Polycarbonate & GRP

GENERAL

Polycarbonate is one of the newer plastics to be used in the construction industry around the world. MODEK has been closely involved in the distribution and manufacture of profiled PC roof sheets during the past 10 years in South Africa.

The highest grade POLYCARBONATE polymer available from the leading manufacturers in the world, is used by MODEK. Modern co-extrusion technology is used in the manufacture of MODEK PC sheets, ensuring a high product quality and allowing for any transportable length of sheet to be made.

A layer of highly UV stabilised POLYCARBONATE is co-extruded on the weathering side of all MODEK PC roof sheets. This layer will not crack or delaminate, and ensures years of clear performance in the harsh South African climate.

A range of colours is manufactured with the standards being clear, white (opal 50) and bronze. Silver (Heat Stop), blue and green are also available subject to order quantity.

All the generally used profile shapes in South Africa, to match those of other non-translucent roofing and cladding sheets, are manufactured by MODEK in any transportable length.

New or additional roofing profiles can be manufactured by MODEK, but it must be noted that the time and cost incurred is considerable. Please contact MODEK’S Technical Department for more detailed information.

NOMINAL THICKNESS

The internationally accepted unit of measurement, as used by MODEK, for PC sheeting is the nominal thickness of the sheet.

This nominal thickness should be established by representative measurements (by vernier or micrometer) at various points across the full width of the sheet.

Owing to the inherent variances of tolerance which are experienced when profiling a thermoplastic extrusion, it will be found that the actual thickness will vary slightly from one point to another on the sheet.

MODEK manufactures two nominal thickness specifications:

• 1.25 mm Nominal Thickness
• 1.00 mm Nominal Thickness

A layer of UV protection PC is co-extruded on the weathering side of all MODEK PC roof sheets.

1.25 mm Nominal Thickness is deemed to be the Standard Weight Specification for all industrial installations. This specification will meet the rigorous conditions found in an industrial environment – particularly that of deflection under load (positive and negative), handling on site, spanning capabilities and general robustness of profile.

1.00 mm Nominal Thickness is manufactured as a light weight PC sheet to be used mainly in those applications where exposure to wind is less, spanning requirements are less than normal, and generally lighter domestic-type applications.

The 1.00 mm nominal thickness products are restricted to certain profiles only. Refer to the profile list for details.

LIGHT AND SOLAR ENERGY TRANSMISSION

Different applications using translucent MODEK PC sheeting call for varying levels of light transmission. With different colours these levels change.

Not only does the natural (or visible) light level vary, but the amount of solar energy (heat) also varies.

Polycarbonate is a thermoplastic with a high degree of clarity. Therefore the direct transmission of solar energy is considerably higher than that of a diffused panel. Consideration for the appropriate colour should therefore be carefully weighed up.

The diagram below depicts the approximate transmission of the various wavelengths of the light spectrum for a clear PC sheet.

More than 70 % of the heating effect of the sun is carried between 350 and 800 nanometres (generally, the visible light spectrum) and we can see that these wavelengths are generously transmitted through a clear MODEK PC sheet – more than 85 %.

Why does heat build up in a room?

As illustrated, a high percentage of the visible short wave radiation has been transmitted through a MODEK PC clear sheet.

This radiation is absorbed by surfaces inside the room, and these surfaces become heat radiators. The heat emitted from these “radiators” is long wave radiation which is not so readily transmitted out of the room through the MODEK sheet. The result is that the trapped heat builds up in the room. This is also known as the “greenhouse effect”.

An effective method of combating heat build-up in a room is to have good through ventilation. This can also be improved by selecting the most appropriate MODEK PC roof sheet.

The table below shows the various percentages of transmitted light and solar energy, and also that amount of light and solar energy which is reflected and absorbed by the different coloured MODEK PC sheets.

ColorQUEST Colorimeter Test Results
MODEK PC Translucent Roof Sheets

Notes:

• Shading coefficients are used for comparing solar heat transmission properties of different glazing materials to that of clear float glass 3 mm to 4 mm thick, the glass being given a value of 1. To be used for comparative purposes only.
• For practical purposes, MODEK PC sheets do not transmit harmful UV rays.

Should there be any further requirements regarding the light and solar energy transmission of MODEK PC roof sheets, contact MODEK’S Technical Department.

MODEK HEAT STOP

MODEK Heat Stop is an innovative development in polycarbonate translucent roof sheeting. This product effectively eliminates 60% of the radiated heat of the sun, resulting in a cool shaded environment.

MODEK Heat Stop is a polycarbonate profiled extrusion, manufactured in South Africa, which has a co-extruded layer of UV stabilised surface protection on the weather side. Microscopic reflective particles are incorporated in the core material which create the silver colour and the reflective qualities of the product.

If an application for a translucent roof sheet or skylight requires a minimum heat build-up under the natural light panel – MODEK offers a polycarbonate solution. It should be remembered, however, that a lower level of light transmission is achieved with MODEK Heat Stop. The appropriate surface area of translucent roof sheets must therefore be used to achieve the required interior light levels.

MODEK Heat Stop offers the following properties:

• All the excellent physical properties of polycarbonate.
• UV surface protection on weather side.
• Exciting new colour – silver.
• 20 % light transmission.
• It is available in 1 mm and 1.25 mm profiles:
  IBR
  Corrugated
  Nurib
  Grecca
• Price – the same as the normal tint price.

ColorQUEST Colorimeter Test results

Notes:

• Shading coefficients are used for comparing solar heat transmission properties of different glazing materials to that of clear float glass 3 mm to 4 mm thick, the glass being given a value of 1. To be used for comparative purposes only.
• For practical purposes MODEK Heat Stop does not transmit harmful UV rays.

WEATHERABILITY

MODEK PC roof sheeting is manufactured using modern co-extrusion technology to create a highly UV stabilised weathering surface on the sheet.

This UV layer will not crack or delaminate, and ensures years of trouble-free performance in the harsh South African weather conditions.

As with almost all plastics, UV attack from the sun will, over a period of time, adversely affect MODEK PC roof sheets. This process is called photodegradation.

What occurs during this process is the following:

The aggressive short wavelength UV rays are absorbed into the polymer. They “excite” the chemical molecular bonds, causing them to separate, resulting in a slight yellowing and a reduction of physical properties such as tensile strength and impact resistance.

This process is significantly reduced in the MODEK PC sheet because of the excellent protection offered by the UV co-extruded layer which incorporates UV stabilisers and UV absorbers. Over a prolonged period, a slight yellowing or hazing will be detected in a MODEK PC sheet.

With outside exposure in normal conditions in South Africa, it is expected that a clear MODEK PC sheet with UV protection will not increase in yellowness more than 9 yellowness index units within ten years from date of sale.

The determination of the yellowing index will be made on samples subjected to pre-test cleaning and conditioning according to MODEK’s test procedures, and the yellowness index shall be determined according to ASTM D-1925-70 as measured with Hunter Colour-Quest colour Spectrophotometer.

A MODEK PC sheet will retain virtually all its physical properties, and remain structurally sound over this period of time, under normal conditions.

CORROSION AND CHEMICAL RESISTANCE

MODEK PC sheets will resist chemical attack and corrosion in most industrial and marine environments.

Tests have found the following:

• MODEK PC is highly resistant to corrosion and high concentrations of mineral acids, many organic acids, oxidising and reducing agents, neutral and acid salt solutions, many oils and fats, saturated aliphatic and cyclo-aliphatic hydrocarbons and alcohols.
• MODEK PC is not resistant to strong acids and alkalis, methyl alcohol, aromatic hydrocarbons and chlorinated hydrocarbons nor to lengthy immersion in hot water.
• MODEK PC must not be used in conjunction with plasticised PVC. This will result in stress corrosion cracking and cause damage to the MODEK PC sheet.
• MODEK PC sheets are ideal for coastal applications.

The resistance to chemical attack varies with a wide range of chemicals, detergents, polishes and cleaning agents. This resistance chart refers to certain chemicals and the reaction of PC under certain conditions. Please refer to MODEK’S Technical Department should you have a query.

Flashing

GENERAL INFORMATION

Accessories are produced on sophisticated hydraulic press brake facilities to a high degree of accuracy. The products illustrated are an indication of a wide range of standard accessories available from CSI. The production process allows for a lot of flexibility so our technical staff should be contacted should you have special requirements.

MATERIAL OPTIONS

Accessories can be ordered in galvanised sheet and Colour Coated Chromadek. Galvanised thickness ranges from from 0,4mm to 1,60mm. Chromadek is normally supplied with a silicone polyester paint system on the outside and a standard Dove Grey backing on the reverse side of the sheets.

SIZES

Accessories can be ordered in standard lengths of 3,0m and special lengths up to 6 metres.

TOLERANCES

Typical dimensional tolerances are ±2,0mm

Colour Range

Aloe Green	Azure Blue	Jasper
Buffalo Brown	Charcoal Grey	Heritage Red
Dark Dolphin	Dove Grey	Colonial Green
Fish Eagle White	Gemsbok Sand	African Blue
Kalahari Red	Kingfisher Blue	African White
Sandstone Beige	Traffic Green	Off White
Shale Grey	Armour Grey	African Cream
Cape Charcoal	Dune	Amazing White
Ore Grey	African Charcoal	Garden Route Green
Cape White	Almond Beige	Loft
Bushland	Pale Eucalypt	Deep Ocean
Sahara Sands

Bullnosing

CRANKING OF PROFILED SHEETING

Cranking of a profiled sheet incorporates lateral rib indentations pressed in at uniform distances which vary according to the radius requirements.

Cranked sheets can be supplied in standard radii as follows:

STANDARD CRANK (686 & 760)

Normally with the narrow flute uppermost and the bend away from the angular inclination.

REVERSE CRANK (686 & 760)

Normally with the narrow flute downwards and the bend into the narrow flute. Cranks can be at the end/ends of a sheet or at any position along the length.

Note: All profiles can be cranked in Full Hard and commercial quality material but only to a minimum radius of 300mm.

889 – Industrial Seven

GENERAL INFORMATION

889 Industrial Seven is an angular trapezoidal fluted profile sheet used preferably for aluminium, BHP Zincalume® and Colorbond® steel, but on request is also available in galvanised and chromadek with virtually the same characteristics as IBR but having an effective cover of 889mm.

• The general shape and appearance of the trapezoidal flutes ensure that 889 Industrial Seven is totally acceptable for use as roof and wall cladding. The deep and broad flutes of the 889 Industrial Seven type sheeting ensures excellent drainage characteristics, whch makes it an ideal sheet for roofing applications.
• 889 Industrial Seven offers optimum strength to weight and is designed to provide the most advantageous load/span characteristics consistent with economy.
• 889 Industrial Seven offer the end user the option of having strengthening ribs in the sheet which help to remove oil canning from the broad flute.
• 889 Industrial Seven can be factory cranked, curved and bullnosed to a wide range of radii (see Bullnosing). For further details contact our Technical Department.

MATERIAL OPTIONS

Note: If galvanised or chromadek material is specified please contact our technical department for technical data

LENGTHS & ROOF PITCH

889 can be ordered in any length up to 18 metres as per the customers requirements. The maximum length for road transportation is 13,2 metres and lengths over 13,2 metres require special transport arrangements. The minimum roof pitch when using 889 is 5° provided the roof slope is less than 30 metres. For roof slopes over 30 metres a minimum roof pitch of 7,5° is recommended.

TOLERANCES

Length variation of ±5,0mm and width tolerances of ±3,0 mm is permissible.

PURLIN SPACINGS*

Purlin Spacings are dependant on both downward loading and negative suction loading caused by wind. Your engineer should be consulted to calculate your load (kn/m²) for your particular application. A broad guideline for Purlin Spacings is shown in the table below.

889 COVERAGE TABLE
(Full width 737mm / Covering with 686mm)

760 – Widek or Widespan

GENERAL INFORMATION

760 – Widek is also an angular trapezoidal fluted sheet and is similar in appearance to IBR profiled sheeting, the difference being the cover width of the sheet, and the depth of the flutes. IBR sheeting has a cover width of 686mm whereas 760 has a cover width of 760mm. The depth of the flutes on IBR sheeting are normally 36,5mm and the depth of 760 is 28,5mm. Using this type of sheeting has some cost saving advantages.

• The 760 profile giving a better cover width means a saving of ±10% on sheeting purchased thus a cost saving.
• To achieve the same coverage less sheets are required to be erected, thus saving time and labour.
• The advantage of using 760 in place of the sinusoidal corrugated profile is in its strength, that is to say the spanning capacity of 760 are greater than the corrugated profile thus requiring less purlins resulting in a cost saving.
• 760 Widek can be factory cranked, curved and bullnosed to a wide range of radii (see Bullnosing).

MATERIAL OPTIONS

Note 1 –

762 corrugated, IBR 686 and Widek 760 are supplied in a Z200 spelter
Note 2 –

Full Hard can be ordered in a Z275 and Z250 spelter. We offer 0,6mm and 0,8mm material in commercial quality, and 0,4mm and 0,6mm in Full Hard.
Note 3 –

Available in Mittal’s standard chromadek colour coated range. Special colours are available on request. Please contact our sales staff for further details.
Note 4 –

We profile certain grades of aluminium and stainless steel. Please contact our sales staff if you require further details.

LENGTHS & ROOF PITCH

760 can be ordered in any length up to 18 metres as per the customers requirements. The maximum length for road transportation is 13.2 metres and lengths over 13.2 metres require special transport arrangements. The minimum roof pitch when using 760 is 7,5°.

TOLERANCES

Length variation of 5,0mm and width tolerance of 3,0mm is permissible.

PURLIN SPACINGS

Purlin Spacings are dependant on both downward loading and negative suction loading caused by wind. Your engineer should be consulted to calculate your load (kn/m²) for your particular application. A broad guideline for Purlin Spacings is shown in the table below.

Double Span refers to a length of sheet being continuously supported over 3 or more purlins.

760 COVERAGE TABLE
(Full width 737mm / Covering with 686mm)

700 – Sheeting

GENERAL INFORMATION

700 – concealed fix is an angular interlocking standing seam trapezoidal rib profile roll formed currently on static mills in our Johannesburg and Cape Town operations. 700 has a nett cover width of 700 mm. The depths of the flutes are 41.5 mm and include capillary breaks. Along the edge of the male rib, spurs at 300 mm centres ensure positive interlocking of side laps. Two stiffening ribs are incorporated in each pan.

MATERIAL OPTIONS

PURLIN SPACING

Purlin spacings are dependent on both downward loading and negative suction loading caused by the wind. Your engineer should be consulted to calculate your load (kn/m2) for your particular application. A broad guideline for purlin spacings is shown in the table below. Double span refers to a length of sheet being continuously supported over 3 or more purlins.

CLIPPING SYSTEM & FASTENER

This clipping profile is fastened to the purlin by means of a sheet clip. Sheets are locked onto the clips and therefore not perforated. Spurs at 300 mm centres on male rib ensure positive interlocking of side laps.

CRANKING

700 sheets may be cranked and bullnosed but not reverse bullnosed. Minimum radius is 450mm. Minimum radises for springing or draping is 36 metres.

LENGTHS AND ROOF PITCH

700 can be ordered in any length up to 27 metres as per customer requirements. The maximum length for road transportation is 13,2 metres. Special transportation arrangements to be discussed and arranged for the longer lengths. The minimum roof pitch when using 700 is 2 degrees.

700 COVERAGE TABLE
(Full width 728mm / Covering width 700mm)

686 – IBR Profile

GENERAL INFORMATION

686 “IBR” is an angular trapezoidal fluted profile sheet. Its bold appearance makes it both attractive and practical. Since IBR was introduced to the South African market in 1958, it has become the most popular sheeting used in the construction of commercial and industrial buildings. IBR is an abbreviation for Inverted Box Rib. The number “686” signifies the sheets’ effective cover width.

• The general shape and appearance of the trapezoidal flutes ensure that 686 “IBR” is totally acceptable for use as roof and wall cladding. The deep and broad flutes of the 686 “IBR” Type sheeting ensures excellent drainage characteristics, another characteristic that makes it an ideal sheet for roofing applications.
• 686 “IBR” offers optimum strength to weight and is designed to provide the most advantageous load/span characteristics consistent with economy.
• 686 “IBR” offer the end user the option of having strengthening ribs in the sheet which help to remove oil canning from the broad flute.
• 686 “IBR” can be factory cranked, curved and bullnosed to a wide range of radii (see Bullnosing). For further details contact our Technical Department.

MATERIAL OPTIONS

Note 1 -762 corrugated, IBR 686 and Widedek 760 are supplied in a Z200 spelter
Note 2 -Full Hard can be ordered in a Z275 and Z250 spelter. We offer 0,6mm and 0,8mm material in commercial quality, and 0,4mm and 0,6mm in Full Hard.
Note 3 -Available in Mittal’s standard chromadek colour coated range. Special colours are available on request. Please contact our sales staff for further details.
Note 4 -We profile certain grades of aluminium and stainless steel. Please contact our sales staff if you require further details.

610 / 762 Corrugated Profile

GENERAL INFORMATION

610/762 Corrugated Profile. Both are sinusoidal profile sheets and can be used as roofing and cladding material. With its origins dating back to the Victorian era, it’s probably the most commonly known sheeting profile used in the world today.

• There are two sizes of corrugated sheeting on the market, 8½ Corrugated and 10½ Corrugated. The numbers 8½ and 10½ refer to the number of corrugations across the width of the profiled sheet.
• The two types of corrugated sheeting have different cover widths. 610 has a cover width of 610mm and 762 has a cover width of 762mm.
• The fact that the corrugated profiled sheeting has been around since before the turn of the century proves that this easy to use and effective method of roofing and wall cladding is here to stay.
• Corrugated 610/762 can be factory cranked to a curve and bullnosed to a wide range of radii (see Bullnosing).

MATERIAL OPTIONS

Note 1 – 762 corrugated, IBR 686 and Widedek 760 is supplied in a Z200 spelter
Note 2 – Full Hard can be ordered in a Z275 and Z250 spelter. We offer 0,6mm and 0,8mm material in commercial quality, and 0,4mm and 0,6mm in Full Hard.
Note 3 – Available in Mittal’s standard chromadek colour coated range. Special colours are available on request. Please contact our sales staff for further details.
Note 4 – We profile certain grades of aluminium and stainless steel. Please contact our sales staff if you require further details.

LENGTHS & ROOF PITCH

Corrugated sheeting can be ordered in any length up to 18 metres with the proviso that lengths over 13,2 metres require special transport arrangements. Corrugated sheeting is not suitable for roof pitches below 15º. If roof slopes longer than 15 metres are not recommended.

TOLERANCES

Length, width and edge wave tolerance of ±5,0 mm is permissible.

PURLIN SPACINGS

Purlin Spacings are dependent on both downward loading and negative suction loading caused by wind. Your engineer should be consulted to calculate your load (kn/m²) for your particular application. A broad guideline for Purlin Spacings is shown in the table below.

Double Span refers to a length of corrugated sheet being continuously supported over 3 or more purlins.

Covering width will change if double side lap is used as opposed to a single side lap. 762 covering width will reduce to 686mm and 610 covering width will reduce to 535mm.

COVERAGE TABLE FOR SINGLE LAPS

(762 Full width 838mm / Covering width 762mm)
(610 Full width 710mm / Covering width 610mm)