the door stop weatherstrip, replace the hinges with spring-loaded versions that can keep the door pressed up against the weatherstrip at all times. PRO TIP: To facilitate the installation of the weatherstrip, apply dish soap in the bottom track gaps. Then, set the weatherstrip in place, and trim any excess material. Use pliers to crimp the ends of the track to ensure the seal is securely in place. Our Top Tips for Insulating a Garage Door Underside The service life of a garage door underside weatherseal is rather limited on account that it’s compromised every time the door is shut against it. If the weatherseal isn’t airtight, humidity can seep in and cause condensation. During winter, if icicles form atop the surface, the rubber will be ripped off when the door is opened. Therefore, it’s super important to make sure that the material is airtight. Here are factors to consider when insulating the underside of your garage door. Choose a suitable threshold, made of steel or rubber, that effectively seals against cold air and wind gusts, and provides storm protection. To ensure the new weatherseal has the right dimensions, remove the existing strip and bring it with you to the hardware store (whole or in part) to measure it against other products. Measure the width of the door panel to ensure you’re purchasing a strip that fits the whole length of the door, effectively replacing the old one. To remove the existing weatherstripping without damaging it, remove the entire metal moulding that holds the rubber in place. (The screws are usually on the inside ends.) When installing the new weatherseal, first insert the T-shaped edge into the metal moulding, then slowly slide the rubber band into the threshold frame. The weatherseal moulding often makes for a snug fit, which complicates installation. Use a wooden stick or rubber mallet to gently tap it into place. Noteworthy: Climaloc products are suitable for standard garage doors and have a natural abrasive component to repel insects. Benefits of a Well-Insulated Garage Door Source: Canva A properly insulated garage door is instrumental in reducing household air conditioning and heating expenses. The temperature, as well as the humidity levels, will be easier to regulate. In fact, not only will it render using the garage a much more pleasant experience, but it will also increase the home’s overall comfort level. Whether or not you heat your garage, temperature gaps will be less significant. Without a doubt, starting your car won’t be an issue during extremely cold periods, therefore saving on engine maintenance. Having a well-insulated garage door means noise pollution will be less obvious in the home, whether the noises are coming from the garage or outside the dwelling. Lastly, since the garage accounts for a significant percentage of the home’s square footage, increasing its insulation will have an influence on the property’s resale value. Note that a door’s thermal insulation is all the more important when the walls of the garage are well-insulated since a deficiency in that regard can lead to mould growth. Garage Door Insulation: A Worthwhile Investment If you factor in that such a project—insulating and weatherstripping—can be DIYed in less than four hours, for less than $400, it’s decidedly a worthwhile investment. It’s not a very complicated task, but you can still call upon a professional to guide you in choosing the best, most suitable material.

It’s common knowledge that insulating a house will have a significant impact on the overall comfort of the ambient temperature as well as the building’s energy efficiency. While our energy expenses may set us on the right path to knowing whether our home is properly insulated or not, there’s a way more accurate way to find out, and that’s by relying on insulation standards and calculating the energy efficiency of different materials. Quebec’s Insulation Standards: A Regulation to Better Oversee Work Carried Out Source: Canva Since 2012, the Quebec Construction Code has imposed new standards for matters related to energy efficiency and ventilation. Homes that meet these requirements make it possible for homeowners to significantly save while enjoying better air quality and improved comfort. Insulation requirements have been made more stringent, especially for buildings located in colder climate zones. The overall recommended thermal resistance takes into account the combined thermal resistance of all material layers or poorly ventilated air or lack of ventilated air in a building’s wall. Note that these are minimal requirements, definitely not optimal. As part of the Novoclimat program, the requirements will be stricter for all above-grade building parts. Exterior Wall Insulation Standards The recommended value for above-grade exterior walls is R-24.5. Novoclimat’s recommended value for above-grade exterior walls is R-29. The simplest way to improve the energy efficiency of exterior walls is by installing insulation panels on the warm side of the wall. Since the work is done inside, the insulation value is increased and the walls are rendered draft-proofed, without ever touching the exterior siding. Ideally, this should be done during the renovation stage, as requirements can be met without demolishing the space and maintaining most of the original square footage. NOTE: The gaps between each panel must be meticulously sealed, and adding a vapour barrier may be needed if the chosen product doesn’t also fulfil that purpose. Attic and Roof Insulation Standards The recommended value for a roof is R-41.0 Novoclimat’s recommended value for a roof is R-51.0 In an attic, energy savings can be made by laying loose-fill insulation over the existing insulation materials. NOTE: Avoid obstructing vents or soffits located near the roof’s eaves. This could result in condensation and ice dams that could lead to material deterioration as well as impede the structure’s integrity. Foundation Insulation Standards The recommended value for foundation walls is R-17.0 The recommended value for basement floors is R-5.0 The recommended value for basement slabs is R-7.5 To improve a basement’s energy efficiency, insulating from the inside is also simpler. Rigid panels will be installed up against the concrete walls or batt insulation will be inserted between the structure’s studs held against the foundation walls. NOTE: Fibreglass insulation should never come into contact with concrete! The best product to insulate rim joists and a concrete foundation (basement or crawl space walls) is often a spray-applied polyurethane foam. This type of insulation must be covered by a gypsum panel post-application. A few exceptions or clarifications: A foundation wall that cloisters a heated space from a non-heated space, from outdoor air, or adjacent ground must have an overall thermal resistance of R-17.0, no matter where the building is located. A foundation wall with more than 50% surface exposure to outdoor air, as well as a part of a wood foundation wall, must have a total thermal resistance (RSIt) equal to that required for above-grade walls (R-24.5). A wood foundation wall must be insulated just like an above-grade wall would be, no matter the surface area exposed to outdoor air. For composite foundation walls, the percentage of surface space exposed to outdoor air has to be calculated for all parts of a wall, and the RSIt value will apply solely to that specific part. Are you looking for experts for your insulation-related project? Fill in our form to be connected with top-rated contractors! What’s the best R-value to properly insulate a home? Source: Canva An R-value—or its metric equivalent: RSI value—is a material’s thermal resistance coefficient. The higher the R-value, the more effectively a specific material will be able to impede heat flow, which is what defines thermal resistance. When referring to insulation, we often tend to forget that the total R-value accounts for the whole of the materials present in the building’s composition, rather than solely the ones considered in the “insulation” material category. Most building materials like wood, concrete, exterior siding and cladding, plaster, etc., have a significant impact on thermal performance, no matter how small it might be. When considering a house as a whole, it’s currently recommended to opt for an 80 Energuide rating with air barrier certification. Using the current building methods (concrete walls poured into an insulated form, spray polyurethane foam, etc.) makes reaching an 84 Energuide rating possible, 90 even, while also ensuring a permanent air barrier. What’s the R-value of insulation materials? When it comes to insulation, the chosen material is key. While almost all insulation materials can be put to the test in new constructions—as long as it was planned ahead of time—with residential renovations, the four most commonly used insulation types are loose-fill, batt, rigid panels, and spray foam. Here’s a list of thermal resistance coefficients for various insulation materials: Insulation materials Thermal resistance value Fibreglass or mineral wool R-3.5 Rockwool R-4.0 Extruded polystyrene (type 2-3-4) R-5.0 Expanded polystyrene (type 2) ≈ R-4 Polyurethane (type 1) ≈ R-5.2 per inch Polyurethane (type 2) ≈ R-6 per inch Polyisocyanurate (PIR) ≈ R-6 per inch Cellulose insulation ≈ R-3.5 per inch Blow-in fibreglass ≈ R-3 per inch Straw ≈ R-35 per bale Cotton ≈ R-3.8 Wood fibre ≈ R-3.3 Spray polyurethane foam ≈ R-6 Half-inch HD fibreboard ≈ R-1.5 7/16 inch OSB panel ≈ R-0.7 Gypsum ≈ R-0.44 Ensuring the Thermal Efficiency of a Building Source: Canva In Quebec, the thermal resistance standards to meet, when it comes to a new building or extending an existing structure, obviously differ. In most municipalities, these values add up to R-41 for roofs, R-24.5 for above-grade walls, and R-17 for foundation walls. Although we previously stated the recommended energy efficiency, a regular house will typically have an R-value ranging between 30 and 50. (For new homes, this number will increase to R-60.) During a renovation process, reaching such targets is often very challenging—maybe even impossible. However, homeowners should still aim for these figures, especially if their heating expenses are rather high. Quebec’s Insulation Standards: Ensuring Sustainable and Comfortable Buildings Quebec’s insulation standards, as stipulated by the Construction Code, play a vital role in building sustainable, comfortable, energy-efficient structures. These ensure buildings that: Resist Quebec’s harsh weather conditions Minimize energy loss And provide pleasant indoor environments These standards result from careful consideration with the goal of improving the quality of life for citizens while also contributing to limiting the carbon footprint. As such, by adhering to current standards, we’re not only fulfilling legal construction requirements but we’re also making a tangible step toward a future built on preserving the environment.

A garage ceiling can be insulated using several types of insulation materials. If you’re having a hard time wrapping your head around which ones, rest assured, you’ve come to the right place. In this article, we compared 14 different materials based on their thermal characteristics. So not only will you find the most insulating materials, but you’ll also find those that are most compatible with the insulation method that you may want to carry out at home. How to Choose the Best Insulation Material for a Garage Ceiling Source: Canva To figure out which insulation materials are best for a garage ceiling, we looked at 14 different materials based on the following 5 thermal characteristics: Thermal conductivity (K-value) Thermal resistance (R-value) Diffusivity Effusivity Thermal lag (in hours) Before we get ahead of ourselves, here’s a list of the best garage insulation materials: Rank Material 1 Polyurethane (latest technology) 2 Extruded polystyrene (common) 3 Expanded polystyrene (common) 4 Cork (natural) 5 Rockwool (loose-fill) 6 Polyurethane (common) 7 Expanded polystyrene (high-density) 8 Expanded cork 9 Rockwool (medium-density) 10 Expanded cork (loose-fill) 11 Extruded polystyrene (XPS HFC) 12 Extruded polystyrene (XPS) 13 Expanded polystyrene (medium-density) 14 Rockwool (low-density) Now, let’s take a closer look at the different insulation material values: R-Value (for an 8-inch thickness) An R-value stands for a material’s thermal resistance coefficient and is based on two factors: Thickness Thermal conductivity A material’s thermal conductivity is quantified by a numerical value, and the lower that value is, the better the material’s insulation properties are. However, thermal resistance, measured by the R-value is quite the opposite: the higher the R-value, the better the insulation performance. Rank Insulation material Conductivity R-value 1 Polyurethane (latest technology) 0.025 8.05 2 Extruded polystyrene (common) 0.031 6.5 3 Expanded polystyrene (common) 0.035 5.7 4 Polyurethane (common) 0.035 5.7 5 Expanded polystyrene (high-density) 0.040 5 6 Expanded cork (loose-fill) 0.040 5 7 Cork (natural) 0.040 5 8 Extruded polystyrene (XPS HFC) 0.040 5 9 Extruded polystyrene (XPS) 0.042 4.8 10 Rockwool (medium-density) 0.044 4.55 11 Rockwool (low-density) 0.050 4 12 Expanded polystyrene (medium-density) 0.052 3.8 13 Rockwool (loose-fill) 0.060 3.3 14 Expanded cork 0.090 2.2 Are you looking for experts for your insulation project? Fill in our form to be connected with top-rated contractors! Thermal Diffusivity and Effusivity Thermal diffusivity and effusivity are significant thermal properties to consider when choosing an insulation material meant for a garage ceiling. By selecting a material with decent thermal properties, you’re in turn ensuring that your garage is efficiently insulation and safeguarded. Thermal diffusivity Thermal diffusivity is a material’s capacity to transmit heat through conduction. An excellent thermal diffusivity is typically indicated by a value below 0.2, whereas a value exceeding 1 is considered exceptionally poor. Rank Insulation Material Diffusivity 1 Expanded cork 0.16 2 Cork (natural) 0.17 3 Expanded cork (loose-fill) 0.27 4 Extruded polystyrene (common) 0.63 5 Polyurethane (latest technology) 0.64 6 Rockwool (medium-density) 0.61 7 Polyurethane (common) 0.71 8 Extruded polystyrene (XPS) 0.83 9 Extruded polystyrene (XPS HFC) 0.86 10 Expanded polystyrene (high-density) 0.97 11 Expanded polystyrene (common) 1.20 12 Rockwool (loose-fill) 1.46 13 Rockwool (low-density) 2.20 14 Expanded polystyrene (medium-density) 2.99 Thermal effusivity As for thermal effusivity, it indicates a material’s ability to transmit heat through radiation. The lower the effusivity coefficient, the better the insulation material is. As such, a value above 1,000 suggests poor insulation capabilities in a material, while a value below 35 indicates excellent insulation properties. Rank Insulation material Effusivity 1 Expanded polystyrene (medium-density) 30.08 2 Expanded polystyrene (high-density) 30.60 3 Expanded polystyrene (common) 31.86 4 Polyurethane (latest technology) 32.49 5 Rockwool (low-density) 33.66 6 Extruded polystyrene (common) 38.97 7 Polyurethane (common) 41.41 8 Extruded polystyrene (XPS HFC) 43.08 9 Extruded polystyrene (XPS) 46.17 10 Rockwool (loose-fill) 49.72 11 Rockwool (medium-density) 56.32 12 Expanded cork (loose-fill) 76.94 13 Cork (natural) 96.18 14 Expanded cork 227.68 Thermal Lag Thermal lag refers to the time period (delay) during which an insulation material can inhibit heat transfer. Rank Insulation material Thermal lag (hr) 1 Expanded cork 16 2 Cork (natural) 15 3 Expanded cork (loose-fill) 12 4 Rockwool (medium-density) 8 5 Extruded polystyrene (common) 8 6 Polyurethane (latest technology) 8 7 Polyurethane (common) 7 8 Extruded polystyrene (XPS) 7 9 Extruded polystyrene (XPS HFC) 7 10 Expanded polystyrene (high-density) 6 11 Expanded polystyrene (common) 6 12 Rockwool (loose-fill) 5 13 Rockwool (low-density) 4 14 Expanded polystyrene (medium-density) 3 What are the best materials to insulate a garage ceiling? Source: Canva Polyurethane made from the latest technology and extruded polystyrene are, without a doubt, the best materials to insulate a garage ceiling. However, if you’re looking to solely use eco-friendly materials in your home, cork is your best bet. Learn more about the best garage ceiling insulation materials down below. Polyurethane panel or polystyrene panel? It all depends on the quality of the polyurethane material. If you come across polyurethane with a thermal conductivity of 0.026 rather than 0.035, it indicates that it’s a cutting-edge polyurethane technology; it’s more efficient than a polystyrene panel. Otherwise, polystyrene will be a way better insulation material. Moreso because you can choose extruded polystyrene, or even better yet, expanded polystyrene. Polystyrene and polyurethane panels have the added bonus of being aesthetically pleasing, while also cutting back on drywall use. Rockwool Mineral wools are far from the most efficient insulation, but they do have one significant advantage: their flexibility. It isn’t uncommon to see piping snaking through a garage ceiling. Therefore, rockwool is the perfect material. Since it’s very malleable, it can easily be slipped between pipes. As a result, you won’t need to install drop ceiling tiles to properly insulate your garage, which turns into significant space gain. Vapour barrier A vapour barrier is a must if your garage happens to be below a living space. Typically, the vapour barrier will be a part of the living space's flooring insulation system. Cork As we’ve already mentioned in the first part of the article: cork is an excellent insulation material for green homes. It ranks just below polyurethane and polystyrene. However, cork has two issues: Requires installing drop ceiling tiles Isn’t made for winter Therefore, if your garage ceiling is rather low, cork may not be the best insulation material. Generally speaking, in Quebec, where winters are quite harsh, cork doesn’t typically hold its own. As a matter of fact, while it does have an exceptional thermal lag in terms of heat, its thermal conductivity and resistance (R-value) are deemed average. How to DIY a Garage Ceiling Insulation Source: Canva There are three methods used to install insulation material on a garage ceiling: Glue/screws Drop ceiling (drop tiles or self-supporting membrane) Spray You can base your decision on: Your preferred method The height of your garage The insulation material you’ve selected For example, should you decide to opt for a spray-in method, polyurethane is your only option. Whereas, with a drop ceiling, you can use mineral wools, polystyrene, or polyurethane. However, using the glue/screw method, for which the polystyrene panels are typically preferred, you’ll lose a significant amount of height in your garage. Concrete Garage Ceiling Insulation Tips Source: Canva Favour the following three insulation materials: Polyurethane insulation panels Extruded polystyrene insulation panels Cork If you’re not comfortable using the glue/screw installation method, note that a concrete garage ceiling can be insulated using spray polyurethane foam.

Ensuring that your flat roof is adequately insulated is a vital part of maintaining a comfortable temperature inside your home. Depending on your budget, you can insulate your roof from the inside or outside. However, to meet Novoclimat’s program requirements, you have to select the appropriate materials and correctly carry out their installation. Discover our advice for maintaining effective insulation and saving on your monthly energy expenses. Insulating Different Types of Flat Roofs Source: Canva Insulating a flat concrete roof Pouring a concrete slab onto a flat roof means benefiting from two concrete-specific characteristics: Waterproofing Diffusion resistance These qualities render the use of a waterproofing layer, like a vapour barrier, useful. However, it very much relies on whether the concrete was properly poured, meaning without any apparent cracks forming, and ensuring that the joints are adequately coated and sealed. And it doesn’t end here, as a flat roof’s concrete slab must be highly resistant to water infiltration. Should it be insulated over or under the slab? Flat roof insulation can either be laid above or under the concrete slab. When it’s laid above it, the roof itself is similar to an inverted flat roofing system. When the insulation material is laid under the concrete slab, a layer of gravel, or greenery, is added to protect the concrete from excessive temperature variations. However, when the insulation is placed beneath the concrete slab, long-term, humidity can seep in between the slab and the layer of insulation. Therefore, it’s best to also add a smart vapour barrier. The latter diffuses humidity one way while blocking it in the other. Traditional vapour barriers have limited potential to dry ambient air. As such, the moisture trapped between the layers can lead to mould growth issues. For this reason, insulating from the outside (warm roof insulation) is often preferred when working with concrete flat roofs. Insulating a timber flat roof Timber flat roof insulation can just as well be laid under or above the waterproofing layer. However, just like with concrete, it’s advised to lay the insulation material above the waterproofing layer. Otherwise, humidity-related issues can quickly arise. In fact, the matter of installing a ventilation system is often questioned and will be reiterated in further detail in the cold flat roofing system section of the article. In some countries, like England, timber flat roofs are vented. However, studies have shown that ventilating such roofs generates more humidity compared to non-ventilated roofs. This is actually the subject of a Danish study that questions the dew point. The dew point occurs when the temperature reaches the degree at which water vapour condenses and forms small droplets. The Danes have shown that a ventilated flat roof that was insulated from the inside presents humidity issues as soon as the dew point temperature rises above 11°C (52°F). Moreover, a dew point of 11°C occurs when the temperature inside a home reaches 20°C (68°F), while the relative humidity level (RH) hits 56%. Therefore, it’s best to lay the insulation material above the vapour barrier. Should you decide to add insulation above and under the vapour barrier, make sure the insulation laid beneath the vapour barrier isn’t thicker than a third of the roof’s overall thermal resistance. How to Insulate a Flat Roof for a Warm Roofing System With a warm roofing system, the insulation is installed from the outside, thereby creating a shared thermal boundary between the roof and the inside of the home. To do so, a vapour barrier is placed directly on the roof’s structure, effectively serving as the waterproofing layer. Above the vapour barrier, a layer of insulation is added, which can be made of: Rockwool Glass wool Lastly, an elastomeric or thermoplastic olefin membrane is stacked on as a top coat. Since the insulation is stuck to the vapour barrier, it further protects the structure against water infiltration and debris. Also, by having both insulation and a vapour barrier, thermal storage becomes a possibility. Therefore, heat is stored throughout the day, and later released at night, which limits the need for heating during winter. How to Insulate a Flat Roof for a Cold Roofing System A cold roof, often referred to as a vented roof, is designed as a two-part structure that enables air to circulate between the insulation layer on one side and the waterproofing layer on the other. This roofing system’s goal is to mitigate humidity buildup through effective ventilation. The one drawback with this type of ventilation is that it can lead to humidity seepage in two ways: Snow infiltration Moisture buildup inside the enclosed space The second point is especially recurrent as condensation occurs as soon as: The temperature in an area dips below the dew point The temperature outside changes suddenly To add to this, this type of roofing is expensive, which is why it isn’t commonly used. This is all the more true in Quebec, where inclement weather often contributes to mould growth with this kind of roof. Are you looking for experts for your insulation project? Fill in our form to be connected with top-rated contractors! How to Insulate a Flat Roof from the Inside or Outside Source: Canva Whether it be installed from the inside or outside, the first thing you need to ask yourself is, “Where should the insulation be installed?” In this specialized trade, three configurations should be considered, depending on where the flat roof’s waterproofing layer is positioned: Insulation beneath the waterproofing layer (cold roof) Insulation atop the waterproofing layer (inverted) Insulation around the waterproofing layer 1. Insulating under the waterproofing layer This is the most common configuration for flat roof insulation. The layers are stacked, bottom first, like so: Load-bearing structure Insulation Waterproofing There’s an alternative with timber flat roofs. With such a roofing system, the insulation is placed directly between the trusses. The insulation and structure make a single layer. This type of insulation method meant for flat roofs is especially used with cold roofing systems, which we’ll discuss further in this article. 2. Laying insulation above the waterproofing membrane Using this method, also referred to as “inverted roof insulation,” the waterproofing layer sits beneath the insulation. It thus protects the waterproofing layer from any weather-related damages. However, since the waterproofing doesn’t protect the insulation, the latter is subject to humidity and mould. Hence, an inverted roof insulation system must have the following three characteristics: Withstand diffusion Waterproof Be frost-free The only insulation material that has all three of these characteristics is extruded polystyrene (XPS). This material is sold in panel form, which is later laid on the roofing, and covered with a layer of gravel or timber. This type of flat roof is highly sought-after during renovation projects. It means the insulation-related work can be carried out without having the replace the existing insulation. This is known as a hybrid roofing insulation system. Nonetheless, it still has three major drawbacks: The weight of the panels can weaken the structure Heat loss can occur via the roof’s edges Water can seep beneath the insulation The water that seeps between insulation panel gaps will eventually reach the insulation layer. Rainfall, which is often described as cold water, will reduce the home’s thermal performance. 3. Adding insulation around the waterproofing This technique is made possible with two layers of insulation: one above the waterproofing and one beneath it. It includes the first technique mentioned, the one used for inverted flat roofs. This type of layering limits heat loss during periods of rainfall. However, the same constraints, in terms of the roofing finish that apply to inverted roofs, also apply here. Since the waterproofing membrane is laid atop the first insulation layer instead of the structure itself, thermal amplitude can increase the flat roof’s mechanical constraints. This is especially true when it comes to edges and joints. Meeting Effective Insulation Standards by Choosing the Right Material Source: Canva Since the end of 2012, Part 11 of the Quebec Construction Code and Novoclimat program have mandated a minimum R-41 rating for all flat roofs. However, this regulation solely applies to new constructions. To reach this value, you can turn to the following insulation materials: Polyurethane or urethane Glass wool (fibreglass) Polyurethane or urethane “Polyurethane” and “urethane,” are terms used interchangeably. They both refer to the same insulation material. Urethane insulation is a worthwhile insulation for flat roofs. They’re sold in either foam or panel format and are especially efficient materials for insulation, soundproofing, as well as waterproofing. Polyurethane has an R-value, per inch thick, that’s between 5 and 7. Glass wool Glass wool is one of the most commonly used insulation materials for flat roofs. Albeit fibreglass isn’t as efficient as polyurethane, it’s still a pretty decent insulation material. It has an R-value, per inch thick, that’s between 2.2 and 2.7. Glass wool is a mineral wool made with sand and recycled glass. It’s a great thermal and phonic insulation material that’s also especially resistant to humidity. It’s super easy to install and doesn’t require any sort of regular maintenance. What about EPDM (Ethylene Propylene Diene Terpolymer)? EPDM’s R-value is somewhere between 0.24 and 0.33, however, it isn’t an insulation material per se. The truth of the matter is that this elastomer assembly is actually a single-layer membrane that serves as roofing for flat roofs. As such, you won’t want to insulate your flat roof with an EPDM membrane. How thick should a flat roof insulation be? However thick the insulation layer should be truly depends on the flat roof’s structure and intended purpose. For thermal insulation, the recommended thicknesses are between 10 and 15 cm, based on the insulation type selected. Regardless, to reach the required R-41 rating, you’ll have to take into account the chosen material’s R-value. As such, given the above-listed properties, fibreglass insulation should be thicker than one made of polyurethane. Insulating Your Flat Roof: A Sustainable Investment for Unparalleled Comfort The insulation stage is crucial to improve a building’s energy efficiency while also benefiting from unparalleled comfort. By choosing the right materials, you can significantly reduce heat losses during wintertime and maintain a comfortable temperature during summertime. By investing in quality insulation, you’re also reducing your long-term energy expenses and carbon footprint. Insulating your flat roof means ensuring your indoor space is comfortable and eco-friendly.