Have you ever wondered how flat roofing insulation affects your property? Like perhaps whether it affects your home’s energy consumption levels? In essence, the kind of insulation you choose will determine how much you spend on energy bills.
However, the kind of insulation to use in a flat roof system is determined by an area’s specific building regulations and the immediate environment. This is why you should understand everything that goes into selecting the right insulation before undertaking any flat roof project. With that said, consider the following pointers:
What’s flat roofing insulation?
As you may know, authorities classify all roofs with pitches below 10° as flat roofs. In most cases, these types of roof don’t feature lofts, meaning that their insulation will be different from those in standard pitched roofs. Even so, that shouldn’t worry you because all kinds of insulation work do the same thing, helping to regulate the amount of heat entering and escaping your property. Since each kind of flat roof has its unique approach to insulation, check out how the two common types of flat roofs differ from one another:
Warm deck insulation (warm roof): Rather than getting placed in-between the decking and ceiling, this kind of insulation is installed above the roof deck. The procedure starts by laying a 100mm rigid board insulation atop the waterproof membrane. Once the insulation layer is in place, an asphalt layer is laid out on top. A warm roof insulation system is arguably the best way to insulate a flat roof considering that you won’t have to deal with any condensation problems.
Cold roof insulation (cold roof): This insulation is installed between the steel joists underneath the roofing. If anything, this is the most commonly used type of insulation. When laying the insulation material, it’s paramount to leave a 50-60mm gap between the insulation and the roofing material. It’s normal for roofers in Toronto to first take down the ceiling before installing cold roof insulation. In addition to having a cumbersome installation process, another disadvantage of this kind of insulation is that it can result in reduced ventilation, which ultimately causes condensation and moisture build-up.
What flat roof insulation solutions are available?
While there are many different materials used for flat roof insulation, here are some of the most common and how they differ:
Wood Fibre
Wood fibre is an organic board made out of cane or wood and mixed with several fillers as well as blinders. The best part about wood fibre insulation is that it offers exemplary cost-effectiveness and environmental friendliness. It also exhibits excellent natural thermal resistance, the ability to release and absorb moisture, and heat storage capacity.
Perlite
Perlite is an insulation material that forms as a result of mixing binders and organic fibres. The material also comes with air cells trapped inside it to insulate the roof. Many a time, roofers will apply an asphalt coating on this insulation material to reduce its high absorbing capacity.
Polystyrene
With polystyrene insulation, you can choose between two types- extruded and expanded. For the expanded version, polystyrene is mixed with a foaming agent, whereas with the extruded version, the polystyrene material only gets heated and expanded. The reason polystyrene is such a popular option is because it offers a light, joint-less, and durable coating that has perfect insulation properties. What’s more, this material adheres to a roofing surface easily and is an ideal base for laying out the outermost roof layer.
Polyisocyanurate
Also known as ISO, polysio, or PIR, polyisocyanurate is a foam-like thermoset plastic. This material normally gets installed between the organic and non-organic felt within your flat roof. Take note that you can make this foam material more thermal resistant by expanding it with a blowing agent.
Cellular Glass
To make cellular glass insulation, glass is crushed, heated and moulded into tapered or flat blocks. One advantage of cellular glass is that it’s naturally flame resistant. Thus, you can use it in areas with extremely hot weather without worrying that it’ll catch or spread a fire.
Not sure which type of insulation material would be ideal for your roofing project? Don’t hesitate to consult roofing or insulation professionals for advice.
How much does roofing insulation installation cost?
On most occasions, roofers will include the roofing insulation expenses in the final quote for the entire project. The price of insulating your roof may even be lower if you or the roofer decide to reuse old insulating materials that are in good enough condition. If you prefer to DIY your flat roof construction, the cost of insulation will vary depending on the chosen insulation materials. As mentioned earlier, you have a myriad of options to choose from: minerals (glass wool and rock), natural (wood wool, cellulose, hemp, cork, etc.), or synthetic materials (polyurethane, extruded or expanded polystyrene, etc).
Generally, the costs of installing insulation alone may be as follows:
- On the inside- $33 to $44 per m²
- On the outside- $76 to $126 per m²
Take note that the prices above don’t include additional costs like labour.
What’s the lifespan of insulation?
Normally, the insulation used in cold flat roofs degrades much slower than that installed in warm roofs. This is because they are positioned closer to the exterior elements. Nevertheless, all kinds of insulation materials are quite robust and can operate optimally for about 25 to 40 years. In fact, they can last as long as your building’s waterproofing materials.
Reap the benefits
Whether you’re constructing a cold flat roof or a warm one, installing insulation is extremely beneficial. For warm roofs, insulation ultimately leads to lower energy usage and consequently a reduction in the associated bills. The warm roof insulation system is excellent for kitchens, bathrooms, and all other areas with high levels of humidity. On the other hand, the cold roof insulation system offers a lower installation cost and is best suited to external outbuildings. As such, you should use it in areas that experience hot weather.
All in all, don’t forget to consult with a reliable flat roof contractor before installing any insulation. This will help you make the right decision every step of the way.
CHOOSING THE IDEAL MATERIAL FOR A FLAT ROOFhttps://coverallroofing.ca/flat-roofing-toronto/ideal-material-flat-roof/
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