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Cladding fitting guide

  • fitting-guide1

Cladding fitting guide

Fitting Cladding

The following is a guide only and all cladding installations should be carried out by an experienced installer using the correct tools and safety equipment to ensure a perfect finish.

The bottom cladding plank is then located firmly in the starter trim and vertical trims, and fixed into place.

  • 1. Fit bottom cladding plank first. Make sure it is fitted horizontally/vertically or at the correct angle.
  • 2. Fix using 30mm cladding nails (see page 35 for full specification of fixings)
  • 3. Fix at centre and work outwards.
  • 4. Allow 5mm expansion gap at each end of plank. (10mm between butting planks).
  • 5. Cut planks to size and shape with a fine pitched saw.
  • 6. Fit subsequent planks into preceding planks.
  • 7. Ensure that the joint is firmly closed and the nail heads concealed.
  • 8. If necessary, cut the top plank to fit the remaining space.
  • 9. Use cladding off cuts placed behind the cut plank at each fixing centre (to act as a spacer).
  • 10. Where sections longer than 5m are to be clad, butt joints of adjacent cladding planks.
  • 11. Cover joint with a centre joint trim (clipped into place).
  • 12. Securely fix ends of butting planks.
  • 13. Position centre joint trims at logical spacings with consideration to aesthetics.
  • 14. Where 2 part trims have been used (internal and external corners) fit the front part of the trim to finish off.
  • 15. Remove protective tape and clean.

Drainage & Ventilation

BS8200:1985 and NHBC Standards Chapter 6.2:1992 - A continuous 10mm ventilation pathway must be maintained behind the cladding with minimum 5000mm2 ventilation slots per metre run at the top and bottom.

Other relevant documentation - Zurich Building Guarantees 1998 (19mm cavity width)

IMPORTANT: Provisions must be made to allow water that has penetrated behind the cladding to drain away. Ventilation is achieved by drilling through the starter trim and top finishing trim - refer to building regs for numbers and sizes.


Maximum windloading based on 600mm batten spacings
- 100mm cladding... 2000Pa
- 150mm cladding... 1350Pa
For increased windloadings reduce batten spacings and fixing centres and check with qualified engineer. As a guide, 400mm batten spacings should be considered for applications over 2 storeys.

Fixing to Non Weatherproof Substrates

- For applications involving non weatherproof substrates (e.g.timber stud wall) a vapour permeable water barrier must be installed behind the battens and cladding.
- When used as a decorative facing on a weather tight masonry wall, a water barrier is not generally necessary. The same applies for fixing distances.


- Cladding should not be taken into account when designing a timber stud to resist racking forces.
- Do not install cladding at ground floor level where severe impacts will occur.

Fitting Trims

Start by fixing battens to the building framework as described on page 35. Battens will also need to be fixed around the periphery of any openings e.g. a window.

Starter Trims

• Before fixing the initial starter trim, make a final inspection of the building substrate and check if any special consideration needs to be taken into account with regards to drainage and ventilation.
• Working from a line level, fix the starter trim to the lower timber batten.
• Use 20mm trim nails.

Vertical Trims

• All vertical trims should then be fixed to perimeter battens.

Cladding Top Finish

• Top trims and trims around windows should also be fixed to perimeter battens.

Internal Corner External Corner

• Fix the back half initially and clip the cover on after cladding has been fitted.