For roofing contractors in the southern states, it’s a welcome relief to the brutally hot summer roofing season. A flat roof installation, due to the warm air being held below the solid surface of the roof… Further, moisture reductions can help increase the roof’s longevity and the lifespan of roof shingles, so maintaining a dry roof space becomes very important. This allows air to circulate. Whether or not a hot roof is a superior setup depends heavily upon climate, homeowner needs, and building plans. This air space is designed to do two things. Hot Roofs act as a thermal break and will prevent ice dams from forming on the roof during winter months. For contractors in northern areas, it means it’s time to adapt to the winter roofing season. Which makes sense, as this space is otherwise empty, and so it’s a simple, low-impact way to insulate a roof. The term hot roof comes from the earliest days of insulating attics. However, it must be pointed out that a cold roof requires more work and isn’t as thermally efficient as a warm one. Or, if you’re close enough to the coast that your roof will be exposed to salt and cold winds, EPDM may be a better choice to withstand these stressors than TPO. Insulate the ceiling adequately. Hot Boxes are ideal for cold weather storage, freeze protection, transporting, job site heating, remote location use, and winter roofing. It provides the better architectural appearance to the building; It is easier to make the flat roof fire resistant. A warm roof construction has many benefits over a traditional ‘cold roof’, essentially it is a ‘breathable roof construction’, which allows moisture to escape which in turn prevents damp … In hot climates the roof temperature will be much higher on an un-vented roof, resulting in much shorter shingle life. CONS: e.g do we simply need to achieve a Building Regulations minimum standard, or we looking to improve upon that? Is the chosen design solution ‘build-able’? Normally roofing in North Texas is hot and sunny, but today it is 35 degrees outside! Address: Unit 5 Lower Healey Business Park, Froom Street, Chorley, Lancashire PR6 9AR. How important are accurate wind load calculations? Hot Mop Roofs Vs. Torch Down Roofs By Erin Schreiner Hot mop roofing and torch down roofing are both popular roofing options for flat-roofed structures. Controlling ice damming by keeping the roof cold. Well it may be daunting to anyone who cannot fully answer each item. In cold roofs, the outside air is allowed to freely flow under the roof sheathing. Well we have produced this guide to warm roofs and cold roofs: what’s the difference and when should you choose them? For professional advice and support choosing between a warm roof and a cold roof, or a quote, get in touch with the professionals today, here at Enviroply Roofing. If it is not possible to amend the compatibility of construction or insulation can an adequate compromise be achieved? Orient roof planes east to west rather than north to south. In general, it is suited to external outbuildings. A warm roof construction allows heat to be conserved within a property – without the need for a ventilation system. Whether hot or cold, fluid-applied waterproofing systems have the advantage of being monolithic and seamless compared to sheet membranes. Most studies show anywhere from 1° to 5° maximum increase in surface temperature during the sunniest part of the day, while at night the surface temperature drops faster than a regularly vented roof. When it is too cold to roof it can be hazardous to the shingles. The term hot roof comes from the earliest days of insulating attics. Enhancing roofing material life … They perform well in both extremely hot and bitterly cold conditions — perfect for the weather extremes common across New Jersey and nearby states. For example, if you’re reroofing an exceptionally large roof, you may need to choose EPDM to stay under your budget. – Are you, as a building designer asking your contractor to achieve the impossible. The roof structure, above the ceiling, is not insulated at all. Want to know more about Energy Efficiency? Cold Roof Construction – requires that a suitable ventilated air space exists above the insulation layer, within which the air is constantly mobile, being replenished by fresh incoming air, whilst  the air resident within the void space is being expelled via a natural vent action at another point. So warm roof or cold roof, which would you choose? But they note that light roofs may increase energy costs in cooler climates. Some people believed insulation was actually a heat source, even though in actuality it is a barrier between two areas of different temperatures. Proven roofing method. In climates that remain cold for a sustained period, unvented roofs can cause more harm than good. The Breakdown – Warm Roof vs Cold Roof. We can provide a variety of effective roofing solutions for any commercial or industrial property. Additionally, cold weather applications require six (6) nails instead of the usual four (4). And should you create a warm roof or a cold roof? Unfortunately, the term hot-roof is a misnomer as the roof really is not that much hotter than a normal roof. There are pros and cons to both a warm roof and a cold roof. Basically, the term “cold roof” refers to a traditional roof, or vented roof, while “hot roof” refers to a roof that is not ventilated and which has foam insulation attached directly to the roof sheathing. When the time comes to re-roof your home, the hot-mop option is a common one. What’s more, a warm roof allows heat to be conserved within a property without a ventilation system needing to be installed. Ventilated cold roof or warm roof with insulation boards atop sheathing which serves to raise the dew point above the structural members of the roof. Namely the insulation layers. In a cold roof, the insulation is applied between the rafters, but in a warm roof, the insulation is applied on top of the existing roof surface. New build or retro-fit of insulation, the list is pretty much the same. In hot roofs, the insulation is typically installed close to the roof sheathing, but the main characteristic is the space under the sheathing is closed to fresh air flow. In pitched roof construction thermal insulation can be placed horizontally at ceiling level (cold roof); inclined along the line of rafters (warm roof) or positioned within the roof structure to form an insulated void (room-in-roof) which can result in warm and cold roof areas. http://go.askthebuilder.com/NewsletterSignup founder Tim Carter demonstrates one type of cold roof system. Metal Roofs. What Is A Cold Roof? In a cold weather, such roofs … Good workmanship, especially around flashings, is critical for a long service life. Metal roofs are the material of choice these days in stylish warm-climate cities … Even though the term “hot” roof … Yes, asphalt shingles can still be installed successfully in cold … Warm Deck/Roof –. The roof can be used as terrace for playing or for sleeping or for other domestic purposes. The definition of a warm roof on pitched roofs relates to the space between the pitch of the roof … It is perhaps surprising, and certainly unfortunate that some building professionals, and contractors are under a misapprehension as to the precise requirements in order to achieve warm roof, and, or cold roof construction. Perhaps the greatest advantage to modified bitumen is their versatility. Roofs Have Two Categories: “Cold” and “Hot” A properly constructed “cold” roof maintains a continuous air space between the underside of the roof and the … A basic understanding of your roof system and the challenges it faces can help to identify the sources of problems. Think about the electric, plumbing and HVAC that runs through many attics. 4. Only of course if you understand the basic principles that operate in the design / installation of the insulation materials. Roofs get made in such a way that they withstand the climatic changes by adapting accordingly. Energy.gov recommends lighter-colored roofs for houses in warm and hot climates. The term Hot Roof is a bit misleading, as the shingles only get a few degrees hotter than a regularly vented roof. Further, moisture reductions can help increase the roof’s longevity and the lifespan of roof shingles, so maintaining a dry roof … This is less of a concern for slate and similar product roofs. Where a cold flat roof does incorporate insulation this is in the form of mineral wool stuffed in between the timber rafters/joists, with a minimum 50mm (2 inch) air gap left clear in between the insulation and the roof deck. Air from outside is permitted to come in through the soffits and exit through the top of the roof which creates a cold attic during the winter months. An architect makes the usual decision of the pitch. The average lifespan for a 3-ply hot-mop roof in Florida 15 years. They are also an excellent material for repairing existing bituminous roofs. Ideally, the temperature in the roof space should be between 28-30 degrees with a constant flow of air, regardless of whether the temperature outside is cold or hot. On a flat roof this could be ‘air in’ at one ventilated facia soffit, and ‘air out’ via an opposite ventilated facia soffit. For condensation to form it would need cold too meet hot air but now its all hot air inside the building until the top of the warm roof insulation. Cold weather … The resultant action of which does not allow condensation to occur to any significant effect. If insulation and construction are incompatible, is it possible to alter the construction and, or insulation so that they are? Throughout the course of the year the roof deck and all below it is kept at a temperature close to that of the inside of the building, therefore the roof structure is protected from extremes of hot and cold, lessening the potential for damage caused by thermal movement. This method is intended to deter ice dams by keeping the roof cooler. A cold roof refers to the type of roof that has the insulation layer installed between or under the rafters. question for Martin and others: There seems to be quite a few posts all asking nearly the same questions. In contrast, a warm roof is one designed to keep the entire roof structure warm. Both of these options provide an effective way to waterproof a roof, creating a base that will stand up to weather while keeping the inhabitants of the building dry. This air … A warm roof has many benefits over a cold roof installation. Standard Hot Boxes hold product … The main difference being with Retro-fit the most desirable design solution may be more difficult to achieve. To make an informed decision, you don’t just need to know the differences between the two options, you also need to know the different advantages and disadvantages. A warm roof construction has many benefits over a traditional ‘cold roof’, essentially it is a ‘breathable roof construction’, which allows moisture to escape which in turn prevents damp and any associated decay problems. However, this also allows cold air to enter. This is where the warm roof vs cold roof debate takes centre stage. The hot roof assembly is found almost exclusively in new construction. Long … amzn_assoc_ad_type ="responsive_search_widget"; amzn_assoc_tracking_id ="desioffi-21"; amzn_assoc_marketplace ="amazon"; amzn_assoc_region ="GB"; amzn_assoc_placement =""; amzn_assoc_search_type = "search_widget";amzn_assoc_width ="336"; amzn_assoc_height ="280"; amzn_assoc_default_search_category =""; amzn_assoc_default_search_key ="";amzn_assoc_theme ="dark"; amzn_assoc_bg_color ="000000";  Warm roof or cold roof, which would you choose if you have a choice? The sun shines hours every day, and your roof … Remember that the rake edges, areas between dormers and top few courses of the roof are the most prone to wind issues due to the wind speed increasing as it goes over the roof. “A good roof pitch would be atleast 30 degrees, although traditional vernacular samples may go as high as 45 degrees, which I think is better. This arrangement allows the deck to become ‘COLD’. 2. As a result, this type of roof is known as a cold roof. They reflect sunlight well, which is an advantage in hot climates, and they’re also designed to resist both, fire damage and algae growth. as long as you follow a ‘golden’ check list: Lets look at roofs, because potentially this where the greatest choice of solutions lies. When you put it that way it’s a daunting list. Solar Panels On Roof Vs On Ground - Solar Panels Hot Water System Solar Panels On Roof Vs On Ground Rv Solar Panel Kits Montreal Quebec Solar... Vented vs. Unvented Roofs - Building Envelope Solutions Cold Roof Construction – requires that a suitable ventilated air space exists above the insulation layer, within which the air is constantly mobile, being replenished by fresh incoming air, whilst the air resident within the void space is being expelled via a natural vent action at another point. Where should the vapour barrier be installed in order to perform it’s task? The golden check list for roofs might comprise –. They can deteriorate from moss growth and accumulated debris, so shingle roofs need to be cleaned with specialized solutions. In general, the roof structure is better protected from the more extreme scales of hot and cold weather. You create a warm roof, or a cold roof, simply by applying the layers of the roof in a different order. They are naturally better at maintaining roof temperature. Namely the insulation layers. Use a roof color with a high solar absorption value, such as red, brown, or dark gray instead of cool colors like blue, green, or white. This process offers a greater level of thermal insulation, for your whole property. To understand why, think about how a dark roof affects a home during spring and fall. It involves spreading a layer of hot asphalt on the base layer of the roof. Twitter Facebook Linkedin Google+. It possesses good insulating properties. Is a vapour barrier required, or put another way – How effective does the vapour barrier have to be? Posts Tagged: Cold VS Hot Roof. I strongly recommend accepting a 3" loss in ceiling height and putting polyiso under the rafters. The lower cost of installing a cold roof is usually one of its main advantages. On a flat roof, the top layer should should have gravel, a mineral-surfaced cap sheet, or a reflective aluminum coating. Hot mop roofing and torch down roofing are both popular roofing options for flat-roofed structures. Cold Roofs. An inverted roof, also referred to as a ‘protected membrane’ or ‘upside down’ roof, is form of flat roof in which the waterproofing layer is beneath the thermal insulation rather than above it. Thus, your unventilated roof … Thus, your unventilated roof is indeed a hot roof. A typical roof pitch in the UK for a traditional house will be 40°- 50° but at most it can go up to 70°. One of the primary advantages of cold process roof systems is their relative ease of application. Well, let’s take a look at the details. Seams are generally where systems fail and being able to apply a membrane that is seamless eliminates these elements of potential failure. This can dramatically influence the temperature of the room, and your property as a whole. The pros of the hot-mop option: 1. And what exactly is the difference between these two options? Warm roof insulation ensures the entire roof structure is insulated, meaning a warm deck roof is more energy efficient than a cold roof. Roofs Have Two Categories: “Cold” and “Hot” A properly constructed “cold” roof maintains a continuous air space between the underside of the roof and the insulation. First of all the design is all about what type of the many insulation products available is best suited to any given form of construction, and second, where in that construction do we put the insulation to best effect? Roofs fall into two categories: “cold” and “hot.” They can suffer from the same ailments. Comes with a warranty that is viewed as above average. But the issue of insulation, is often a contentious one. What is a Hot Roof? Roofs best for cold … Some people believed insulation was actually a heat source, even though in actuality it is a barrier between two areas of different temperatures. A properly constructed “cold” roof maintains a continuous air space between the underside of the roof and the insulation. In hot climates, where cooling expenses form the bulk of homeowners’ energy bills, energy-efficient aluminum roofing systems include an integral airspace between the metal panels and the decking. Ideally, the temperature in the roof space should be between 28-30 degrees with a constant flow of air, regardless of whether the temperature outside is cold or hot. A warm roof has many benefits over a cold roof installation. That is the deciding factor. This tends to initiate solar thaw. Here at Enviroply, we are the North West’s leading roofing experts. How to ensure the best life expectancy from a single ply roof membrane, Case study: Staycity Apartments, Mason street, Single ply roofing for a new housing development in Bolton, easy installation option when you first build a flat roof because the insulation can be applied during construction, low impact insulation doesn’t affect the profile of the building, thermal efficiency is fairly poor because of the exposed rafters, repairs involve ripping off the roof structure, which can make it more expensive, ease of installation over the top of your existing roof deck (as long as it’s in good condition), A zero-tolerance attitude to risk managed through our comprehensive H&S policies, Outstanding standards of installation and workmanship. In the case of cold roofs, the residential flat roofs have the waterproof placed directly on the deck, and any insulation would be placed above the ceiling. Whether its roof retrofits or new construction; hot roof vs cold roof, vent vs non vent, exterior insulation vs … The asphalt is applied to the roof using a heated mop. Easy to build up the low spots of the roof. A 2-ply hot-mop underlayment, protected from sunlight, might last longer. TPO roofs have been around since the 1990s. 15 Nov Share. We call this a "hot roof" design because failing to vent the roof from below not only misses a chance to avoid ice dam leaks and condensation damage in cold climates. This is because the insulation is laid over the top of the roof deck, on top of a vapour control layer, and underneath the roof covering. You create a warm roof, or a cold roof, simply by applying the layers of the roof in a different order. A roof membrane that combines the multi-layer benefits of a built-up roof. There are traditionally four main reasons for venting a roof: Removing moisture from roof cavities, structural members, sheathing and insulation. A flat roof installation, due to the warm air being held below the solid surface of the roof, does not need to … The Breakdown - Warm Roof vs Cold Roof A cold flat … These products can be torched, mopped, or cold applied, depending on the limitations of the project. Whether its roof retrofits or new construction; hot roof vs cold roof, vent vs non vent, exterior insulation vs none.....etc etc etc, all seem to be the main topics with very similar results. In some cases, the roofing contractor may elect to use cold-applied adhesives instead of a heat-welded or hot-asphalt application in these situations. The object being to design out the possibility of warm moisture laden air coming into contact with a cold surface and condensing. In cold roofs, the outside air is allowed to freely flow under the roof sheathing. There are pros and cons to both a warm roof and a cold roof. Anything underneath the warm roof insulation is now part of the fabric of the building the same as the plywood or ceiling below it. Our single ply roofing membranes are one of the most popular roofing options, and these are always paired with high quality insulation features. A cold roof in a flat roofing scenario is the one whose thermal insulator is below or inside the structure of the roof. For condensation to form it would need cold too meet hot air but now its all hot air inside the building until the top of the warm roof … Inverted roof - Designing Buildings Wiki - Share your construction industry knowledge. This article series about roof … What’s more, a warm roof allows heat to be conserved within a property without a ventilation system needing to be installed. Isn’t it? CNCD-053 V1 5/7/2019. For example, your attic space compared to your snowy roof. This “dead” space acts as a thermal barrier, blocking heat transference from the roof to the interiors below. 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