Insulating Roof Screed CI/SfB January 2004 CI/SfB January 2004 M2 P M2 P Icopal Ltd Barton Dock Road Stretford, Manchester M32 0YL Telephone: 0161 865 4444 Fax: 0161 866 9859 Technical Fax: 0161 865 8433 email: marketing.uk@icopal.com Northern Ireland Mobile: 00 353 868 175022 Telephone: 028 9037 0888 Fax: 028 9037 0747 Lightweight tapered insulation system for roof drainage Republic of Ireland Mobile: 0868 175022 Freephone Facility Telephone: 1800 409 056 Fax: 1800 409 055 www.icopal.co.uk Design Ref ICO0286 WORLD LEADER IN WATERPROOFING
International Patent: US4, 293, 341 Overview is a non-combustable roof insulation system that encapsulates high performance IRS Insulation Boards within two continuous layers of lightweight insulating concrete. The system is designed to provide positive roof drainage without the need for complex tapered boards and easily compensates for any irregularities 1. Reference Project: Florida Hospital, USA. 2. Stepped IRS Insulation Board provides the base for a positive roof fall. 3. Reference Project: Medical Facility, Jacksonville, USA. 4. Reference Project: Florida Court House, USA. in the substrate. 2 3 The completed insulation provides an ideal surface for fixing a waterproofing system, with the added benefit of positive roof drainage Benefits to eliminate ponding. is part of the FireSmart group of products, all designed to maximise roofing fire resistance during both installation and building occupation, providing the industry with its most High speed, low cost application even on complex roofing shapes Irregularities in the existing roof are rectified during the normal laying process The same standard system can be laid to accommodate any roof shape 25 YEARS The concept has been proven in use within the Icopal Group for over a quarter of a century. 25 kg/m 2 persuasive argument ever to guarantee re-insurance and limit possible premium rises for both contractor and building owner. Inherently fire resistant System can accommodate up to 400mm thickness of IRS Insulation providing maximum design flexibility is suitable for any roof substrate capable of supporting loads of 25 kg/m 2 or higher. 1 Insulation system will retain its integrity throughout the building life Side Lap Welder - part of the FireSmart range of flame free application equipment. Over time, only the waterproofing membrane will need replacing, giving low life cycle costs Environmentally friendly: by increasing roofing life the system reduces pressure on landfill and disposal cost System can only be laid by approved contractors for assured quality 2 4 3
Reference Project: St Martin s Junior School, Fitton Hill, Oldham. Installation Process The system is designed for use in both approved refurbishment and approved new-build applications. An initial layer of Adhesive Screed is laid on a suitably prepared deck (see installation instructions for details). IRS Insulation is then bedded into the Adhesive Screed and stair-stepped to provide the desired roof fall. The IRS Insulation can also be laid flat should the specification call for it. A top layer of Finishing Screed is then laid over the IRS Insulation, completely encapsulating the insulation. The lightweight Finishing Screed material itself provides secondary insulation. After 72 hours the waterproofing base sheet is always mechanically fixed followed by a choice of pour and roll, torch applied or FireSmart applied Icopal Waterproofing Membranes. 1 2 Step 1 - after deck preparation a thin layer (4mm) of FireSmart IRS Adhesive Screed is pumped to bond the IRS Insulation Boards. Step 2 - placement of the IRS Insulation Boards. Step 3 - after placement of the insulation boards the top layer of FireSmart IRS Finishing Screed is pumped between the screeding bars. Step 4 - finishing the top layer of FireSmart IRS screed to falls. Cap Sheet 3 4 Underlay Waterproofing Base Sheet FireSmart IRS Finishing Screed IRS Insulation IRS Insulation Core Fully Filled with Screed An easy way to create positive roof falls Codes of practice suggest that roofs are designed to a minimum of 1:60. The system allows total flexibility of design without resorting to any specially cut insulation. This allows the high speed, low cost creation of falls even within complex roof designs. Trouble-free compensation for substrate irregularities The nature of the system makes it a simple matter to avoid the risk of ponding on the finished roof. Minor irregularities are smoothed out by the initial adhesive screed coat, providing a suitable surface on which to lay the insulation. More serious irregularities in the roof structure can be dealt with by selectively increasing the depth of insulation to provide a uniform fall across the insulation surface. Again, this is achieved using standard components without the need for any specially tapered boards. This ability to quickly compensate for more severe irregularities is particularly valuable in situations when the fault is only discovered when on site, for example after the roof is stripped. FireSmart IRS screed fills cores in insulation boards providing anchorage. IRS Insulation Core Partially Filled with Adhesive Screed Cross Section of System Adhesive Screed Existing substrate Positive fall always maintained Layer of Finishing Screed fills in any irregular pattern of the insulation boards Screed bar in contact with at least 80% of insulation high points Minimum 25mm insulating screed 4 IRS Insulation Layer of Adhesive Screed will take up minor irregularities in the substrate 5
Performance & Cost Savings The waterproofing base layer is mechanically fixed into the top layer of screed only 225mm Centres at Overlap An unusual combination of low capital cost and low life cycle costs Conventionally, any building system that A more sustainable insulation system cost and low life cycle costs Expandable Mechanical Fixing International Patent: US4, 641, 471 Cross Section of Expandable Mechanical Fixing. The Adhesive Screed self-adheres to the substrate and needs no other fixing. The top layer of Finishing Screed provides a minimum 25mm surface thickness into which special Mechanical Fasteners are very simply inserted through the waterproofing base sheet. This technique provides major advantages: Mechanically fixing the waterproofing layer gives high levels of wind uplift resistance. Because the fixing doesn t penetrate the substrate there is no risk of cold bridging through the fixings - very important in the light of the latest Part L Building Regulations. 300mm 300mm Fixing Centres for Expandable Mechanical Fixing. The inverted wedge configuration of the Mechanical Fixings when in place gives an initial withdrawal resistance of over 18kg per fixing. This value increases as the screed ages. provides low costs throughout its life tends to have higher initial costs. This is not the case with FireSmart IRS. Capital costs are kept low by speed and ease of application, and simplicity of system components. On-going costs are then saved in a number of ways: Membrane life is prolonged When installed the FireSmart IRS system has greater mass than an equivalent rigid board system. This mass helps to stabilise the system against sudden temperature fluctuations, which in turn reduces thermal stress in the waterproofing membrane above. The system also produces a continuous surface without the working gaps and joints found in board systems. This reduces the Unlike typical rigid board systems, FireSmart IRS resists degradation by moisture even when the waterproofing layer is reaching the end of its working life. This means that re-roofing with FireSmart IRS often involves no more than removal of the waterproofing, minor surface repairs to the concrete and then the laying of fresh waterproofing. This has a significant impact on the life cycle cost of the roof system, as well as minimising disruption to the building occupants. It also saves the financial and environmental costs of removing an old insulation system to landfill. Edge Detail Incorporating Slots to allow Ventilation of the Roof Screed Treated Timber Edge Batten with 4mm x 4mm Ventilation Slots at 300mm Centres Icopal Waterproofing Expandable Mechanical Fixings Base Sheet Waterproofing and FireSmart Guarantees The complete system is supported by a 10, 15 or 20 years guarantee depending on the waterproofing system specification. Our insurance backed waterproofing guarantees mechanical stress across the membrane during normal building movement and prolongs it s life. The system resists construction and maintenance traffic The finished surface has a minimum compressive strength of Treated Timber Drip Batten cover materials and workmanship providing the installation is by approved Icopal installers who have been trained in the system 2070 kn/m 2, allowing it to retain its integrity despite any long-term punishment underfoot. application (see page 9). Additionally a The insulation retains full performance Gutter Deck IRS Insulation FireSmart guarantee will be issued on roofs waterproofed with FireSmart membranes. This guarantees the fire performance of the membrane for 20 years. throughout its life Rigid board systems containing HCFCs will suffer depletion over time, known as thermal drift. The effect is that initially high R-values are Fascia Finishing Screed Adhesive Screed 10 YEAR 15 YEAR 20 YEAR TM reduced. contains no HCFCs and the IRS Insulation, fully encapsulated within the concrete screed, retains its initial thermal performance throughout. 6 7
Performance Comparison Services & Technical Data Fire Rating Slope Attachment Mechanical Stresses FireSmart IRS FireSmart IRS provides a totally noncombustable insulated roof substrate. Slope is attained by stair-stepping IRS Insulation. Substrate irregularities or low spots are easily corrected with a layer of lightweight insulating Finishing Screed, ensuring positive slope. No special boards are required for crickets and saddles. Permanent attachment of IRS Insulation to the substrate is achieved without the use of fasteners. Attachment of the IRS insulation is achieved by the two layers of screed filling the holes within the insulation board and creating a series of locking studs. The encapsulated insulation design provides a stable monolithic surface to accept the roof membrane system. Typical Rigid Board Installation Insulation is the most vulnerable part of any roofing system to fire and must be protected. Specially tapered boards are necessary to achieve slope. This application requires a complex system of numbered, colour-coded shapes and sizes to properly match up boards. Corrections on site are not easily accommodated, often requiring labour intensive cutting of mitres additional boards and site delays. Prompt and complete drainage may be difficult to achieve, as these systems do not compensate for deflection in existing substrates. Hot bitumen, special adhesives or mechanical fasteners are typically used to fix boards. Boards are not encapsulated or locked to the substrate. A pattern of continuous joints is inherent in rigid board insulation applications. These joints impart mechanical stress to the roof membrane when the insulation board moves. Services Design Service The initial stages in the design of a FireSmart IRS system are critical if all the relevant design criteria are met. The Icopal Technical Services Department offers a complete design service. Site Survey A comprehensive free site survey is carried out and a detailed report is produced for each individual project, providing all the relevant data to produce a successful design. Design Layout Using the latest CAD technology, design drawings are produced. Calculations for U value and condensation risks are carried out Technical Data Dimensions Thickness where applicable, along with the maximum depth. The reassurance of quality installation by approved contractors systems can only be installed by approved professional contractors, qualified through training, experience and business solidity. This is your assurance of quality workmanship and adherence to relevant regulations and codes of practice. For our Technical Services team please call 0161 865 4444 or email technical.uk@icopal.com Board Size Thermal Stresses Re-roofability Because of its relatively high density FireSmart IRS acts as a heat sink i.e. a slow release of heat. This Thermal Inertia or mass effect, reduces extreme temperature fluctuations and the resulting thermal stresses which cause membrane fatigue failure. FireSmart IRS is highly resistant to damage from moisture and mechanical damage and thereafter will provide an ideal substrate with membrane replacement. Because of the very low thermal conductivity and low density of most rigid board insulation, rooftop temperature fluctuations are greater, causing thermally induced stress on the roof membrane. Most rigid boards are permanently damaged when exposed to water and would need to be replaced during refurbishment. IRS Insulation Board 20mm - 400mm 1200 x 600mm Examples of Achievable Falls 20mm over 1200mm > 1:60 30mm over 1200mm > 1:40 Thermal Performance Compressive Strength Compressive strength 2070kN/m 2 of FireSmart IRS Screed Coverage Rate Bag Size 25kg. Average Coverage Per Bag 0.75m 2 Dependant on System Thickness Stable Insulation Value FireSmart IRS does not contain any HCFCs or other blowing agents to dissipate with time. Therefore, the thermal efficiency does not reduce over time. Some rigid board insulations contain blowing agents that provide high thermal conductivity values initially. Over time, air will diffuse into the cells reducing the thermal conductivity (long term ageing). Thermal Conductivity: IRS Insulation Board value = 0.038 W/m 2 K Screed value = 0.160 W/m 2 K U Value Plywood Deck Concrete Deck W/m 2 K IRS Insulation Minimum System IRS Insulation Minimum System thickness thickness thickness thickness mm mm mm mm 8 Environmentally Safe At the time of re-roofing, the insulation system remains in place, thus not contributing to solid waste disposal problems. FireSmart IRS does not contain components harmful to the Ozone Layer. At the time of re-roofing, rigid boards are usually removed and disposed of in solid waste sites. 0.45 60 89 80 109 0.35 90 119 100 129 0.25 130 159 150 179 0.20 170 199 190 219 9
Case Studies Laying of Waterproofing Base Sheet. St Martin s Junior School, Fitton Hill, Oldham. St Martin s Junior School, Fitton Hill, Oldham Built in the 1960 s the existing roof was constructed of woodwool slabs on a timber beam structure with a 3 layer membrane and was in a very poor condition due to years of inefficient drainage that had led to ponding. The appliance of the screed system provided a uniform fall over the existing deck deviations and to areas of temporary repair where existing rooflights were removed. Backfalls and areas of ponding were easily rectified. The contractors were very impressed by the finish of the roof and the lack of disruption during installation. They were able to maintain the integrity of the existing roof whilst applying the new one. was extremely quick to install as the whole process was completed in 12 days. This project would have normally taken 5 weeks using a conventional rigid board tapered system and produced labour and materials savings of almost 30%. The Drury Inn, San Antonio, Texas The Drury Inn is housed in the former San Antonio City Public Building, an historical landmark on the national register. Constructed in 1921 it was converted to a hotel in the late 1980s. The hotel owners decided that a new roof was required as the existing coal tar pitch roof had deteriorated badly and the slope needed to be modified. On this job the lightweight insulating concrete had to be pumped straight up 110 feet to the top of the penthouse roof and numerous rooftop penetrations had to be planned. After a normal curing time, application of the SBS modified membrane was completed. The system has been proven through successful in place performance records of over thirty years in some of the harshest weather conditions. The system not only met the owner s performance needs, but their aesthetic requirements as well. Visibility from the rooftop pool and surrounding high rise buildings made the finished appearance of the roof important. Lutheran Bible Institute, Washington This was a classic re-roofing situation where an old, leaky roof had to be replaced whilst the building was still occupied. The was poured onto the existing roof without affecting the integrity of the assembly; there were no problems with the weight loads. Pouring the screed directly over the existing coal tar roof saved the dust, debris and noise of a complete tear off operation and also saved considerable demolition and labour costs. Lutheran Bible Institute, Washington, USA. The Drury Inn, San Antonio, Texas, USA. 10 11