Overview of Compressed Insulated Metal Roof & Cladding Systems
The MRC Africa has vast experience in installing, upgrading or refurbishing compressed insulated metal roof & cladding systems. The compressed insulated metal roof system is a standard metal roof system utilised throughout southern Africa, comprising of galvanised or coated steel straining wire set out at 300 – 350mm centres installed over purlin, with a foiled faced insulation blanket compressed between the straining wire and the metal roof sheeting.
There are a range of insulations that can be used between the roof sheeting and the purlin to suit the thermal, fire and acoustic requirements of the building project.
Compressed insulated metal roof systems need to be carefully considered when specifying the metal roof systems installed above them, along with dramatic decreases in expected thermal performance or R-Values.
Please note: Should the metal roof system leak it will invalidate the guarantees provided by the manufacturers and supplier of bulk density insulation blanket and its thermal, fire and acoustic performance.
Compressed insulated metal roof systems – Pierced Fix Roof Systems
Compressed insulated metal roof systems that use a pierced fix metal roof system should only be installed if the roof pitch is above 7.5 degrees and butyl seal type sealants are used on the side and end laps of the metal roof system.
The insulation thickness when compressed between the steel straining wire and the pierced fix metal roof system can lead to structural integrity issues, therefore the maximum bulk density insulation blanket thickness should be no more than 175mm.
Please note: Compressing the insulation WITHOUT A SPACER SYSTEM between the pierced fix roof system and the straining wire reduces the stated uncompressed thermal performance or R-Value by up to 72%.
Compressed insulated metal roof systems – Concealed Fix Roof Systems
Compressed insulated metal roof systems that use a concealed fix metal roof system should only be installed if the roof pitch is above 2.5 degrees with no penetrations.
The insulation thickness when compressed between the steel straining wire and the concealed fix metal roof system can lead to structural integrity issues between the concealed fix roof sheeting and the engagement with the clip, therefore the maximum bulk density insulation blanket thickness should be no more than 75mm.
Please note: Compressing the insulation WITHOUT A SPACER SYSTEM between the concealed fix roof system and the straining wire reduces the stated uncompressed thermal performance or R-Value by up to 72%.
The other area of concern is the engagement between the concealed fix roof sheeting and the clip with the compressed insulation around the clip putting additional pressure on the underside of the metal roof sheet.
MRC Africa’s installed insulated metal roof systems are backed with the unrivalled single source Guardian™ System Warranty which covers materials, installation & maintenance for the term of the built up metal roofing and cladding system.
Key Features of Compressed Insulated Metal Roof & Cladding Systems
- Full range of aluminium and steel ‘Secret or Concealed’ & Pierced Fix roof and cladding systems
- R-Value thermal performance dramatically reduced by up to 72%
- Economic and quick to install
- LPCB non-combustible rock and glass mineral wool used in compressed metal roof systems have the advantage of offering high levels of fire resistance and potentially lower insurance premiums
- Backed with the up to 20 year ‘Guardian’ System Warranty
Applications of Compressed Insulated Metal Roof & Cladding Systems
Compressed insulated metal roof systems have been used throughout southern Africa for over 20 years providing an economic solution for commercial, industrial and retail property.
With the new south african government standards, SANS 10400 XA legislation, the search for energy efficient metal roofing & cladding systems has certainly begun. MRC Africa has been supplying, installing and maintaining such built up metal roof systems as a thermally efficient to alternative to compressed insulated metal roof systems.
- Industrial applications such as Workshops, Factories, Food Processing Facilities and Automobile Assembly Property.
- Commercial and Retail space such as Shopping Malls and Offices.
- Governmental, Educational, Prison & Transportation Property such as Airports, Schools, Universities, Train Stations and High Security Property.
Technical Data of Compressed Insulated Metal Roof & Cladding Systems
Straining Wire Insulation Support System
- 1.6mm galvanised or coated steel wire perpendicularly secured to the purlins at between 300 – 400mm centres
Thermal Insulation for Compressed Insulated Metal Roof Systems
- Full range of insulation types & thicknesses available
- Facings include silver foil, white & black
- Fire Classification Class 1 (non-combustible)
Please note that insulation compressed between purlins & roof sheets will lose up to 72% of the proclaimed R-Value, a constant cavity thickness provided by a Built Up Metal Roof System does NOT compromise the R-Value.
The table below provides the R-Values that can be achieved using a compressed insulated metal roof system.
Weight of a Typical Compressed Insulated Metal Roof System based on purlins at 1800mm centres
- 1.6mm wire at 300mm centres 0.5 kg / m2
- 135mm roll out insulation 1.7 kg / m2
- 0.55mm Secret Fix / Pierced Fix Roof 6.0 kg / m2
Total Weight 8.2 kg / m2
Alternative Compressed Insulated Metal Roof Sheet Options to Consider
- 0.8mm Aluminum Roof System 4.0 kg / m2
- 0.8mm Steel Roof System 9.0 kg / m2
Compressed Insulated Metal Roof System Warranty
- Up to 20 year, single source Guardian™ System Warranty covers Materials, Workmanship & Maintenance
Guarantees & Warranties of a Compressed Insulated Metal Roof & Cladding Systems
MRC Africa’s up to 20 year ‘Guardian’ System Warranty cuts through the myth & mystic of product guarantees and workmanship warranties issued by the construction industry.
Traditionally a product guarantee would be issued by the manufacturer and the workmanship warranty would be issued by the installer of the over-roofing system. Two separate pieces of paper, with differing length of terms and when put alongside each other, never answered the question of who will pay for the materials and works such the over-roofing system fail.
‘Guardian’ System Warranty is an unrivalled new era of warranty that covers Materials, Workmanship & Maintenance. The length of term for each element matches and is issued as a single source, transferrable warranty for the life of the guarantee of the compressed insulated metal roof system.
MRC Africa challenges the construction industry to ensure that the workmanship warranty issued by contractors matches the length of term of the supplied built up metal roof & cladding system, thereby ensuring high quality installations with designed and tested compressed insulated metal roof & cladding systems.