Prefabricated roof element

Ruukki's prefabricated roof elements are particularly suited for buildings in which the roof has to be put in quickly. On account of the large size of the elements, the roof can be assembled swiftly and without the need for further work on the internal or external surfaces.

Due to the adaptability of the elements, prefabricated roof element can be used in roofs that require special properties such as efficient thermal insulation, sound absorption or fire resistance.

The elements can be tailor-made to meet customers' specific needs.  

Applications:

  • Airports
  • Sport halls
  • Industrial units
  • Transport terminals

The information on our website is accurate to the best of our knowledge and understanding. Although every effort has been made to ensure accuracy, the company cannot accept any responsibility for any direct or indirect damages resulting from possible errors or incorrect application of the information of this publication. We reserve the right to make changes.

Copyright © 2016 Ruukki Construction. All Rights Reserved.

    Technical information
    Dimensions  
    Standard width 2400 mm 
    Maximum length for standard width 14000 mm
    Standard height 200, 225, 250, 275, 300, 350, 400 mm





    Structure & U-values

    Structure



    R1 Prefabricated-roof-elements-design-R-1
    • PVC membrane
    • Construction plywood 15 mm
    • LPT-C purlins + mineral wool (200 - 400 mm)
    • Vapour control layer
    • Plywood or profiled sheet
      • Standard coating/colour for sheet is PE/RR20 in all designs

    R2 Prefabricated-roof-elements-design-R-2
    • PVC membrane 
    • Construction plywood 15 mm 
    • LPT-C purlins + thermal insulation (200 - 400 mm) 
    • Vapour control layer 
    • Plywood or gypsum board 
    • Soft insulation 30 - 50 mm
    • Profiled sheet, perforated if necessary

    R-T Prefabricated-roof-elements-design-R-T
    • PVC membrane or felt covering 
    • Construction plywood 15 mm 
    • Ventilation gap 75 - 100 mm
      • hat purlins k900
    • Wind shield board (plywood) 9 mm
    • LPT-C purlins + mineral wool (200 - 400 mm) 
    • Vapour control layer 
    • Plywood or profiled sheet


    U-values



    R1-4r Prefabricated-roof-elements-design-R-1
    • PVC membrane
    • Construction plywood 15 mm
    • LPT-C purlins + mineral wool (200 - 400 mm), 0,034 W/mK
    • Vapour control layer
    • Plywood or profiled sheet
      • Standard coating/colour for sheet is PE/RR20 in all designs



    Roof structure R1 Lower surface Perforation U-value (W/m2K)
    LPT-C20015 Profile  8-rows  0.23
    LPT-C20020 Profile  8-rows  0.24
    LPT-C22515 Profile  8-rows  0.21
    LPT-C22520 Profile  8-rows  0.22
    LPT-C25015 Profile  8-rows  0.20
    LPT-C25020 Profile  8-rows  0.21
    LPT-C27515 Profile  8-rows  0.19
    LPT-C27520  Profile   8-rows  0.20
    LPT-C30015  Profile    8-rows  0.18
    LPT-C30020   Profile     8-rows  0.19
    LPT-C35015   Profile      8-rows  0.17
    LPT-C40015  Profile   8-rows  0.16
    LPT-C40020  Profile    8-rows  0.17

    U-values by standard ISO EN 6946:2007 and EN 10211:2007. U-values need to be checked for each project according to project specification and chosen structural system, such as purlin specified in element.

    Sound insulation

    Sound insulation

    Rw values are theoretical values

     
    R1b Prefabricated-roof-elements-design-R-1
    • Single-ply PVC membrance
    • Construction plywood 15 mm
    • LTP purlins 200 - 400 mm (k600) + thermal insulation
    • Plastic VCL
    • Sheet 0.5 mm T20-72-1090


    Purlin Rw values
    LPT-C200 48 dB
    LPT-C225 48 dB
    LPT-C250
    49 dB
    LPT-C275 50 dB
    LPT-C300 50 dB 
    LPT-C350 51 dB 
    LPT-C400  52 dB 
       

    R2 Prefabricated-roof-elements-design-R-1
    • Single-ply PVC membrance
    • Construction plywood 15 mm
    • LTP purlins 200 - 400 mm (k600) + thermal insulation
    • Plastic VCL
    • Plywood 9 mm
    • Thermal insulation 50 mm
    • Perforated sheet 0.5 mm: T20-30W-1090 3 mm 15%



    Purlin Rw values
    LPT-C200 47 dB
    LPT-C225 47 dB
    LPT-C250
    47 dB
    LPT-C275 47 dB
    LPT-C300 47 dB
    LPT-C350 47 dB
    LPT-C400  48 dB
       

    Sound absorption coefficients for the lower surface

    Example of structure type R2
    Prefabricated-roof-elements-design-R-2 
    • Single-ply PVC membrance
    • Construction plywood 15 mm
    • LTP purlins 200 - 400 mm (k600) + thermal insulation
    • Plastic VCL
    • Plywood 9 mm
    • Thermal insulation 50...100 mm
    • Dust cover
    • Perforated sheet 0.5 mm: T20-30W-1090 3 mm 15%
    This structure meets the requirements of absorption class B or A (EN ISO 11654) depending on the thickness and quality of the bottom insulation. 
    Fire resistance

    Fire resistance

    Ruukki's prefabricated roof elements do not incorporate combustible materials, with the exception of the moisture barrier and any plywood layers. 
    The fire class of the PVC membrane is BROOF (t2). When using the PVC membrane on plywood, the roof must be divided into sections, each 2400 m2 in size (E1; 8.4.3).

    The lower surface's fire class requirements are checked according to the building's fire class and the purpose of use of each respective space. For example, in a P2 class building, the surface fire class must in most cases be B-s1, d0, which effectively means that there must be a gypsum board or steel sheet installed on the lower surface. Where a perforated steel sheet is used for the lower surface and combustible sound absorption material in to be used, the appropriateness of the structure must be ensured on a case-by-case basis.

    When fire class requirements are set for the elements' fire resistance, the load-bearing ability during a fire must be checked when dimensioning the purlins.

    The requirement for the R15 class can usually be met with a basic structure featuring a steel sheet or plywood on the lower surface, provided that this is otherwise appropriate for the building. The R30 class requirements can be met with a structure which has a gypsum board (GN13) on the lower surface between the steel sheet covering and the purlins. For the R60 class, two fire-resistant gypsum boards (GF15) are required on the lower surface.

    REI15 structure

    Prefabricated-roof-elements-design-R-1 
    • PVC membrane 
    • Construction plywood 15 mm 
    • LPT-C purlins (200...400) k 600 
       - Rockwool UNS35 or A-Batts
    • Vapour control layer 
    • Profiled sheet T15-115-1134  t=0.5

     

    Prefabricated-roof-elements-design-R-2 
    • PVC membrane 
    • Construction plywood 15 mm 
    • LPT-C purlins (200...400) k 600 
       - Rockwool UNS35 or A-Batts
    • Vapour control layer 
    • Gypsum board GN13
    • Rockwool 50 mm
       - UNS35 or A-Batts
    • Profiled sheet, perforated if necessary, T15-115-1134  t=0.5

     

    Order & delivery
    Ruukki designs and delivers prefabricated roof elements based on customer's specifications for the project.