SAFLOK 410: CONCEALED FIX ROOFING
Saflok 410® is a concealed fix profile with an effective cover width of 410mm. It is an angular interlocking trapezoidal rib profile, and can be roll-formed on site.
Safintra 0.50mm thick Saflok 410® Colorplus® AZ 150 interlocking roof sheeting fixed to steel internal purlins at 1700mm centres, and ridge/eaves purlins at 1500mm centres using Saflok 410® clips that must be fastened to steel purlins with Fixtite™ or Safintra approved wafer head self-tapping screws, all in accordance with manufacturer’s recommendations. The sheeting will be a double interlocking concealed fix Saflok 410® as manufactured by Safintra, roll-formed in continuous lengths from Aluminium or Aluminium-Zinc coated steel.
The profile shall be roll-formed with 3 ribs at centres not exceeding 205mm and a cover width of 410mm. The male rib is to include spurs to ensure a double interlocking action with adjacent sheets. The minimum rib height shall be 41mm. Two stiffening ribs are incorporated in each pan.
Saflok 410® can be curved or bullnosed to a minimum internal radius of 450mm. Reverse cranking is not possible.
Note that when using Aluminium material on galvanized steel purlins, the use of an isolation tape or similar to prevent the bridging of the two dissimilar materials is recommended. Should the two metals have direct contact it will ultimately result in the manifestation of galvanic corrosion, and the service life of the Aluminium will be compromised.
Material and coating thickness can vary regionally. Consult your local Safintra branch for availability.
PURLIN SPACING & DRAINAGE
Span tables are for Saflok 410® with light foot traffic only. It is based on 1.5kN downward load and 2kPa negative wind loading. The span table below refers to the maximum recommended spans. For further information, consult Safintra’s Technical Department.
Saflok 410® clips are calculated at 145g per clip – You will require approximately 3 clips per m².
The anchor mechanism of the Saflok 410® clip is design registered with South African Design Application No. F2017/00456*.
Concealed fix side cladding must be pierce fixed for prevention of sheet movement due to gravity. Pierce fix the top of the sheets. Internal pierce fixing may be necessary on longer sheets (in consultation with the Structural Engineer). Cladding is to be fixed in the pan of the sheet with #12x25mm Fixtite™ fasteners – Class 4 only.
*Refer to the Safintra Technical Department for more information or raise any enquiries in writing to email@example.com
LENGTH AND ROOF PITCH
Saflok 410® can be ordered in any practical length as per customer requirements. On-site rolling is recommended for lengths in excess of 13.2 metres, limited by space constraints and building design. The minimum roof pitch when using Saflok 410® is 2°.
Clip-in marks and/or faint repetitive waviness, commonly referred to as oil canning, may be witnessed occasionally. This does not indicate any mechanical defect in the sheet.
Where insulation is to be installed, you may need to increase the length of the fasteners given below, depending on the density and thickness of the insulation or packer.
When the fastener is properly tightened:
• Into metal: There should be at least three threads protruding past the purlin you are fixing to.
• Into timber: The fastener must penetrate the timber by at least 30mm.
SAFLOK 410® CLIP
The fully interlocking Saflok 410® clip incorporates one anchor to clasp the middle rib and a dual-action gooseneck to positively hold down the male-female joint.
- Provides full-width engagement on the gooseneck male rib joint.
- The Saflok 410® clip demonstrates an excellent hold down capability in negative wind uplift load tests.
- Engineer-designed geometry of the anchor unit for optimal performance under high wind loads and foot traffic.
- Entire clip is manufactured from 0.8mm Aluminium-Zinc coated steel for compatibility with sheeting.
Please note that clips can be manufactured in alternative metals to ensure metal compatibility.
SAFLOK 410® INSTALLATION
- Starting with the female rib first, align the first row of clips and fasten on all three fastening positions.
- Lay the first sheet down over the clips. Starting at the eave side, clip the sheet onto the clips by first engaging the anchors and then engaging the female rib over the gooseneck and male rib.
- Engage the gooseneck of the next row of clips over the male rib and fasten on all three fasteners. Ensure the male leading edge has adequate support (might require slight lifting of the male rib or rotation of the clip). Repeat from step 2.
During installation, clean the roof daily by removing all swarf, pop rivets and unused fasteners or any other debris.
A system performance warranty will be applicable provided that the installation has been performed by a Safintra Approved Roofing Contractor and the project has been inspected by Safintra.
SPECIALISED FIXING ACCESSORIES
Polysliders are specifically designed for polycarbonate or fibreglass sheeting and allow for a large amount of thermal expansion. This clip works in conjunction with the saddle washers which are positively fixed to the sliding bracket. This clip is also used for Saflok 410® sheeting around the perimeters and exposed areas where high wind load conditions prevail.
Overhangs are prone to a build up of wind pressure and are considered to be the weak point of any roof. All overhangs larger than 600mm need to be positively fixed with a high wind load clip or saddle washer (always allowing for thermal cycling). These include canopies, walkways, lean-to roofs, loading bays and decorative roofs.
- Align the first row of the polyslider baseplates and fasten through the pre-drilled holes in the two positions where the slider brackets attach.
- Connect the slider brackets to the baseplate and lay the first sheet over the slider brackets.
- Place saddle washers over the first two ribs above the purlin, and fasten the saddle washers through the ribs into the slider brackets.
- Place the next row of baseplates and fasten. Overlap the end fastening positions to self-align the row of baseplates. Repeat from step 2.
All Polycarbonate sheet installations (including, but not limited to in-plane installations) with Safintra roofing/cladding profiles should be done in accordance to SANS 10237:2017 (Annexure E Rooflights).
NOTE 7 In a springing or draping application, consideration should be given for the inclusion of high wind load brackets at the eaves.
The bonded saddle washer can only be fixed from the top.
SPECIALISED FLASHING INSTALLATION
When installing bull-nosed sheeting or Aluminium sheeting, the use of flashing slider brackets is recommended for sheets with lengths in excess of 15 metres. Please consult Safintra’s Technical Department for assistance.
The clip-on slider clips onto the rib of the Saflok® profile to fix longitudinal flashing (barge, sidewall) to the sheeting without the need for fasteners piercing the sheet. The clip will allow for more thermal expansion than the F10 bracket. Therefore recommended for lengths exceeding 30 metres. The clips are available in Aluminium-Zinc coated steel or Stainless Steel Grade 304.
F10 BRACKET FOR FLASHINGS
F10 brackets are used to fix flashing onto Saflok® profiles without drilling directly into the sheet. The bracket allows for minimal expansion. Brackets are available in Aluminium-Zinc coated steel, Stainless Steel Grade 304 or Aluminium.
This clip is positively fixed. Care should be taken when detailing industrial length sheeting and flashings due to thermal expansion.
2-PIECE SLIDER FOR FLASHINGS
The 2-piece sliders are used to fix transverse flashings (apex, ridge, headwall) to the sheeting without drilling directly into the sheet. This bracket will allow for up to 50mm of thermal expansion. Due to the effects of thermal expansion and contraction, “first sheet” installation should never be attempted by positively fixing the sheet to the structure. Sliders are available in Aluminium-Zinc coated steel, Stainless Steel Grade 304 or Aluminium.
The Saflok starter bracket is used to secure the first and/or last rib of the edge sheet without restricting thermal expansion. Sliders are available in Aluminium-Zinc coated steel, Stainless Steel Grade 304 or Aluminium.
The bending tool is used to bend the pan up on the ridge side of the sheet to create a water barrier (also known as the tanking or turning up of the sheet). The lipping tool is used on the eave side of the sheet to create a turned down lip (also known as the lipping or turning down of the sheet).
Saflok 410® bending tool application
Saflok 410® lipping tool application
Saflok 410® sheets may be cranked and bullnosed but not reverse cranked. The minimum radius is 450mm. On-site cranking is available on request.
Natural springing occurs at a 36m radius in the convex and at a 60m radius in the concave. It is important to reduce purlin spacings by 20% when spring curving a roof. Oil canning may be expected.
ROLLING STRAIGHT ONTO A ROOF
It is possible to roll-form straight onto a roof using a scaffold ramp. The limitations are the building height and space needed to roll. A departure angle of 10° is the maximum allowed at any time. A greater angle would damage the sheet when leaving the mill and again when bending to settle onto the roof.
A length variation range of +10mm and -0mm, and a width tolerance of ±3mm is permissible.