What are the Benefits of Earthwool Insulation?
Earthwool can produce upwards of 8-10 degrees difference - Here is why:
Earthwool insulation helps to maintain a uniform temperature, which means the efficiency will improve enough to keep each room closer to the same temperature with far less energy consumption to do it.
Insulation helps heating & cooling machinery work more efficiently, which means you’ll set thermostats to a less extreme temperature setting to achieve the same results, and it will take less time to get there, and maintain it for longer once power is off. This equates to lower watt, lower fan, less gas used, less often. You can expect this difference to be significant.
Insulation is scientifically guaranteed to perform when installed correctly using quality materials, and strategies suitable to counter thermal negatives found as a result of poor building codes (see Double Layer section below).
Adds value to all residential, commercial and industrial structures.
Reduces structural vibration and buffers soundwaves, which means your less likely to be bothered by planes, trains, traffic, trades, neighbours or otherwise. It traps sound within the home to a noticeable degree of change, which offers far better privacy in a country where homes are built far too close for comfort or convenience.
Insulates water pipes; when Double Layer options are purchased (See below).
Improves sleep; insulation regulates temperature so your body doesn’t have to work as hard to keep you comfortable throughout the night. This means you get far deeper sleep and more of it, and your body receives a better charge along the way. Sleep is vital to a healthy happy life.
Improves health & breathing; roof cavities are vacuumed prior to installing new materials, so the removal of harmful dust drastically improves air quality and reduces asthma symptoms and similar issues also experience positive improvement.
Reduces aches and pains; in elderly and in those with varying injuries and/or conditions there is almost always noticeable improvements to comfort.
Reduces greatly the chances of heat-stroke &/or deaths during heat-waves.
Keeps your pets comfortable & reduces the noise barking inside the house makes to passer-bys’s and neighbours.
Reduces greatly the cost of working comfortably from home.
Creates the feel of a brand new home for a fraction the cost of most kitchen & bathroom renovations.
Will save you upwards of 40% - 80% on energy cost, when done correctly, top to bottom, and even greater can be achieved taking added steps to create what is known as a “passive-home”, meaning no more air & moisture leaks, proper ventilation and other steps that contribute to overall efficiency & longevity.
IMPROVED MENTAL HEALTH; for all of the aforementioned. It’s really hard not to start a life of positivity when your home & your life within it starts working for you rather than continuing to work against you.
DEEP REGRET; our primary feedback is the amount of money our clients would have saved if they’d have just done this when they bought their homes. Most people receive their first year worth of quarterly bills following installation, and then start researching the weather to draw comparisons in usage. Most people are forced to revisit their initial renovation-budgets that were taken out with their mortgages once they’ve realised their mistake in prioritising aesthetics over function.
The amount of energy you conserve will depend on several factors including the size, layout, position, and construction methods used to build your homes &/or structures; the living habits of individuals &/or employees &/or machinery and equipment in operation, the type and efficiency of the heating and cooling systems being used, materials used in construction and the type of energy/fuel you use to cool or heat your home/structure.
Once the energy savings have paid for the installation cost, because they most certainly will, energy conserved is money saved for decades. This is especially important when you understand energy costs will continue to rise the more the transition away from fossil fuels accelerates. For those of you not paying for heating and cooling your ability to regulate temperature will become much easier, as R4.0 Earthwool insulation in the ceiling can produce a temperature difference upwards and exceeding 10 degrees, so no reason not to do it. However, the bulk of people do pay for heating and cooling, so we’re strictly talking about them when we say “savings” and “pays for itself”. Insulation investments should pay themselves off and start saving you money in no more than 5 years.
How Earthwool Insulation Batts Work
The insulation products we use most are Glasswool "batts", specifically the Earthwool brand made by Knauf, so that is the product we'll be talking about. We do use other products for commercial & industrial applications, however we’ll speak mostly of batts because they make up the bulk of insulation sales in Australia, and this education is primarily aimed at you the home owner.
Earthwool Batts are nothing more than fine glass fibres layered into what essentially looks like a big soft sponge or "batt", and these batts are made up of millions and millions of these fibres, which are layered over and over until adequate thickness allows for the desired "R-Value" for each product. These many layers containing millions of fibres create billions of air-pockets, which help to reduce energy transfer from one space to another. The air captured within the batts is an effective insulator because stagnating the air causes it to lose most of it’s convection. The batt also offers low conduction, which means the batt itself won’t transfer energy easily when touched by other materials. In extreme environments such as an Australian roof in summer, the air molecules expand to create positive air pressure within the roof which forces air through the batt at an increased rate creating a convection loop within the batt’s air pockets, which cools the air within the batt. The type of material is also a factor, as some materials themselves absorb heat faster than others, and/or have varying degrees of density of both the material itself as well as the fibre-count.
Insulation works exactly the same in winter as it does in summer, the only difference is that in winter you need more insulation to match the performance in summer months because the colder the air the more easily it’s energy can radiate. The reason for this is that cold air molecules are smaller than hot air molecules. Cold compresses, heat expands… this is Physics 101, so colder air radiates far more easily than hot air will because the molecules shrink to fit through cracks easier. This is why those of you with homes raised on piers can literally feel the draft coming through the floor in winter whereas in summer you cannot.
Why Earthwool Batts For Walls/Ceilings?
NO Formaldehyde (No carcinogenic off-gassing).
Formaldehyde in products is banned throughout most of the world.
NO Phenol Binders (Soft & itch-free).
NO Colour Dyes (No need for the aforementioned).
Glasswool material resists energy changes/transfer greater than Fibreglass and polyester.
Thinner Fibres = Higher Fibre Density = More Air Pockets = Greater Performance.
More Tensile Strength / Durability
Far Greater Resistance to Extreme Heat.
Far Greater Resistance to Moisture.
50 Years Manufacturer’s Warrantee.
Why Polymax Polyester Batts/Rolls For Underfloor Insulation?
Does NOT Degrade in Atmospheric Moisture/outdoors. Material Wicks Moisture/Condensation To Protect Flooring.
Does NOT Require Water Vapour Barrier.
Does NOT Require Strapping.
Batts Are 11m Rolls = Far Fewer Gaps.
Can Be Installed/Retrofitted As Low As 400mm.
70 Years Manufacturer’s Warrantee.
How Important Is Insulation In Warm Climates?
Cold air radiates more, and that is the sole reason warm regions of the world think they can get away with ignoring the science behind the construction process and do everything they can to cut costs by de-prioritising key steps within the building process. It’s not that builders are doing anything wrong, they’re just following code. Australia’s buildings codes set the bar low, inspectors can be bought and the market doesn’t know enough to know how to do better let alone avoid the issues these ‘codes’ create for them in the first place. Thankfully with new government, we’re seeing a shift in attitude, new industry certification and a level of oversight that will end the “She’ll be right mate” Tradie culture. Anyone from European nations, Russia or North America knows Australian homes are but a shell of what a house is meant to be, and all that is changing now.
Yes, colder air creates greater need for insulation, but insulation in the north is useless without air-sealing & ventilating the structure. It’s not just the insulation that makes the difference, as the environment the insulation is installed within will also determine the performance of the insulation and with that the entire structure and its sustainability infrastructure.
However, warmer climates carry more moisture in the atmosphere. It may not be cold, but it sure as hell isn’t dry on Australia’s coast either, and water is the world’s most corrosive compound. Moisture Damage, not a single home in Australia doesn’t eventually fall victim to it. Whether it be roof trusses warping the shape of the entire roof/walls, floor boards pulling themselves apart, mould rotting the home from within, foundational cracks, uneven floors/walls and the like; this is all caused by moisture being carried into your home along with that very same air your builder neglected to seal off with simple caulking glues. Not exactly an expensive or timely step in the building process either, so why aren’t things being glued &/or sealed?
1) They’re not being taught to air-seal, nor are they taught how and/or why this is so vital to any build’s comfort and structural longevity.
2) Until NCC-22 was released, nobody has been required to do so under the building codes of Australia, so they don’t. Simple as that.
Irrespective of climate or the standard of build, it is always a poor decision not to insulate anything that can be insulated. Every inch of your home’s sustainability is more efficient with insulation, and every inch of your insulation is more efficient when you can’t see sunlight or feel moisture inside the roof; among other things.
What Is Air-Sealing & How Important Is It?
Air-sealing is the act of ensuring no air can enter or leave the structure at will. The product used most to achieve this goal is caulking. Caulking is used to fill tiny gaps found where wood touches wood, where wood meets concrete, where windows meet wall studs and essentially anywhere that air can and will penetrate the structure. Air carries moisture, and moisture can and will degrade your homes DECADES faster than they would without exposure.
This step is meant to be taken BEFORE the structure receives insulation, as it is being wrapped in plywood & sarking/builder’s plastic or other water vapour barrier or foam boarding/cladding. Insulation batts do not work nearly as well in an environment that doesn’t offer stagnation of air within a dry space, so if you do not air-seal then air flows through the wall, into the wood, into the batt, creates a convection loop within the batt and eventually the energy is transferred into or out of the home. All of that air carries moisture that has now penetrated your home’s materials and has begun to degrade the batts & everything else not waterproof. Most of the wood preservatives evaporate in temperatures lower than Australian roofs can reach. Add considerable changes in temperature, especially during seasonal change, and the wood expands and contracts… pulling your home apart from the inside out. The more this process gains momentum the faster this process will progress.
Air-sealing the structure stops all of the aforementioned dead in it’s tracks, and accounts for 50% of your home’s thermal properties/performance/longevity, and that’s before you insulate. Without an air-seal your insulation batts will only work 50% as well as they should, and the proof is in the pudding when we see that almost all homes in Australia have more problems after 20 years than houses in other countries that have stood for HUNDREDS of years!! Those homes were air-sealed/weatherproofed, and yours was not, that’s basically it.
Air-sealing is achieved from tapes, glues, caulking, certain thermal wraps, builders plastic, expandable foams, rubber inserts/linings, etc. Each build offers its own challenges, and there’s numerous products and strategies available. Ventilation and moisture regulation is also a big part of this process because you cannot trap ait within the home at all or it will cause issues, mould being the primary concern.
When you’ve created an air-tight well-ventilated home, and your structure passes what is called a “blower-door test”, and moisture is regulated… then and only then do you own what is known as a “Passive Home”. This level of structural integrity and efficiency is part of the new NCC 22, which aims to raise the Australian standard of homes to be more consistent with the rest of the modern world. This effort is the only solution to reductions in energy usage inside Australian homes because “passive” structures improve thermal efficiency of insulation by 50%. Whenever extreme heat, moisture and light is 100% incapable of touching your insulation, it extends its life into the 100+ year range.
How Do I Know If I Need Insulation?
If your home or structure cannot maintain its temperature for extended periods of time without artificial heating and/or cooling... your structure has terrible thermal properties and you need insulation. Period.
Meaning: if you turn your Air-Con &/or heating on and its set to an AUTO temperature setting, but the machine almost never cuts off and/or never stays off for long before turning itself back on then you need insulation. If you have to set your machines many degrees beyond the desired result simply to get close to the desired temperature, you need insulation. Don’t assume a fireplace negates the need for insulation either, because with better thermal properties you can quickly overheat the home and find that your wood-stack should be lasting years, not months or weeks.
You wouldn't go out in a blizzard naked, no, you'd wear warm clothing; clothing is insulation. Your home is no different, it too needs insulation to stay warm in winter. However, unlike our bodies in summer, the more insulation in a house or structure, the cooler it will stay in summer. Insulation will work to your benefit all year round no matter what the weather has in store for us, so you always need good insulation.
Will I Feel A Difference?
You won’t believe you’re even in the same house. You will absolutely feel an enormous difference.
Insulation is everywhere. Nearly all life on Earth has adapted to account for their own thermal properties as well as the environments they live in season to season. You've surely learned about blubber and fat storage, about burrows and nests and countless other methods being used in nature to stay warm in winter. You’ve also likely been exposed to some clever adaptations for keeping cool in summer, such as Kangaroos using saliva to cool themselves through evaporation, humans and our sweat glands, birds spreading wings and you’ve may even come across artificial means through innovation if you look hard enough.
Jumping Jack Ants in Australia create a dense covering of white sand and other light coloured materials around their mounds to reflect sunlight in summer, and then in winter they replace that reflective ring with darker matter to keep the colony warm throughout winter. The sun’s heat is either absorbed into or reflected away from the mound simply by ensuring the right coloured surface.
Insulation is a part of nature everywhere you look, so it should be common sense to factor insulation and to prioritise it as heavily as the foundations and framing of any structure. The more considerations that are met in your planning the better the result and yes, every improvement helps, even if it’s so small you need NASA to measure it. Sometimes all it takes a fraction of a degree to impact how you regulate body temperature at night, so every factor is to be prioritised.
Every point of a degree is invaluable to all life on earth. Every point of a degree attributes to the end result, and once more we ask you to imagine yourself naked in a blizzard so cold you can’t move. Would you notice the difference a mere T-shirt would make? You’re still freezing, sure, but if I asked for the t-shirt back would you want to keep it or be naked again? Now imagine that material covers every inch of your body with no gaps. Would you notice that enough to accept that any amount of any insulation is infinitely greater than none at all? or would you allow your scepticism of the result to dissuade you from being naked? The Insulation we’ll install can and will provide temperature differences as high as 8-10 degrees, which is insane value for money.
A t-shirt isn’t designed to keep you warm. Earthwool is. There are countless examples in nature, but often we see extraordinarily impressive results being achieved artificially through intelligent means. Innovation. Earthwool is the Rolls Royce of insulation Batts globally. You will absolutely notice, so will your bank accounts.
But, I Only Want To Insulate Here/There…
Once more we ask you to imagine yourself naked in a blizzard. We will offer you the same full body covering as thin as a t-shirt, only this time we were asked not to include long sleeves and leggings. Most of you tell us its because of the carpet, but in this example your request that we provide partial coverage is because you have hair on your arms and legs, therefore you “don’t need to insulate them”. Whether it be a hot roof heating a garage and then the wall to the bedroom, or the neighbouring carpet area in winter affecting the newly insulated areas. Either way, radiant transfer of cold/heat will occur, and your entire home is negatively affected by it.
We’re often told “this room isn’t cold/hot”, and then we see the aircon on that wall, making you think “only the other room that doesn’t also have a heat/cold source needs doing”. Trust us, unless you have a 5mm+ thick rubber underlay then your carpet is likely laying over breathable foam or similar product, and therefore is doing next to nothing to stop thermal radiation & convection, as it is often less than 5mm thick. Your carpet is not the champion of your comfort, technology is, and that technology costs less with full coverage.
With full coverage the heater on one side of the home would reach much farther into the colder area, the entire home will be more efficient and you will use less energy and save money. We do not offer patch-work, as the final result when concerning insulation boils down to coverage, without gaps. We’re about results. We would have to partially vacuum your roofs too, which would be a redundant exercise that poses health risks to the entire home.
The reason we compare your carpet with hair, is that neither is good enough. Your feet create warmth, the carpet insulates your feet, giving you the illusion the room/floor is efficient. Ultimately the bite of the cold floor is all your carpet is protecting you from, the cold still radiates right through it, which is why your homes still get cold the moment your heaters are turned off.
So, What Is R-Value?
The “R-value” of a substance is its direct measure of its resistance to transferring energy or heat; R-Values are expressed using the metric units (m2.K/W). Basically, the higher the R-Value the better the resistance for energy transferring from one space to another.
What is 'Total R-Value'?
Total R-Value is the combined R-Value of all insulation materials as well as the materials used in the home's construction; additionally all air spaces are to be included.
What Affects Total R-Value?
In theory, everything. A home's "Total R-Value" is the total sum of all insulation products used in construction, including the various R-Values of everything on either side of the insulation products as well as the air around them. These other materials include but are not limited to wall cavities, cladding, bricks, timber studs, wall wrapping, underlay or plasterboard; each material's type and thickness helps manufacturers, builders and other authoritative bodies to calculate your home's overall level of efficiency or "Star-Rating".
In reality however, these calculations are much more complex because a range of factors will affect the Total R-Value for a particular space inside a building.
Heat radiation through non-insulated areas such as windows, especially single pane glass windows.
Heat conduction where insulation is not in contact with timber or metal frames, or areas where Thermal Bridging is occurring.
Thermal properties vs environment.
Rates of convection of each building material.
Air movement through ventilation holes/exposures/gaps in the build
Moisture entering the home through unsealed areas and open air vents and/or whirlybirds.
Degraded insulation, if any is present.
Damaged insulation or gaps that let air through and/or poor workmanship.
Skipping areas such as attached garage spaces, overhangs and drop-down areas as well as all of those fabled "hard to reach areas".
Sun Exposure / Positioning / Environment.
If you consider each of the many variables with competing brands, the numerous types of insulation and construction methods, you should realise quickly there is a lot more to this insulation stuff than slapping batts in a house for the cheapest sticker price.
Seek expert advice like you would with anything else, and do as much research as you can before deciding on a plan of action. You can use product R-Value as a guide, but you should consult with an expert so none of the aforementioned fails to be considered in your planning.
What R-Value Does York Insulation Recommend for Australia?
CEILINGS
Your homes are all very different, but be assured no matter the structure if you apply a minimum standard of R4.0 for any ceiling then you will see great results. This recommendation does not account for and should not include the combined R-values of other things like sarking, roof blanket, foam panelling, plywood in fire danger areas, etc. The ceiling itself should receive R4.
However, for optimal performance in temperatures exceeding 35°C we insist there is often need for no less than R6, preferably comprised of two layers, or what we call ‘Double-Layer’ (See Double-Layer section below).
Single layer installations, or "base layer", is merely a job half done. Double layered insulation covers all of your roof's timber supports, achieving the best possible coverage and guarantees greater performance & savings. Unlike all blow-in/loose-fill products, batts will not compress, which reduces the product's performance considerably. Covering the joists eliminates most Thermal Bridging, which is detrimental to your insulation's performance. (See Thermal Bridging section below).
We recommend a minimum of R5/R6+ for any newer/"modern" and/or larger and/or more open planned homes, as well as any home with a low pitched roof. “McMansions” included, which are significantly less thermally efficient and should be done correctly in two layers. The larger the house, the larger the air volume you are trying to control temperature within. The newer the home, the more thermal deficiencies you have to counter to achieve a respectable outcome. You would think the opposite was true, but we all know “They don’t make em’ like they used to”, and houses in Australia are as much a part of this ‘throw-away’ society as the device you’re using to read this.
More air volume within the home means more wall and ceiling space, more windows and glass, more floor space (if on piers). The more surface area the more space to allow transfer of heat, and the more air volume within the structure the greater your energy usage will be to combat the laws of physics. The larger and more open the structure, the more seriously you need to take your insulation. However, the larger the roof’s air volume, the longer it will take to heat up enough to begin radiating down into the home.
Environment dictates performance, so know the consequences created by your environment before selecting products &/or R-values.
WALLS
We also recommend Only R2.5 High Density materials for any Walls. We recommend you use only High Density Wall Batts, because they’re far more thermally efficient, are more ridged and have much greater acoustic properties. When attempting to measure the extra cost vs the return, just remember every cent of your investment goes towards taking dollars away from all future energy bills, so no matter what it costs you’re getting 100% of it back and more if you do it right. The more you spend the cheaper this investment becomes, long term, which doesn’t help you if your planning is short-sighted.
UNDERFLOOR
We recommend R2.0 - R2.5 Polymax Polyester only. Higher R-Values must be achieved with ceiling batts, but are not required to achieve a great result as the underfloor does not deal with extreme temperatures below zero throughout most of Australia throughout most of the year. The batts are heavier and ticker than the 90mm floor joists, so they’re far more difficult to support against gravity and not many staples are capable of grabbing that much material and having much room left to penetrate deep into the wood to hold forever.. They require a lot of strapping and in many cases the height of the underfloor space doesn’t allow for an adequate workspace. The underfloor rolls are 11m long and are supported across foundational beams, do not require strapping and provide a more suitable fit far less likely to require ongoing maintenance, if at all.
With Insulation, more is less, and less is more…cost. The decisions you make to try to save and/or cut corners on your investment today will negatively impact your comfort and savings tomorrow.
We appreciate that not everyone has money laying around, but the fact of the matter is that if you don’t buy the best performing materials you won’t save as much and will need to replace them sooner, so cheaper materials are more expensive in the end. If you can’t afford the best right now, we recommend saving until you can.
Can Existing Walls Be Insulated?
Yes, absolutely. Depending on what you can or want to spend there’s a lot of options to be explored.
Access is the main consideration, and the type of build you’re dealing with will dictate which methods are practical. Access is important because we do not condone the use of blow-in or loose-fill products of any kind. They will all sag with gravity, and will compress to the lower half of the wall 100% of the time. Pointless investment, straight thievery, not to mention it will degrade into a toxic layer of dust. We require access for bulk insulation, or batts, which will hold their position and offer a far longer life-span. Some newer foam-cube products can avoid sagging, but they have large air-gaps compared to those between the insulation fibres not to mention the amount of holes needed to insert this product begs the question “why not just take the gyprock down and do it properly”?
Some of you will do research and find videos of installers in others countries drilling holes in the outer walls and injecting loose-fill insulation. Looks awesome, its clever and very simple to install without damage or demolition involved. However we must remind you again those homes overseas are properly built, we live in sheds exposed to the elements you cannot do those things here and expect them to work the same, especially when the home is not wrapped properly for moisture protection. In Australia you have to cut your way into the wall in most cases to see if the wall has been wrapped and/or can even house insulation without absorption being a risk long term.
Some homes can only be accessed from the interior after removing the gyprock walls, so typically during extensions &/or renovation projects this is a practical approach because the cost to hang sheets and plaster/paint is already present. If this is not a practical or affordable option for you, know that concentrating your budget solely on retrofitting the worst wall is more than worth the effort (most often westerly), because protecting even one wall can make an enormous difference to compliment the ceiling’s efforts.
What is Thermal Bridging?
A thermal bridge, also called a cold bridge or heat bridge, is an area or component of an object which has higher thermal conductivity than the surrounding materials, creating a path containing the least resistance for heat transfer. Thermal bridges result in an overall reduction in thermal efficiency, and in Australia Thermal Bridging is a huge issue because nothing is air-sealed.
e.g. Thermal Imaging often showcases where all the timber is located, highlights how much your windows aren’t helping you as well as highlights all cracks allowing easy transfer of energy. Each of those clearly visible weak-points in your home’s thermal properties is acting as a Thermal Bridge.
When you have nothing underneath tiles and less than 2 inches of roof blanket/space-blanket compressed directly underneath iron sheeting, you get a surface temperature in direct sunlight of between 50°C - 80°C on a good Australian summer’s day… that energy radiates downwards into the roof to create a cavity that is on average 40°C - 60°C in summer. Your roof cavity has no problem heating up the materials in your home, which isn’t air-sealed, so 100% of homes in Australia have thermal bridging issues.
This generally applies in a ceiling, where the thermal bridges (roof beams) offer an easy avenue for hot air radiate down into your home. Covering the roof supports with a secondary or "Top-Up" layer will almost completely negate Thermal Bridging, which will allow your insulation to perform to the height of it's capability. The larger the roof, the more roof supports, the more roof supports, the more thermal bridging is taking place; meaning the larger your home the more need for a Double Layer Installation.
Ceiling fans, ceiling roses, vents, air ducts when not in use, windows or doors… all thermal bridges.
Another common example of a thermal bridge is any unprotected floor raised on piers; unprotected meaning unsealed and/or insulated. In this instance most or all of the home's floor space is acting as a thermal bridge, especially if the floor is made of low density materials carrying high convection rates such as wood. This creates a very noticeable example of a cold bridge/cold radiation. Underfloor insulation such as R2.0 Polymax Insulation by Martini (very long batts that come in rolls = less gaps between batts) are a great solution to a cold floor. We use this product to keep our Blue Mountains clientele super toasty in winter.
To completely eliminate thermal bridging in floors, this Polyester insulation can be covered for a nice air-tight finish with insulation sheeting, blueboard or similar sheeted product to seal the insulation and create a sealed air-tight cavity. Insulation sheeting eliminates thermal bridging and adds to the thermal properties created with underfloor insulation. If the home is on a steep incline and/or is high enough to make the underfloor visible than insulation sheeting can also offer your home's underside a much better look as apposed to leaving it exposed. If skirting is not an option than insulation sheeting is an easy alternative, as leaving the home exposed to the elements alone will age it much faster. Wrapping the entire home with insulation sheeting during construction is a brilliant way to compliment your insulation batts and eliminate the majority of the home's thermal bridging and it protects the home’s materials from weathering.
Successful people always preach about getting all the little things right, the "1%ers", the little things that add up to make a world of difference to the end result. Thermal Bridging matched with Air-Sealing are arguably the two most important aspects of thermal properties within a home in Australia. Thermal Bridging is currently being ignored by the majority of our industry. Every joist, every wall stud in the home that is covered, every nook & cranny, every crack & crevasse that is sealed and/or insulated will increase the home's overall performance and give you that much more from your insulation.
We often talk about how insulation is guaranteed to pay for itself quickly via efficiency and savings, so know that the added efficiency from eliminating thermal bridging will further increase the rate at which you'll save; paying itself off that much quicker. Essentially the more you spend on quality materials and labour the faster you’ll get it all back and start saving, so cost should be weighed as heavily as your need to save; or more. Insulation literally is as safe an investment as they come; go all in on it with the right strategy with the right installer for your project.
If reducing energy consumption by up to 50% - 80% or more sounds good to you than you need to be thinking about double layered ceilings, using quality products like Earthwool and have a focus to seal and eliminate thermal bridging everywhere possible. We understand that some homes are built better than others and are located in different environmental conditions, but you’ll never fail to feel the difference felt when you factor thermal bridging into your planning. If you ignore thermal bridging, do not expect this level of savings.
What Is “Double Layer”?
Firstly, a “Double Layer” Installation is merely the act of installing a secondary layer of batts to rest over the initial layer, or base layer. The base layer rests between the ceiling joists and rests in contact with the ceiling. All wires and pipes rest over the first layer of insulation, and the second layer is laid over the pipes and wires. The secondary layer, or Double Layer is laid tight together to make a grid of batts that face perpendicular to the ceiling joists so that they’re more easily covered. Covering the joists not only adds R-Value and eliminates thermal bridging, it also covers gaps the first layer can’t fit into, it protects the first layer from extreme heat and moisture exposure and it insulates your water pipes if they happen to run through the roof cavity. A second layer greatly extends the performance and longevity of your first layer.
With a single layer of R4 you will be comfortable all year, except days above 35°C (this varies house to house), so the extra layer is insurance for heat-waves. The reason for this is your roof is an oven, and once the wood matches temperatures above 50°C, your insulation stops working because it’s being cooked from 3 sides. The wood must be covered, or don’t expect R-Values of any amount to help you during heat-waves after 11:00am. That’s about 3 weeks of the year that R4 Earthwool isn’t enough, but the moment there’s enough insulation to stop thermal bridging, you have too much insulation for the roof temperatures to affect you again within the life-span of the batts.
Earthwool comes with a 50 year manufacturers warranty, but you’d be lucky to surpass 30 with optimal performance with exposure to moisture and extreme heat. The secondary layer acts like a buffer, a shield rather, so that first layer at least has a chance of lasting the full 50 or more, and not loosing much of its full performance along the way. Without the second layer, its a 30 year investment, but still well worth every cent.
Most other countries do double layer to cover the joists to account for thermal bridging, only they don’t do it with two layers of batts. Other countries air-seal their structures so they can get away with using loose-fill insulation and not have it reduce itself to a compressed layer of super-fine highly toxic dust. However, other countries lay a layer of batts before “topping up” using loose-fill or blow-in insulation to fill gaps and add R-Value to create that desired thickness or “double layer”. They do this because they’re honest enough to admit to their clients that loose-fill products of all kinds will absolutely compress and lose R-Value within 5 or so years of blowing it in, so they simply start their process by laying proper batts that can hold their shape so the entire job isn’t reliant on gravity not existing. There roofs also don’t get nearly 50°C, so it’s beyond overkill to look cool on YouTube, but totally required in Australia.
The truth, is that Double Layer is standard practice all over the world they just don’t refer to it as such because covering the joists is common practice everywhere except here. The only time its covered typically is with loose-fill or blow-in products; and thankfully the country is waking up to the scam that is loose-fill insulation. Double layer is merely a York Insulation term created to describe common practice not common in Australia.
Why Not Buy Higher R-Values? Others Say I Don’t Need Double Layer.
We often hear clients tell us the competitor, family or friend disagrees with the need for a “double layer”, insisting on a single layer with a higher R-Value. This would be true if the joists were tall enough to properly house the outer wall of an R5 Batt, which towers over a 90mm joist.
This matters for two reasons. The first is the wood is exposed, so 10% or more of the ceiling is exposed, as wood in its natural state will easily transfer energy. In fact, once the wood matches roof temperatures above 50°C it doesn’t matter what insulation or R-Value you have it’s not going to perform in that hot of an environment, which is why every house in Australia has a magical temperature where everything stops working unless everything is turned up to full blast, and even then it’s often not nearly enough.
The second is that insulation fibres are layered horizontally, and are not designed to protect the air penetrating sideways, they are designed to protect head-on. The manufacturers instruct on all packaging to “tuck” the batts into the joists. The correct placement in all insulation instruction images shows the batts tucked into the joists, mounding upwards at the centre. If the batt towers over the joists the heat penetrates almost the entire top 2/3rd of the batt with ease, rendering your R5-R6 Batts severely handicapped from day 1. Add 50°C ceiling joists and your “R5.0” is suddenly indistinguishable from R4.0 on a thermal scan. Will R5.0 out-perform R4.0 overall throughout the year? yes, but you’re not getting true R5.0 performance / value for money, but you’re certainly paying for it.
No 90mm joist properly houses any Batt thicker than R4.0, and no Batt can or will outperform Double Layer without the wood covered. R4.0 plus R2 is greater than R6.0 on its own if there is less negative R-Value/Thermal Bridging, and this R6.0 comprising of R4.0 + R2.0 costs less than R5.0 on it’s own.
Extra materials can be whatever you feel like paying for. We’ve done Double R3.5, Double R5.0 and tonnes of Double R4.0. Some clients understand the big picture, and that picture is that when facing so many negatives you have to overachieve to make up for them. That means if you live in Australia you need to exceed the standard as a starting point, and go all-in from there depending on what you can or want to afford.
What Is The Greatest Value For Money?
Double Layer R3.5
This option provides a total ceiling resistance of R7.0 with all wood covered to eliminate thermal bridging, and it costs roughly $200 more than a Single Layer of R5.0. That’s R7.0, in two layers, for a price just over R5.0 in one layer. This is by far our most popular option, and makes you practically immune to weather.
With R7.0 you will never feel the heat above your heads ever again, heatwave or not, and the rest of the year the air-con will hardly cross your mind. In winter the only cold you will feel will come from everywhere except your ceilings, and the entirety of the 25°C or so coming from your heaters will never escape through the roof again, and will start to fill more of the home with heat as result.
How can we say this and be so confident? Once you go beyond a certain thickness of Earthwool insulation, and remove negatives by covering the timber, you further increase efficiency of resistance well beyond the ability for your roof to transfer its energy through it. Once you cover the wood and exceed R5.0 in doing so, to feel the heat in the roof, you would need a hotter roof. Double layer maximises performance well above your roofs ability to transfer enough energy for you to feel it.
Accessing The Roof Post Double-Layer Installation;
The only reason we’re ever given when clients reject recommendations for Double-Layer Installations is fear or concerns the roof will be inaccessible following the job. This is true, walking over two layers of insulation and not seeing where to step is a big issue, which is why we recommend a walking bridge be installed prior to works commencing.
A Walking Bridge is simply Yellow-tongue boarding installed over the top of the ceiling joists within the roof cavity to create a safe path of access from the manhole down the centre of your roof. These boards will create a path of easy and safe access for all future trades entering your roof, allowing easy access to lights, wires, ducting, water heaters, piping or otherwise. Once there is a safe path of access, the rest is double layered.
Without this Walking Bridge, the roof can still be accessed any time safely. All one must do is simply pick up the second layer of batts, which are laid over the joists to make a tight grid/blanket. You can simply peel batts away and create a path of access in any direction needed, but if you do not put these back in place on the way out of the roof you’re risking the home should they be covering downlight transformers or old TV antennae boxes. We always ask clients to ensure the roof is checked prior to and after the work to determine the state of the roof’s piping, ducting, wires, lights or otherwise so we can rule out entering the roof any time soon after double layer is laid.
If you care enough to choose double layer you might as well care about the safety of your roof and anyone that enters it. We advise a walking bridge be installed for all Double Layer Installations.
Is My Old Insulation A Health Risk?
In most cases… yes absolutely.
Many people assume that by simply having insulation this automatically equates to having good insulation, not realising their materials are far more likely to be of poor quality, and are likely not doing very much for them anymore. In most cases we've seen in Australia the insulation has been reduced to an ineffective state and/or has broken down to dust, but its not just the insulation you should be worried about. We also know that Australian roofs are the dirtiest we’ve ever seen, and considered in most cases to be a health hazard on their own. Add degraded insulation to the mix and you’ve got a much bigger problem than you think.
Almost no homes in Australia are weather wrapped and/or air-sealed. Almost all homes here have air vents in the ceiling that allow the weather to push air throughout the home, as well as potentially harmful dust particles and car exhaust to pass freely into the homes cavity spaces. Almost no fans are covered or filtered and most home owners with downlights will notice dust falling from them from time to time. Almost all moisture ducts blow moisture INTO the roof, not OUT of it. All of these air openings allow dust to pass freely without filtration, and can effect your lungs and breathing/ trigger asthma and put residents at risk of a whole range of health related problems. In many cases these illnesses and/or symptoms are a direct result of living under a roof containing degraded insulation that is more often than not riddled with harmful fine-dust particles that you potentially breath in daily; especially if your Air-Con filtration &/or ducting is poorly serviced or in need of replacement. This risk is especially present in homes containing old blow-in insulation products of any kind, which will in most cases contain dangerous levels of lead and in some cases asbestos.
*****If you or a family member, relative, friend or work colleague happens to suffer from breathing problems and/or has any lunge or throat conditions, especially if you/they were not born with them and/or can recall developing such conditions or experience existing conditions worsening over time following a move into a new home or town area... we implore you to have your/their insulation inspected by a reputable insulation expert IMMEDIATELY.
I Was Told They’d Just “Top-Up” The Old Stuff.
We find it humorous that the very same people telling you that you do not need a double layer want to lay new batts over the old disgusting ones. We argue that they’re giving you a Double Layer in doing so, but not a very nice one.
Topping-up a degraded and ineffective base layer full of rodents, faeces, leaves, carcasses, heavy metal dust and other toxins is hardly providing a service. If you hired anyone to clean a filthy home and they spread newspaper to hide the mess and covered the areas of concern with clean towels you’d all throw them out of your homes, so why do so many people actually pay these so-called installers knowing their strategy is to half-arse it?
You’re already breathing the dust in, but when someone installs batts over dust, the dust plumes everywhere and finds its way into the deepest recesses of your home’s interior cavities; and your lungs. We would like to see this practice outlawed, but mostly we don’t want to see any more of you fall for this questionable yet surprisingly common practice. See Vacuum section below.
Why Is Roof Vacuuming Required? What Should I know?
Roof vacuuming is fast becoming the most important and by far the most involved aspect of working in residential insulation. This is because in order to provide services for sustainable living under the government’s sustainability incentives, one must be certified, and certified installers are required to vacuum dirty roofs.
What you need to know is your roof breathes the outside air, its naked, its exposed to the elements and its collecting dirt, grime and residue, animal faeces, car exhaust/smog, leaves, atmospheric moisture and in most cases the mess goes well beyond potential for heath concerns and fire safety. In other countries many of these super dirty inner-city homes would be condemned and demolished long before considering renovations.
The new methods and expectations under the new industry certification is that removal and vacuuming is now standard practice. Vacuuming is a requirement under the new practices and the requirement for the equipment falls under existing standards mentioned below. Insulation removal and vacuuming is the most dangerous aspect of insulation retrofit, and it requires well trained staff and serious heavy duty custom engineered equipment to extract toxic micro dust safely. The very best of us operate vacuum rigs with H-14 filtration, which is required by law.
HEPA does not mean H-14, but everyone just says “HEPA”, so it is important to research and know the difference in HEPA classes, and ask specifically about their vacuum’s H-14 certificate.
THIS IS IMPORTANT: When you invest thousands of dollars to remove dust that can lead to serious health problems, you want to be absolute in your confidence that the machine was strong enough not to leave the heavier more dangerous materials and metallic compounds behind without endangering the entire neighbourhood in the process. Equipment matters.
We share our competitor’s opinions concerning roof dust and can tell you most of the information out there is based around fear of serious health issues for good reason, and the information is accurate. Roof dust of the nature found in Australia is no joke. Australian roof dust is a danger to everyone breathing it, and all of Australia is doing this on a micro level daily. Australians suffer more asthma and breathing illnesses per capita than all the world, and the dust inside the cavities within our terribly built homes and structures is most certainly the leading cause. Jason York stakes his entire reputation on that fact.
The government is certainly aware our cavities are beyond filthy, which is why existing standard AS 3544-1988 makes specific mention of the required need for H-14 grade HEPA filters.
Most Insulation vacuum equipment, including ALL commercially available factory models, do not have this class of filter. In fact, most insulation removal vacuums don’t even have filters they just have a giant catch-bag, and the ones that do carry HEPA don’t exceed H-13.
There’s a huge difference in HEPA 13 and HEPA 14. H-13 won’t handle 100+kg of roof dust and 100+ years of led dust from smog, and it certainly won’t contain it once it sucks 30+kg of it. Within a few jobs these filters are destroyed and clogging pressure. If you show pictures of what we regularly remove from roofs, the manufacturers would tell you themselves their vacuums are in now way designed to take this much of a beating day-to-day. Anyone that says otherwise doesn’t work inside a roof.
Our vacuum rig can handle the heaviest dust imaginable. It can handle hundreds of kilograms of it, all day every day, without losing pressure, and without leaking dust. Our Custom Enduro-Vac is an indestructible beast that devours all in its path. It has numerous stages of filtration and enough pressure to crush an oil drum. This level of durability and performance guarantees that by the end of the job the vacuum is still sucking at the same pressure as when we started, ensuring a consistent finish no lessor vacuum can match.
However, like a Marine and his rifle, the vacuum is useless without an experienced operator.
***Check out our custom Enduro-Vac***
Why York Insulation Wants Blow-In/ Loose-Fill Insulation Outlawed.
York Insulation doesn't mince words and we're unsympathetic of how badly the truth hurts, and the truth is that loose-fill insulation is the absolute dumbest investment you can make for your home. In all honesty we feel its a service that ought to be banned from sale in Australia due to its lack of long term performance and the health risks associated with it's degradation.
You will be sold on "better coverage" by covering the timber and negating thermal bridging as discussed in the aforementioned sections of this page. Better coverage that negates thermal bridging is obviously what you want, that’s why we sell Double Layer. However, those who offer Blow-In or Loose-Fill will try to convince you only their products can achieve this thickness and coverage. Fact is, Batts can do it better, they just need to be laid in two layers. Secondary layers of insulation are often referred to as "Top-up", which is a very common practice here in Australia, one that also should be banned for health reasons.
The first problem with blow-in or loose-fill products is gravity. Most customers will notice the blow-in insulation they purchased typically won't last for many years and ultimately matts down below the timber they paid to have covered. This is also why calculating R-Values for blow-in on a per-home basis is so difficult and in most cases wont be sustained for long. Regardless of brand, material or R-value, the depth of your blow-in insulation will settle, and within less than 10 years on average the materials will have "Matted" themselves to sit BELOW the timber supports you paid to have covered. 5 years or less if children are crashing through the home vibrating the structure. In addition to this, blow-in materials in most cases break down so much the only thing left is a thick layer of fine-dust; toxic and harmful dust at that. This dust is kicked up daily by your ceiling fans, drafts created from whirlybirds, holes in air-con ducting, scurrying rodents, wind gusts, whenever opening manholes, etc. This dust can and will enter your home, and you'll most certainly breath it in. Most of you already do breath this dust. This dust falls into all of your wall cavities and often can be seen "dripping" from the gaps between your downlight housing frames and your gyprock ceiling fans/vents.
The next issue with loose-fill is that it's loosely filled, so the timber supports can't support anything. Unlike a double layer of batts, the loose materials aren't solid so they cannot hold any rigidity, and therefore the entire roof's materials will rest solely on your gyprock. Many will simply “Top-up” the sagging fluff with more fluff without considering the extra weight is not supported like timber holds & supports batts.
The problem with that strategy is the weight of insulation vs the carrying capacity of Gyprock, which is NOT load bearing. On average lose-fill insulation will weigh between 5-7kg/m2, and higher when degraded to dust and/or has absorbed moisture. The average home containing loose fill will have between 60kg - 200kg worth of dust resting solely on the ceiling gyprock. The largest removal completed by York Insulation contained 620kg of roof dust in a space no larger than 130m2. The entire ceiling was pulling down and sagging and was ready to collapse into the entire home; that happens a lot in Australia.
Earthwool Batts not only perform better for longer, especially in two layers, but they only weigh 1.5kgs/m2 per layer (based on weight of Earthwool R4.0). Random popped screws and cracks form in your ceiling when too much weight is pushing down on it, and in almost every ceiling collapse the weight of the insulation is to blame. Topping up loose-fill insulation is a really bad idea every time, especially if it's topped up with more loose-fill.
Besides the fact that this tremendous amount of weight can push down hard enough to collapse your home's ceiling, but once aged beyond usage it's also highly toxic to your health in virtually all documented cases, and negatively affects the air quality of the home 100% of the time. Don't take our word for it, do your own research. The saying in the United States is that “If it’s in your roof, its in your home. If it’s in your home, it’s in your lungs”.
Last but not least the fire retardants used in most blow-in or loose-fill products cannot be exposed to moisture/water at all whatsoever, otherwise when H2O contacts the fire retardants the chemical reaction will off-gas Ammonium Sulphate. Your roofs do a terrible job of keeping moisture out considering they’re designed and built to let moisture in, so if you have a blow-in/loose-fill product it’s likely sagging, has likely gained weight in moisture absorption as well as gassed the roof space with Ammonium Sulphate during its first few summers.
Are Whirlybirds A Good Investment?
Firstly, when we see other countries using whirlybirds we have to recall that they’re built to a far higher standard. There is layers to those roofs, they’re insulated and properly ventilated. When moisture backflows or rain splashes into the whirlybird, 100% of that moisture finds it’s way OUT of the home. That obviously isn’t possible in Australia, for our roofs are neither properly ventilated, weather-proofed or complete for that matter.
Although there’s no denying the positive difference felt in summer following installation of whirlybirds, because a lot of heat can and will escape, they ultimately cause far more harm than good to your home’s infrastructure. Unless your home is metal frame then whirlybirds are structural suicide in Australia, but even still, insulation degrades faster when exposed to moisture, so whirlybirds on homes in Australia are almost never a good idea because you’re essentially paying someone to shave decades off your home’s life. Remember; it’s an over-glorified overpriced shed, not a house.
Australia is the hottest, driest place on Earth, and that makes it’s residents forget that most of the coastal region is actually very humid throughout most of the year; especially when temperatures rise and fall as often as they do during seasonal changes. If your home’s wood has cooked for one too many summers the chemicals treating the timber would have evaporated and your entire structure can now mould, so allowing extra moisture to backflow into a hot warm dark cavity is counterintuitive, and truth be told we’re always shocked when licensed professionals don’t consider what should be common sense when they advise you to put another hole in your roof instead of advising you the insulation in your roof is defective or non-existent.
Many of you experienced the heavy rains of La Nina’ and found out the hard way what can happen without a properly built and ventilated roof. Moisture enters the timber, causing it to expand and contrast when heated and cooled each day and night, because the laws of physics demand that they will. Most roofs in this country after enough years look noticeably warped and do not resemble anything remotely close to being flush, especially in tiled roofs, and moisture damage to the wood is the cause of this common feature of Australian roofs. The more this process happens the faster it will happen.
End of the day; moisture must be vented out and away from the roof and home, and should never be given opportunity to enter the home freely, this is why other countries wisely air-seal the entire home from the outside atmosphere and ensure all internal moisture finds its way out. If your roof is so hot you want to put holes in it, you need new Earthwool insulation.
How Do I Assess My Roof Insulation Needs?
If it’s not Earthwool, and its not newer than 20 years, it belongs in a landfill. If its not Earthwool and its brand new, it still belongs in a landfill. Earthwool is the highest performing Batt by a significant margin, and then there’s a big gap where the rest battle for the title of first loser.
If you have no insulation, you need insulation.
How Do I Assess My Underfloor Insulation Needs?
If you’re living on a raised home with a subfloor cavity, you will never get the full value of ceiling insulation without protection from subfloor radiation & convection. Carpet or no carpet the home will never retain heat without Underfloor Insulation. Period. Underfloor insulation also will not work without good ceiling insulation, so for those living off the ground you need both applications to be efficient. They work in tandem.
How Do I Get A Quote?
Our “Get Quote” page has a form where you can provide us with your personal details and as much information as can be provided, including photos of spaces to be inspected. In most cases once an address is provided, the measurements can be accurately obtained from the internet via satellite imagery, building software and other programs. If measurements and photos can be obtained upfront, we can generate an accurate quotation without leaving the office. If not, then we schedule you into the next “quote day”, where we will dedicate the entire day to visiting as many of you as we can manage.
All we need for underfloor quotations is measurements and photos of the access, as we only use one product for all underfloor applications and so there is no need to size the joists for material order. As long as there is 400mm clearance at a minimum, we can make your home a lot warmer.
Thank you, we hope you found this helpful and look forward to working with you.