Telescopic Sections avoid the need to cut channel sections preceisly to fit.
The upstream telescopic section which is slightly narrower, "telescopes" into the adjacent downstream section.
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Example: 4.52 Metre Section
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1st. Step Cut Telescopic section + ~100mm overlap
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2nd Step. Insert Telescopic section into adjacent downstream section.
The wall of the downstream section is cut to fit in the telescopic section.
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3rd Step. Channel Sections are installed ready for other components to be attached.
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Next: E2 Corners Installation