Safintra’s concealed fix roof sheeting has attained its position as the preferred system for long-span or low-slope roofs due to its versatility, durability and proven functionality.
These systems are ideal for long length sheets on industrial and commercial buildings, and have also become extremely popular in high-end residential applications – allowing for the construction of eye-catching roofing systems which were never previously possible with traditional pierced fixed profiles and tiles.
Well-designed concealed fix roofing and cladding solutions can handle the most robust of weather conditions with ease and offer superior performance under foot traffic and associated roofing workloads.
One of the main benefits of concealed roof sheeting is that the sheets are secured to the purlin with a clip system from underneath and are not pierced with any fasteners. The clips which are required to fix the sheets to the purlins serve two purposes:
1. They sidestep the need for holes in the sheet (which prevents the possibility of leakage through perforation).
2. When faced with changing thermal conditions the roof is allowed to expand and contract in a sliding movement over the clips which helps to prevent tearing around the fastener points.
The only solution for large-span metal roofs
In large-span metal roofing applications, concealed fix systems are the only choice. Considering the size of investment concerned in these applications, the engineering performance of the entire roofing and cladding “system” is critical.
Concealed fix systems enable professional teams to reliably serve the long-term interests of their clients and reduce liability for all concerned. Modern, large span projects dictate the innovative use of concealed fix systems. Designs are increasingly becoming more bold, daring even, and a feverish pursuit of sustainability seems to dominate the realm of architectural design. It is in exactly this nuanced space, that concealed fix systems can contribute massively towards sustainability and a solid return on the client’s investment.
Steel used is 100% recyclable
The steel used in concealed fix profiles is 100% recyclable, and modern coating technologies render the roof much cooler than what was conventionally achievable.
The latest polyester paints display unsurpassed colour stability with cutting-edge technologies being applied to ensure maximum effectiveness and reflectivity under harsh UV elements. These modern adaptations of traditional technology take a massive leap towards sustainability – without compromising economical prudence.
The secret to robust concealed fix solutions is in the clip
When it comes to concealed fix roofing, the design of the clips is of paramount importance. The clip serves as the “anchor” which secures the sheet to the sub-structure and holds it down in all weather conditions.
The material and thickness of the clip helps to determine its inherent strength, which in turn determines the minimum wind-uplift resistance requirements for a particular roof.
The overall “system” design defines the manner in which the clip locks into the sheet profile. The clip should engage every rib of the profile to prevent wind cushioning under the unsecured rib, and distorting the sheet off the clip.
As a general rule, the more ribs that are secured with a positive clasp holding it to the purlin, the stronger the wind-uplift resistance. If not positively secured, the ribs should be shaped to provide a strong and stable interlock with the clip at every point. A complete system will also offer a high wind load detailing for particular terrain categories or design parameters such as wide overhangs.
Additional benefits of concealed fix roofing systems
– Aesthetically pleasing with no visible fasteners on the roof
– Versatile application on both high pitched roof slopes and almost flat roofs
– Watertight roofs with no exposed fixings and therefore less prone to leakage
– No limit to the length of the roof sheet as roof sheets that exceed transportable lengths can be rolled on site to provide a fit for purpose solution
– No end laps eliminate potential for ingress at laps along with accelerated corrosion
– Outstanding thermal and acoustic performance
– Can be used in conjunction with Green Roof systems
– Increasingly secure with non-visible fixtures preventing easy removal to gain access to a building
– Roof sheets can be disassembled and recovered for later use
– Ideal for rainwater harvesting
Safintra’s concealed fix roofing profiles
Safintra offers three concealed fix roofing profiles, namely Saflok 700, Saflok 410, and Newlok, a standing seam profile. Saflok and Newlok are both concealed fix or secret fix profiles as the anchoring system is not visible. This allows unrestrained thermal expansion and contraction. The difference between concealed fix (Saflok) and standing seam (Newlok) is that the Newlok profile can be seamed either mechanically or by hand, giving it additional wind hold-down capability.
Saflok concealed fix roofing is the most widely specified system available. The precisely engineered clip and the dimensional consistency of the Saflok profiled sheet provide a robust and reliable roof system. Over 10-million square metres of this sheeting have been installed over the past three decades in South Africa alone – underlining Saflok’s proven track record and best-in-class credentials.
Saflok 700 is the most advanced wide-coverage concealed fix system on the market with a cover width of 700mm per sheet for fast, cost-effective installation. The profile’s re-engineered clips ensure superb sheet engagement at every rib, and total stability at the male-female lap while its deep pans allow for excellent water run-off, even at a 2 degree pitch.
The profile has achieved significant market share over the past 30 years and has a proven track record. Saflok 700 has an unapologetically rugged yet aesthetically pleasing design, and its components include detailing for both high wind loads and structurally challenging installations.
Saflok 410 is Safintra’s flagship product within the concealed fix market. It has an effective cover width of 410mm and is an angular interlocking trapezoidal rib profile which can be roll-formed on site.
The key to Saflok 410’s unmatched performance is the interaction between the profile’s innovative geometric design and the performance of its second-generation clip. This winning formula has proven itself in the testing grounds of the Western Cape and Eastern Cape where typically high wind loads have allowed Safintra to build up a track record for the Saflok 410 profile as truly the best in its class.
The Saflok 410 roofing system has been independently tested at the Council for Scientific and Industrial Research (CSIR) by Dr Adam Goliger, widely regarded as the leading engineer in the field of wind upliftment and as one of the pioneers of topographical wind environmental studies. During the tests, the profile excelled in the following:
• Exceptional uplift performance and serviceability (ideally suited to push the boundaries of modern design criteria)
• Exceptional point load carrying ability (reduced damage due to foot traffic and the subsequent installation of rooftop items such as HVAC or solar panels which impose point loads)
Newlok is a concealed fix, standing seam profile with an effective cover width of 445mm and a rib height of 50.8mm.
It is designed for use on low pitched roofs and can withstand high wind conditions in industrial, commercial and residential applications. Newlok’s unique interlocking clipping system incorporates a concealed cleat to positively hold down the male-female joint at every rib.
The two-part cleat allows for natural thermal expansion and contraction of the sheet, while the rib height delivers optimal water shedding capabilities at slopes as low as 1.5°. The profile can be roll-formed by a mobile mill on the building site, in continuous lengths.
Safintra now has mobile mills across the country
Safintra’s award-winning concealed fix profiles are the preferred choice among professionals in the South African construction industry. These profiles have proven their worth over the past decades in high wind environments, giving owners complete peace of mind that their roofing system will remain structurally sound for far longer than its competitors.
Safintra now has mobile mills across the country and roofing sheets can be ordered in any length required although on-site rolling is recommended for lengths in excess of 13.2 metres due to practical transportation requirements. Safintra’s best-in-class concealed fix profiles are backed by a full Safintra warranty and are available countrywide.
As a professional, you should demand full technical details of the system you intend to specify and request technical support throughout the installation itself. Safintra is proud to offer this service free of charge to all its customers from seven branches countrywide.
South African operations are in Johannesburg, Durban, Cape Town, Polokwane, Nelspruit, Gqeberha, Bloemfontein while further operations are in Namibia, Mozambique, Zambia, Malawi, Tanzania, Kenya, Angola, Uganda and others.