Fresh-sawn larch feather-edge weatherboarding
H21 – Timber Weatherboarding
General
- Fresh sawn British larch feather-edge 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: British larch (Larix decidua)
- Supplied by: Vastern Timber. sales@vastern.co.uk . 01793853281
- Origin: Legal and well-managed forests in England & Wales
- Quality: BS1186-3 Class 3 / BS EN942:2007 J50
- Preservative impregnation: None
- Fire retardant impregnation: None
- Orientation: Horizontal
- Moisture content at time of fixing: Supplied wet (fresh sawn)
- Profile: VFE1, VFE2
(Delete as appropriate) - Overall face width: 150mm, 175mm, 200mm
(Delete as appropriate) - Thickness: 4–18mm, 6–23mm
(Delete as appropriate) - Length: Random 1.8 – 3.7m+
- Durability: Class 3–4 (BS EN 350-2)
- Service life: 30 years
- Reaction to fire: Euroclass F (untested) / D-s2, d0
- 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
- Minimum 45mm thick and 45mm wide
- Maximum moisture content at time of fixing: 20%
Screws or Nails
- Weatherboarding: 65–75mm stainless steel ring shank nails
Execution
General
- Installation standard: In accordance with BS 8605-1:2014 and TRADA External Timber Cladding 2nd Edition
- Avoid installing during warm summer months
- 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
- 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 and 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 overlap equivalent to 25% of board width
- Position board ends over battens
- Fixing method: Hand nail or first fix nail gun. Locate nail just above the upper edge of previous board
- 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.
