Flat roofs
Thermal isolation: mineral wool - polystyrene
MINERAL WOOL
For flat roof there is used materials from mineral felt. It is produced from mineral fibres to which agglutinant is added and after curing and cutting products in form of boards are obtained. For hydro-isolated cover sheets of impassable roofs are recommended cohesive underlay of compressive strength of 40 kPa when 10% compression (40kPa = 0,04N/mm2 = 4 t/m2). All the thermal isolation materials made from mineral felt supplied for flat roofs meet this requirement.
DACHROCK - Heavy middle board designed for thermal, sound and fire insulation of roof construction. Boards are in the entire section waterproof and they are volume consistent. They are suitable either for bonded of mechanically anchored constructions of roofing cover. In middle structure is the upper ply thermal isolation.
Thermal conductivity coefficient: 0,039 Wm-1K
Supplied sizes: (H x W): 1000 x 500 mm, 2000 x 1200 mm
Supplied thickness: 40 - 140 mm
SPODROCK - Rigid roofing board designed to be a base layer for double-layer thermal isolation of roofing cover.
Thermal conductivity coefficient: 0,039 Wm-1K
Supplied sizes: (H x W): 1000 x 500 mm, 2000 x 1200 mm
Supplied thickness: 40 - 140 mm
Assortment of isolation materials from mineral fibres ORSIL contains among others also products convenient for single-sheet isolation of flat roofs. It concerns ORSIL S and ORSIL T boards that provide thermal-isolation layer applied as a base under various types of hydro-isolated covering. By its mechanical parameters meet the requirements for walkway roofs and last but not least they improve parameters of roof structure regarding sound attenuation and fire endurance.
ORSIL S boards are water resistant (hydrophobic through the whole board). The maximum thickness of ORSIL S boards is 120 mm and when bigger thickness of isolation required it is necessary to pile up. For the first layer of ORSIL boards either the ORSIL T or ORSIL S might be used, for the second layer (upper) always ORSIL S.
ORSIL boards are laid spádovou vrstvu nasraz and when boards are double-layered are the layers relayed on gripes.
Another product designed for flat roofs are attic contact wedges T-AK, used for the right solution to connect hydro-isolation of flat roof with attic and vents of roof constructions.
POLYSTYRENE
Foamed Polystyrene Pieces
Foamed Polystyrene
Foamed Polystyrene Pieces
It concerned completed product that consist of thermal insulation from foamed polystyrene, on which is, when produced, laminated by bitumen hydro-isolation sheet. This hydro-isolating sheet, which is of 1080 thickness, it is glued on the board by polyurethane adhesive whereby between hydro-isolation sheet and the surface of the thermal insulation expansive layer created. On both sides of assembled product the foamed hydro-isolation sheet overreach the polystyrene sheet by 80 mm. If the application of this product is correct the foamed bitumen sheet creates hydro-isolation layer of roof sheet. Board from foamed polystyrene is either flat or humped. The flat board equipped by teeth, which minimizes Heat Bridge, can be also delivered. As per request also these assembled products with cross-sections (which help their laying) might also be delivered.
Shape and dimensions of assembled POLYROOF special products
a) classic board 1000 x 1000 mm - nominal thickness: 40 to 500 mm (by 10 mm)
b) double-board 1000 x 2000 mm - nominal thickness: 40 to 500 mm (by 10 mm)
c) single-side grooved board 1000 x 1000 mm thickness from 20 mm in groove as per request. Standard groove angle is multiplied by 0.5%; it is also possible to be 0.1%
d) lamella sheet from 1000 x to 3000 mm
Foamed polystyrene
This approved thermal insulation material is delivered for flat roofs as stabilized and self-extinguishing. Foamed polystyrene that composes thermal insulation of flat roofs should have essential volume weight over 20 kg/m3 - polystyrene with lower volume weight has not only lower compressive strength but also higher porosity and absorbability. Therefore they might be a source of failure of roof covering mostly concerning volume changes of this lighter material.
Requirement for minimal volume weight of foamed polystyrene that creates thermal insulation of flat roofs states not only norm EPS 002/99 passed by Association of manufactures of foamed polystyrene of CZ named Quality Norm of Boards for Flat roof Isolation, but the same requirements of quality this thermal insulation material are reported by foreign directives. Foamed polystyrene supplied in Czech Republic under trade name: PSB-S-20 fails to fulfil quality requirements as its volume weight 15 to 20 kg/m3. If this less expensive polystyrene PSB-S-20 with foamed hydro isolation sheet, from any reason, will be required, it is possible to deliver but with above mentioned condition.
If assembled products: POLYROOF special with teeth required, it is necessary to notice that teeth of 15 mm width is created by polystyrene milling on lengthwise sides of the basic board of 1000 mm width. Therefore the structural width of the product is 985 mm. If teeth will be implemented even on transverse sides of the product, its structural dimension will be diminished to 985 mm or 1985 mm (depend on the product). Teeth are possible to order either on lengthwise sides only or on transverse sides of the product (around the entire product). Teeth are supplied per order only for board (sheet) products.
Per order it is possible to deliver POLYROOF special products with cross-sections either for board products or downflow wedges. Cross-sections are standard designed with pitch of around 125 mm, per order it is possible to accomplish also with other pitch values.
Cross sections on foamed polystyrene products:
- Minimizes stress in thermal isolation material because of its thermal expansivity.
- Minimizes possible residual plastic flow of embedded polystyrene in roof sheet.
- Enables better laying of product on local surface bumps.
- If needed it enables shaping of the product to axils or to bent surfaces of the roof covering.
- Enables better laying in case of sticking on THERM sheets Vapour Retarders (these Vapour Retarders are delivered by some producers of bitumen sheets).
- It Creates space in roof covering for possible expansion of vapour in thermal isolation under first hydro isolation layer.
POLYROOF special
is standardly delivered with thermal isolation from stabilized self-extinguishing expanded polystyrene PSB-S-25 with volume weight 20 to 25 kg/m3 for classical common flat roofs. In case that on flat roof the terrace will be built or on the roof is placed a heavy technological (or other) equipment, we recommend to use these assembling products made from polystyrene PSB-S-35 with volume weight of 30 to 35 kg/m3 that has higher compressive strength (in foreign countries in this case the firmer polystyrene is prescribed). If embedded assembled boards will be POLYROOF special in roof covering loaded by technological (or other) equipment, it is important to attest if in specific case, it is not exceeded the their admissible tensile loading.
When exceeding mostly spot tensile load of polystyrene compression of this thermal isolation might be reached. For these practical needs we recommended to use safe tensile load of polystyrene of value that is of 10% of the value when 10% compression. These values are stated in paragraph below as admissible values.
| Type of foamed polystyrene | PSB-S-25 | PSB-S-35 |
| Volume weight (kg/m3) | 20 to 25 | 30 to 35 |
| Coefficient of thermal conductivity λk (W/mK) characteristic | 0,035 | 0,032 |
| Coefficient of thermal conductivity λk (W/mK) computational *) | 0,037 | 0,034 |
| Compressive strength by 10% compressed (MPa) | 0,14 | 0,22 |
| Compressive strength by 2% compressed (MPa) according DIN | 0,020 to 0,035 | 0,036 to 0,062 |
| Admissible compressive strength | 0,014MPa = 1,4t/m2 | 0,022MPa = 2,2t/m2 |
| Permanent heat stress (°C) | 80 | 80 |
| Volume absorbability (maximum %) | 3,0 | 2,5 |
| Combustibility grade according to ČSN 73 0862 | C1 | C1 |
| Diffusiveness resistant factor µ (-) | 30/70 | 40/100 |
| Note *): Calculated value of Coefficient of thermal conductivity λp (W/mK) is stated here an informative value. For specific materials it is needed to define the value from ČSN 73 0540-3:94 norms. | ||
Foamed hydroisolation sheets
On thermo isolation pieces are foamed hydro-isolation sheets according customers` requirements depending on delivery possibilities of asphalt sheets producers. POLYROOF special products foamed by asphalt sheets are commonly supplied:
| Sheet name | Bitumen type | Type of loading ply | Sheet thickness |
| PARABIT V 60 S 35 | oxidized | glass mat 60 g/m2 | 3,5 mm |
| PARABITGLAS G 200 S 40 | oxidized | glass mat 200 g/m2 | 4,0 mm |
| PARAELAST G S 35 - 25 | modified SBS (-25°C) | glass mat 200 g/m2 | 3,5 mm |
| ROOFSPECIAL G S 35 - 15 | modified SBS (-15°C) | glass mat 200 g/m2 | 3,5 mm |
| ROOFSPECIAL G S 35 - 25 | modified SBS (-25°C) | glass mat 200 g/m2 | 3,5 mm |
Product usage
Assembled thermal isolation POLYROOF special board-products with foamed hydro-isolated sheet are aimed to provide thermal isolation single-layered for unventilated flat roofs. When professionally layered on roof sheet it provides quality thermal isolation and at the same time first hydro-isolation layer. They are used either for new roofs or for reconstructions for additional thermal isolation of flat roofs. If necessary technological principles are complied when laying is possible to them also as thermal isolation of sloped flat roofs with waterproof isolation from asphalt sheets - in this case we recommend to consult their usage with consultant attendance of COLEMAN S.I. Inc.
Assembled thermal isolation single-sided boards POLYROOF special with foamed hydro-isolated sheet form in roof covering of single-layer flat roofs humped layer, thermo-isolation and hydro-isolation layer. As a part of delivery of these products is also their laying plan worked out for your roof. For using these products is therefore important to provide us in advance with following documents:
- Dimensional plan of roof with ground inner dimension of roof and with dimensions of position of roof inflow.
- Height of attic
- Minimal and maximal thickness of thermal isolation
- Minimal required slope of roof in %
- Required type of foamed hydro-isolation sheet
- Type of expanded polystyrene. (e.g. PSB-S-25 stabilized)
- Delivery date
Foamed polystyrene
Foamed polystyrene is characterized by very low thermal conductivity that is virtue of cells structure consisted from a lot of closed polystyrene cells of polyhedrons that contain air that is significant for its low thermal conductivity. With volume weight of EPS 20 kg/m3 and 1 cm thickness has almost the same isolation ability as 20 cm thick wall from massive bricks. Foamed polystyrene belongs to construction materials with very low weight while high strength is kept. Thereby it not overloads engineering construction, reduces lifting and transport costs and facilitates the application. The maximal volume absorbability of common polystyrene is around 4%.
Gathering (sloping) system of flat roofs: is aimed for single-layered roofs either for new buildings or sanitation of existing buildings for required gathering assurance and thermal-specifications projected by designer.
It avoids problems incurred by standing water on flat roofs. When it is correctly used it fully guarantees the inner and outer unwatering of flat roofs. The base of the system is Gathering board from foamed polystyrene PSB - S - 25S (PSB - S - 30,35 S). This board ensure the basic thermal and technical characteristic and arbitrary slope (by 0.5%) of roof.
Advantages:
