Air-dried Canadian western red cedar horizontal weatherboarding
H21 – Timber Weatherboarding
General
- Air-dried Canadian western red cedar boards fixed horizontally to softwood battens over a breather membrane. Intended for use as external wall cladding in above-ground applications (Use Class 3).
Products
Timber Weatherboarding
- Species: Canadian western red cedar (Thuja plicata)
- Supplied by: Vastern Timber. sales@vastern.co.uk . 01793853281
- Origin: PEFC certified forests in Canada
- Quality: BS1186-3 Class 1 / BS EN942:2007 J20
- Preservative impregnation: None
- Fire retardant impregnation: None
- Orientation: Horizontal
- Moisture content at time of fixing: Air dried (16–19%)
- Profile: VHL5C, VHL6C, VHL7C, VHL8C, VSP1C, VSL1C, VSL3C, VTG1C, VTG2C, VTG3C, VTG4AC, VTG5AC
(Delete as appropriate) - Overall face width: 65mm, 90mm, 140mm
(Delete as appropriate) - Thickness: 18mm
- Length: Random 1.8 – 3.7m+, small % down to 1.5m
- Durability: Class 2 (BS EN 350-2)
- Service life: 60 years
- Reaction to fire: Euroclass F (untested) / D-s2, d0 (with treatment)
- UKCA Compliant. Conforms to BS EN 14915_2013 + A2:2020
Battens and counter battens
- Regularized preservative treated softwood or Thermowood battens, free from decay, excessive insect attack and with no knots wider than half the section width.
- Maximum moisture content at time of fixing: 20%
- Minimum 38mm thick and 45mm wide
Screws or nails
- Weatherboarding: 50mm Stainless steel ring shank nails or hardened stainless steel trim head screws.
Execution
General
- Installation standard: In accordance with BS 8605-1:2014 and TRADA External Timber Cladding 2nd Edition.
- Handling: Avoid damage during handling. Store under cover with ventilation.
- Waste and offcuts: Recycle, burn, or compost. Supplied untreated and uncoated for easy end-of-life recovery.
Battens and counter battens
Setting out:
- Single vertical batten over breather membrane on exterior wall
- Install in straight vertical lines at 400–500mm centres, fixed directly through the breather membrane into substrate
- Fastener heads to finish flush with or slightly below batten face
- Install insect mesh at top, bottom to seal off cavity behind cladding
- Insert detail for Cavity Barrier
- Leave a minimum of 10mm drainage gap at base of cladding
- Maintain cavity behind cladding in all places.
- Treated timber: Treat surfaces exposed by cutting or drilling with two coats of a preservative solution recommended by supplier
Weatherboarding
- Install boards securely and neatly to avoid bowing, splitting, indentations or other unsightly characteristics
- Install with an expansion gap of at least 2mm to allow for movement
- Position board ends over battens
- Fixing method: Pilot drill and fix through face or tongue of board
(Delete as appropriate) - Ensure all fixings are installed in a consistent and straight line, both vertically and horizontally to maintain a uniform appearance
- Screw or nail heads to finish flush with or slightly below surface of wood. Avoid protruding or deeply recessed fastener heads
Disclaimer
While the utmost care has been taken to provide accurate and relevant information, Vastern Timber shall not be held responsible for any consequences arising from errors or omissions within this information, nor for any damages resulting from the use of this information.
