When laying down the infill, to ensure complete symmetry, calculate the centre line of the deck and have the planks coming off each side......

  This way, any trimming of planks will be uniform on both sides where they meet the margins. Where a plank needs trimming along its length, mark with a pen and then remove any excess with a straight edge and craft knife.

Carefully work around any small deck fittings.  It is quite simple to cut wedges where the in-fill planking meets a margin corner. 

Any small areas remaining can be filled by making even smaller wedges. 

Cut each length roughly to shape leaving a 2mm gap against the margins.  A 5mm channel will be cut later so do not worry if it is not a perfect fit at this stage.

Next, apply the PVC Stelmax adhesive to join the tongue and grooves of adjoining strips and simply slot together to form panels. 

The Stelmax melts the pvc together creating a single sheet. 

Allow the glue to set for one hour.  Any excess glue should be removed from the surface of the material by rubbing with your finger or a rag within 15 – 20 minutes of application. 

When creating panels, you will need to consider how large a panel you can physically handle and bed at a time, the logical sequence of panels and the working time of bedding adhesive for the area you want to lay. 

Once everything is joined, it is advisable to sweep the deck to remove any dust or Teak-it-Easy off-cuts.