Full Answer
What is a warm roof?
What is a warm roof system? A warm roof is a type of roof construction which has an insulation layer above the rafters, and immediately below its weatherproof membrane. A warm roof construction allows heat to be conserved within a property – without the need for a ventilation system. Click to see full answer.
What is the difference between a warm deck and a cold deck/roof?
Essentially, a “warm roof” system means the roofing insulation is on the outside of the roof structure, instead of underneath, and a weatherproof membrane is applied above to ensure the roof area remains dry. Traditionally, flat roofs have a weatherproof covering on the top of the structure with insulation applied in between the rafters.
What is cold roof construction?
What is a Warm Roof? In warm roof construction, the thermal insulation layer is installed above the structural deck. This keeps the structural decking, usually constructed from timber, steel or concrete at the same temperature levels as the internal temperature of the building. To prevent interstitial condensation – condensing of any moisture that has been vaporised rising from the …
What is the best way to insulate a flat roof?
A warm deck/roof is where the insulation is placed on top of the rafters/joists and the roof covering is then placed over the insulation. No ventilation is …
Which is better warm or cold flat roof?
A warm roof is the easiest and most cost effective type of insulation and is an ideal choice for pitched roofs. On some flat roof extensions and balconies, a warm roof would increase the height and isn't possible, in this scenario you should choose a cold roof insulation.Sep 2, 2020
What is the difference between a warm roof and a cold roof?
Cold roof: As the majority of the insulation is between the rafters, the overall build-up of the roof is often less. Warm roof: The insulation is laid above the substrate layer so the overall roof construction is generally deeper.
What are the benefits of a warm roof?
Advantages of Warm Roof Insulation on the entire roof structure keeps all the components in the roof space at the same temperature. Therefore, there is reduced thermal bridging which prevents heat loss from the living room. Houses with warm roofs are less expensive to keep warm than those with cold roofs.Feb 18, 2020
What is a warm roof build-up?
A warm deck roof is the more modern roof build-up and preferable where possible. It is called a warm deck roof because the insulation is above the joists and main deck, meaning the entire roof structure is insulated (and warm). The benefit of this is that the chance of condensation within the roof structure is reduced.
Do you need ventilation in a warm roof?
A warm roof is designed to prevent any moisture from forming on cold surfaces in the roof construction. This means that warm roofs do not generally require ventilation, but there should be an Air & Vapour Control Layer (AVCL) or vapour barrier on the warm side of the insulation depending upon the detailing.Apr 29, 2021
Can you walk on a warm roof?
Yes to an extent. EPDM is designed to take LIGHT foot traffic during installation and for occasional cleaning or maintenance. If you require more use than this, i.e. for a balcony then there are additional materials that can be laid over your EPDM for a more durable solution.
How do you convert a cold roof to a warm roof?
The correct way to change a cold deck to warm deck.Block existing ventilation throughout.Take out any insulation that exists below the deck, keeping it here will create interstitial condensation.Fix PiR insulation over the felt. ... Fit waterproof membrane eg single y membrane.Plasterboard and skim to underside of joists.Jun 13, 2018
Do you need a vapour barrier on a warm roof?
To use EPDM for a warm deck flat roof construction, solid (closed cell) roof insulation such as Kingspan or Celotex should be placed on top of the roof deck, rather than in between the rafters. A vapour barrier will then need to be installed to reduce condensation in the roof structure.
How does a warm flat roof work?
A warm flat roof or a built-up roof (BUR) is one where all the insulation is above the joists/deck, making them part of the warm fabric of the building. The insulation is immediately below the waterproofing layer. The vapour control layer is above the decking but below the insulation.Jul 13, 2017
How much does it cost to insulate a warm roof?
When insulating one, you're aiming for a value of 0.25 W/m2K or less. To achieve this, you should insulate your flat roof with insulation boards totalling around 150mm thickness.Feb 24, 2021
What is a warm roof?
Essentially, a “warm roof” system means the roofing insulation is on the outside of the roof structure, instead of underneath, and a weatherproof membrane is applied above to ensure the roof area remains dry. Traditionally, flat roofs have a weatherproof covering on the top of the structure with insulation applied in between the rafters.
Why do we need a warm roof?
Warm roof systems negate the need for these air flow gaps, as the insulation is outside of the timber structure, therefore eliminating any chance of condensation. As the name suggests, warm roofs offer superior insulation to traditional flat roof systems which means a warmer, drier, quieter, and most importantly, weathertight environment.
Why do businesses use warm roofs?
Warm Roofs. As warm roof systems improve ventilation, reduce condensation, and minimise noise, they are a great solution for many types of business premises. They can also be retrofitted, so you don’t need to remove the existing roof material, which is great for your tenants.
Can flat roofs cause condensation?
Traditional flat roof systems can increase the risk of condensation, leading to issues with cold, damp, and mould. If you are concerned about poor ventilation and condensation affecting your people or product, maybe it’s time to consider a warm roof system.
Do flat roofs need vents?
However, vents are needed between the insulation and the timber framing to allow the circulation of air, otherwise condensation occurs on the timber rafters.
What is a Warm Roof?
In warm roof construction, the thermal insulation layer is installed above the structural deck. This keeps the structural decking, usually constructed from timber, steel or concrete at the same temperature levels as the internal temperature of the building.
Material Choices for Warm Roof Construction
IKO Polymeric manufactures a huge variety of specification roof coverings. Our next generation IKO Spectraplan Single Ply Roofing Membrane – a combination of the best characteristics of thermoplastics and elastomers – delivers optimum results both during installation and in service performance.
How does condensation form on a roof?
Warm , moisture-laden air is allowed to flow through the insulation and when it comes in contact with the colder sub-structure of the roof , condensation can form on the structure of the roof. Proper ventilation is required to remove any air that infiltrates the space above the insulation thus preventing condensation from forming.
What is cold roof construction?
What does it involve? Cold roof construction, is what is found on most older flat roof buildings and almost all houses both old and new.
Is a flat roof better than a warm roof?
A warm roof has many benefits over a cold roof installation. It is more thermally efficient and despite its higher cost of construction, lessens overall heating costs, thus saving money over the long-run. A flat roof installation, due to the warm air being held below the solid surface of the roof, does not need to be ventilated.
Can a sloped roof be used as insulation?
A sloped roof done with standard construction is not capable of handling the additional weight of insulation so stronger roof trusses must be used. If you are thinking of building a new building or home, talk to your architect about warm roof options and how much money you will save in energy costs over time.
Can you re-roof a warm roof?
If you are thinking of re-roofing your home or building, the option of a cold or warm roof is already done for you. The roof must be designed to withstand the additional weight of the warm roof or the entire roof must be reconstructed . In most situations you have to live with whatever roof your building or house came with.
Do flat roofs need to be ventilated?
A flat roof installation, due to the warm air being held below the solid surface of the roof, does not need to be ventilated. There is no air-space between the roof and the warm air, thus there is no condensation. When designing a warm roof, the architect must take the added weight of the insulation into consideration.
Can flat roofs be cold?
When you think of roofs, chances are you believe the only way they could be warm or cold is in the summer or winter. The truth is, flat roofs come in two different configurations depending on how the architect designed it.
How is a flat roof warm?
A warm flat roof is formed by placing a layer of insulation over the top of the roof structure. Due to the insulation being over the top of the roof, the timber structure beneath is warm, which is why the term ‘Warm Roof’ is formed.
What is a warm flat roof?
In a warm flat roof construction, the insulation is positioned above the structural deck and no ventilation is required. 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, ...
What triggers part L of the building regulations?
These factors can trigger part L of the building regulations document: 1. If you strip the covering of an old flat roof, you automatically trigger part L of the building regulations document. 2. If your current insulation is poor, then you trigger part L of the building regulations document. 3.
Why is a deck warm?
A warm deck also provides added protection from the dangers of condensation as the structure is kept warm, at a temperature above dewpoint, by the insulation above it. Therefore water vapour which enters the roof structure from the room below will not have a cold surface on which to condense.
What happens if you don't comply with building regulations?
If you do not abide by the current building regulations, then you will not receive a building regulations compliance certificate which could affect the sale of your house should you wish to sell it.
What is silicone roof coating?
Silicone roof coatings are a great option to repair or rejuvenate an existing roof for many reasons, such as: 1 All the tiny holes, cracks, punctures, etc. will be filled and watertight 2 No seams 3 All the flashings and penetration become part of the monolithic roof 4 The entire roof is sustainable and renewable 5 You’ll likely save money on your energy bills because silicone is white, which reflects the sun, keeping the roof cooler than a darker color.
Who is Greg Palya?
Greg Palya is the Digital Content Manager of West Roofing Systems, Inc. He has a B.S. in Marketing from the University of Akron and an MBA in Marketing from Walsh University. When he’s not trying to teach others about spray foam roofing and silicone roof coatings, you can find him on the basketball court or golf course.
What is XPS board?
Extruded polystyrene (XPS) is the most suitable type. The XPS boards are placed over the membrane and held down by a layer of ballast or loose pavers on top. If ballast is used, a filter fabric should be placed between the ballast insulation to prevent damage to the XPS.
What are the disadvantages of low slope roof insulation?
The location of the insulation in a conventional roof system poses a few disadvantages. When inspecting, look signs of the following: 1. Membrane aging. When insulation is used directly under the roof membrane, solar heat does not readily pass through the roofing system, ...
What is a PMR roof?
Protected Membrane Roof (PMR) In a protected membrane roof, also known as an inverted roof membrane assembly (IRMA), the insulation is installed on top of the membrane. The insulation may be exposed to water, so it should have minimal water-absorption characteristics.
What happens to the roof membrane when the sun goes down?
Then, in the evening, when the sun goes down, the entire membrane’s temperature returns to air temperature rather than the interior temperature.
What causes moisture in a roof?
Moisture within the roofing system. The interior and exterior surface temperature range caused by thermal insulation may increase the likelihood of water vapor entering through the warm side and condensing within the roof system.
Why does my roof have a rapid expansion?
Rapid daily temperatures are caused by the lack of heat transfer through the roof assembly.
Does solar heat pass through a roof?
When insulation is used directly under the roof membrane, solar heat does not readily pass through the roofing system, which increases the roof’s surface temperature. This, in turn, accelerates the oxidation and evaporation of volatile oils in bitumen-based membranes.
