Stramit FarLap® Roof Lap Joint System for Stramit Speed Deck Ultra®



Increased safety
– smaller roofing crews
– lighter, shorter sheets to carry
– smaller pack mass
– roof sheets easier to lay and handle.
• Low profile seal – enhanced visual roof continuity.
• Economical – low cost solution for long roofs.
• Suits Stramit Speed Deck Ultra® decking profile – for roof slopes as low as 1 degree.
• Sealed – for enhanced energy efficiency.
• Independently weather tested
– peace of mind
– confidence in system.
• Easy to use
– snap-in-place for fast and reliable installation
– can be installed at any support member along the roof run.
• Advantage at restricted access sites
– shorter product lengths
– shorter trucks
– easier access
– less storage space.
• Uniform purlin height – no step in supporting structure, no need for structural modification, and no additional purlin.
• High technology materials for structural connections and weather performance.
• Proven materials
– provide a durable solution
– preserve normal roof waranty.
• Shorter length sheets
– lower transport and handling costs
– smaller site crane required
– less thermal expansion and contraction.
• Usable in multiple rows – allows long monoslope roofs.



Spans / Pressures

 When used with the Stramit FarLap® roof lap joint system, the non-cyclonic spans and pressures provided in the Stramit Speed Deck Ultra® decking product technical manual and relevant Stramit Design Guides remain unchanged with the following conditions:

• the lapping spans at each joint shall be regarded as end spans for the purpose of determining wind and foot traffic capacity.

• to ensure drainage, the overlapping span should be no less than:
      – 1700mm for a 1 degree slope
      – 1200mm for a 1.5 degree slope
      – 850mm for slopes of 2 degrees or greater alternatively, shorter spans can be used if a 10mm durable packer is placed beneath the Stramit Speed Deck Ultra® clip at the support above
         the joint.


Contact your local Stramit office for details. If a spacer is used, the screw length needs to be commensurately longer.

Cyclonic Areas

The Stramit FarLap® roof lap joint system for Stramit Speed Deck Ultra® can be used in cyclonic areas.  Please refer to the Stramit Cyclonic® Areas Roof and Wall Cladding brochure on the Stramit website


Support Structure

Lap joints using the Stramit FarLap® roof lap joint system do not require purlin step joints. The supporting structural steel can be designed and detailed so that all the roof purlins are in the same plane. Cleats must be arranged to suit purlin spacings consistent with any required change in sheet spacing arising from the Spans/Pressures clause above.


Penetrations and Obstructions

No obstruction to the water flow should be placed across the  Stramit FarLap®  joint, nor should the joint be crushed by any load.  All roof penetrations should be at least 1500 mm away from the  Stramit FarLap®  joint.


Translucent Sheeting

Where required, translucent sheeting must be specified to be lapped at the Stramit FarLap® joint. Translucent sheeting for the lower run should be fixed before laying decking on an upper run.

Contact Ampelite Australia or other suitable manufacturer for details of the joint and fastening.




Installation Procedure

Stramit FarLap® roof lap joint units are readily installed.  No additional fastenings are required. It is however important that the roofing sheets at each overlapping joint be carefully aligned. The summarised procedure is:
1 Alignment for the first row of clips for both the lower and all upper runs should be determined before commencing laying the deck on the lower run. This ensures the lower and upper runs are accurately aligned.
2 Install the lower deck sheet/s then turn-up the high end in every pan using the Stramit FarLap® turn-up/down tool.
3 Position the Stramit FarLap® roof lap joint units by simply snapping in to place 200mm from the sheet end on each rib, within 50mm of the Stramit Speed Deck Ultra® fixing clips on the purlin.

Join subsequent units using the nylon link pins that push into mating holes as shown in the three steps A to C below. This can be done one at a time just before installing on the sheets, or in a long chain of Stramit FarLap® units connected together prior to installation on multiple sheets at the same time.
4 Commence the higher sheet run by carefully aligning edges with the first lower sheet and positioning with an overhang of 150mm.
5 Turn down the upper sheet end using the Stramit FarLap® turn-up/down tool.
6 Complete the upper sheet run.
7 Barge capping needs to accommodate the slight rise in the joint area.
An illustrated leaflet is provided with each order containing fixing instructions.


We recommend caution be taken when walking on any roof. When walking on Stramit® decking always wear flat rubber soled shoes and place feet only in the pans except at supports, taking care to avoid the last pan or two near edges of the metal roof area. 

Walk only in pans, or on ribs at purlin supports.

Good Practice

Stramit recommends that good trade practice be followed when using this product, such as that found in Australian Standards Handbook HB39.


Stramit FarLap® roof lap joint units can be easily cut across the foam section using a retractable box cutter or suitable sharp cutting implement. Do not cut the nylon connectors. Please dispose of any off-cuts considerately.



Important: Please note, when ordering Stramit Speed Deck Ultra® decking for use with Stramit FarLap® joint, allowance must be made for an additional overlap of 350mm at each lap joint along the roof run length:
      – Bottom sheet + 200mm
      – Intermediate sheet + 350mm
      – Top sheet +150mm
Sheets must be measured to ensure the Stramit FarLap® joint is installed over a supporting purlin. 
Stramit FarLap® roof lap joint units for supply with Stramit Speed Deck Ultra® decking can be ordered from your nearest Stramit location or distributor of Stramit® products.


Delivery can normally be made within 48 hours, subject to the delivery location, quantity and material availability, or can be at a pre-arranged date and time. Please ensure that suitable arrangements have been made for truck unloading, as this is the responsibility of the receiver. Please recover boxes and transfer to a recycling facility. 


 Prices for Stramit FarLap® roof lap joint units (to be supplied with Stramit Speed Deck Ultra® decking) can be obtained from your nearest Stramit location or
distributor of Stramit® products. As Stramit does not provide an installation service, ask your tradesperson for a supply & fix price. Contact your nearest Stramit
location for the names of suitable tradespersons.


Stramit FarLap® roof lap joint units are supplied prepackaged in recyclable cardboard boxes with 20 units (for 14m of roof joint width) and two spare links in each box.

Related Products

 Stramit Speed Deck Ultra® decking -
concealed fix roof sheeting
Stramit FarLap® Turn-Up/Down Tool -
for sheet end preparation at FarLap® joint
Stramit Universal Speed Deck Ultra® Turn-Up/Down Tool -
for sheet end preparation at ridge and eave
Ridge Capping
standard or custom dimensions
a range of custom flashings
Filler Strips
top and bottom; for eaves, ridge and joint sealing
Insulation & Roofing Mesh
a range of mesh, sisalation, plain & foil backed blanket
Translucent Sheeting
glass fibre sheeting in a range of shades and densities
Note that the preferred arrangement for translucent sheeting, when used with the Stramit FarLap® roof lap joint system, requires that the sheet lap is at the same position. Contact your nearest Stramit location for details.


Further Information

As well as our standard range of Technical Manuals, Installation Leaflets, Case Studies and other promotional literature Stramit has a series of Guides to aid design.
These include:
• Roof & Wall Flashing Guide
• Roof Slope Guide
• Foot Traffic Guide
• Concealed Fixed Decking
• Bullnosing, Curving and Crimping
• Acoustic Panels
• Cyclonic Areas
• Spring Curving Guide
Please contact your nearest Stramit location for any of these guides or other literature.

Other Products

Stramit offers a wide range of building products, including:
• Purlins and girts
• Formwork decking
• Roof and wall sheeting
• Lightweight structural sections
• Truss components
• Gutters and downpipes
• Fascias
• Custom flashings
• Insulating products
• Fasteners