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3D Drawing Family House Insulation

A quarter of a building’s heat is lost through the roof if left uninsulated. Installing effective insulation in an attic, loft, pitched or flat roof is an effective way to reduce heat loss and slash energy costs. Roof insulation, done right, should pay for itself many times over in a 40-year lifespan. It also makes buildings more environmentally friendly at a stroke. Knauf Insulation provides insulation solutions for

Flat roof Pitched roof

3D image flat roof insulation

Flat roof insulation

Flat roofs are increasingly found on modern buildings, extensions, commercial premises and purpose-built facilities such as supermarkets, warehouses and sports centres, and have strengthened their role as the most important component of a building's structure - not only protecting against wind and weather, but also becoming increasingly used as a "power plant" for renewable energy. Insulation can be sandwiched between internal rafters or fitted on top and finished with a weatherproof layer, and some can also be used as external space, or for green roofs or solar panels. Existing roofs and roof sections not initially planned for photovoltaic systems are an important source for energy generation today, or in the near future, for the expansion of generation capacities.

Flat roof insulation: built to last

Flat roofs require an effective and complex waterproofing system and should be installed by experienced professionals. Basic waterproofing consists of applying two or three coats of a single-component polyurethane or methacrylic resin over a primer. If necessary, silica elements can be integrated into the last coat. Cracks can be repaired using a reinforcing sheet, either locally or across the entire surface. Our Flat roof solutions are tested in the harshest environments. Flat roofs are particularly sensitive to wind load and fire. They are independently certified, by FM Approvals, for fire safety and resistance to wind.

Understanding roof insulation

Cold Roof Timber Deck Flat Roof UK

Cold roofs

Cold roof have insulation between the rafters, allowing for ventilation space below your roof deck. Install baffles or make sure there’s a minimum of airspace between the roof deck and insulation. This insulation method is often chosen for renovation.

Mechanically Fixed Single Ply Solution UK Flat Roof

Warm roofs 

Warm roof are insulated above the rafters. Air sealing hot roofs is critical. Because the insulation is so close to the roof and you want to avoid unwanted moisture buildup, these roofs will need to be completely sealed off.

Built Up Metal Roof UK Flat Roof

Metal roofs

Built-up metal roof systems typically consist of a low profile metal inner liner sheet, separated from an outer, higher profile metal weather sheet and are typically assembled on site. The cavity between them is filled with a layer of insulation to provide the specified level of thermal performance. As well as thermal performance acoustic performance is also important.

Green Roof Urbanscape 3D View Layers

Green roofs

A green roof or living roof is a roof of a building that is partially or completely covered with vegetation and a growing medium Urbanscape® Green Roof System insulation concepts breathe new value into the role of buildings in urban planning. Is a complete, lightweight and easy to install system with high water retention capacity designed for green roofs on residential, non-residential and industrial buildings.

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Solar panel installation

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The installation of solar panels on flat roofs is increasingly common, particularly on larger roofs. While photovoltaic systems on a pitched roof follow the slope of the existing roof, flat roof systems require the installer to determine their own inclination so that the system can be designed to optimally generate solar energy. The solar panels are installed on a bracket that tilts the panel, usually to around 30 degrees. Solar panels on flat roofs are usually mounted on a tub, weighted down with ballast (gravel, flagstones, bricks, stones, etc.) to resist high winds. Alternatively, the panels are mounted on metal frames. This is usually dependent on the construction of the building and its location.

Our digital application enables optimal placement of inclined roof panels. Its use allows each panel to be clearly marked on the drawing, which is then used on site for rapid installation.

The application allows cost calculations as a basis for quotations and the creation of an accurate bill of materials with the optimum use of partial materials.

Flat roof insulation case studies

Special application for inclined flat roofs

Knauf Insulation has developed an application for inclined flat roofs. Our digital application enables optimal placement of inclined roof panels. Its use allows each panel to be clearly marked on the drawing, which is then used on site for rapid installation. The application allows cost calculations as a basis for quotations and the creation of an accurate bill of materials with the optimum use of partial materials. What to look out for when installing When installing products on flat roofs, it is important to install them in the correct direction. For this reason, we have introduced line marking to help the installer lay the panels in the right direction and thus maintain their rigidity.

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3D illustration of pitched roof insulation Knauf

Pitched roof insulation

Pitched roofs are commonly found in traditionally constructed timber-framed houses. Often older homes lack proper insulation in the roof cavity, leading to inefficient heat retention and high energy costs. There are different ways to avoid this. You can choose to insulate a pitched roof, either with Rock Mineral Wool or Glass Mineral Wool or a combination of both. Rock Mineral Wool has a slightly higher insulation value, whereas Glass Mineral Wool is less rigid, more manageable, which helps fitting the insulation in the tricky corners of the roof cavity, dormer windows… Both solutions offer similar levels of thermal and acoustic performance as well as A1 fire protection.

Different ways to insulate a pitched roof

When converting a roof from the inside – while renovating, for instance – the insulation must be applied between the rafters. An additional layer of insulation can be installed below the rafters to provide further thermal and acoustic protection.

When building or replacing a roof, insulation should be installed from the outside using a layer of rigid insulation boards (‘sarking’) above the roof structure. An extra layer of insulation can be applied between the rafters to provide additional thermal and acoustic protection.

between & below rafters above rafters below, between & above rafters

Loft insulation increases comfort & energy efficiency

When you choose to renovate your loft, insulation makes all the difference. Whether you do a full loft conversion, add living space or create an extra bedroom or office space, it is an excellent opportunity to install better insulation. Even in smaller projects, such as creating extra storage for hot water tanks, insulation is always the right choice. Up to 30% of the heat in the house can be lost through a poorly insulated roof. Insulation reduces this heat loss and offers many other advantages.

Knauf Insulation Pitched Roof Products Germany

Insulation between and below rafters

Insulation Between and Below Rafters 3D Image Pitched Roof

Insulation below and in between rafters is the preferred way to insulate in renovation projects from the inside - known as cold roof insulation, especially when there are no restrictions in height.

It is essential that the rafter insulation forms a closed insulation layer without gaps or weak points to maximise thermal and acoustic performance. Even small gaps in the insulation can compromise its thermal and acoustic properties. 

That is why it's important to make use of the compressible nature of the materials to ensure full contact to wooden rafters and between individual insulation components. 

Increasing heat retention and soundproofing

Adding a second layer of insulation below the rafters will have an immediate positive effect on the R values (thermal efficiency) and acoustic benefits. 

Use wooden battens or metal profiles to hold it in place.

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Insulation above the rafters for new build & roof replacement or repair projects

3D Drawing Roof Insulation Above Rafters Knauf

Warm roof insulation is when the insulation layer is installed above the rafters. it envelops the roof structure within the insulated envelope of the building offering many advantages:

              • Reduces thermal bridges

              • Provides continuous airtight layer of high performance  insulation

              • Maximises space available below the rafters – as insulation does not intrude the roof cavity

Because warm roof insulation needs to be installed below tiles or roof felt, it is ideally suited for new build projects, or as part of a renovation where the roof is being repaired or replaced.

Increasing the R value of warm roof insulation

To increase the R value (thermal efficiency) of the insulation, a second layer of mineral wool can be installed between the rafters, ensuring the material compresses snugly between the rafters with no gaps.

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Insulation below, between & above the rafters for new build

Insulating below, between and above the rafters is the most sustainable way to insulate a pitched roof and the best way to meet the building requirements of tomorrow. Three layers of different, non-combustible insulation materials between, on top of and underneath the rafters significantly exceed the requirements of the Building Energy Act (GEG). This method is suited mostly for new build projects.

This very high-quality solution offers many advantages, such as:

             • Minimize energy losses

             • Reduce external noise

             • Reduce heating requirements

             • Ensure breathability of the roof

             • Ensure Fire Protection

             • Offer high compressibility


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