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Yellow Balau (Bangkirai) Decking Smooth 21 x 145mm

Availability: In stock

Price From: £12.76 (Exc vat:) £15.31 (Inc vat:)
(ex vat) (inc vat)
Price per linear metre £5.24 £6.29
Price per square metre £34.95 £41.94

Quick Overview

  • Interlocking grain and fine even texture
  • Hard, heavy and strong suited for deck construction
  • Smooth face with beveled edges
  • Colours vary from yellow-brown to pale red-brown

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Price From: £12.76 (Exc vat:) £15.31 (Inc vat:)

Yellow Balau Decking

Yellow Balau decking boards are supplied with a smooth face and beveled edges.

Yellow Balau (pronounced Bal-Ow) - Bangkirai - is a very durable Malaysian hardwood. It is a hard, heavy and strong timber that is well suited to deck construction.

Yellow Balau decking has an interlocking grain and a fine and even texture. Its colour varies between yellowish-brown, brown and pale reddish-brown. Occasional pinhole and hit and miss is acceptable within the grading rules of Yellow Balau decking.

Storage and Handling 

For best results store your Yellow Balau decking out of direct sunlight and do not expose it to weather before installation.  Keep the boards off the ground by stacking them flat on timbers placed on the ground; this allows air to circulate around the stack.  Cover your deck boards with a waterproof breathable sheet to protect them from sun and rain until you are ready to install them.



Deck Board Spans

21 x 145mm Yellow Balau decking should be installed with joists spaced at 400mm centres.  When installing the boards diagonally the joists should be spaced at 300mm centres.


Deck Board Spacing

21 x 145mm Yellow Balau decking should be installed with a 5mm gap between the boards.  The space between the boards allows for air circulation and slight expansion with changes to the humidity level.



It is important to allow adequate air circulation underneath the deck to prevent cupping and warping of the boards.  It is recommended that a vapour barrier is used on the ground to prevent moisture from absorbing into the underside of the deck boards.



There are a number of different options available for fastening deck boards to the joists.  We recommend screwing through the face of every board using 4.5 x 60mm Fin/Trim™ Stainless Steel screws by GRK Fasteners™.  Fix two screws into every joist at quarter points on the deck board (36mm from each edge).  We recommend that pilot holes are drilled prior to inserting the screws.  This is particularly important at the ends of the boards to prevent splitting.  GRK’s specially formulated Pheinox stainless steel screws will flex slightly as the wood expands and contracts as the level of humidity changes with the changing of the seasons.

For a cleaner finish we suggest recessing the screws and using Yellow Balau plugs to hide the screw heads.  Plugs can be cut from off-cuts of decking using a relatively inexpensive drill attachment called a plug cutter. 


Hardwood wrench

The longer the deck board the greater the tendency for it to be slightly bowed. To overcome this, most professional deck installers will carry a tool called a Hardwood Wrench, or Bow wrench, which enables the user to easily straighten a bowed board single handed as it is installed.  The Bow wrench is relatively inexpensive and can save a lot of time, so it’s worth buying even if you only use it for one project.  It can also he hired from some tool hire stores.

End Sealer

Yellow Balau decking from Silva Timber is end-sealed during the manufacturing process to help prevent splitting and checking on the ends of boards.  We recommend that if the boards are cut during installation then the exposed end grain should be sealed as soon as possible.   A clear, water-resistant wax such as Osmo Wax End Sealer should be used.



Even though Yellow Balau is highly durable in its natural state we recommend that Yellow Balau decking be finished on all four sides prior to installation to help prevent surface checking, discolouration and cupping.  In dry sunny conditions, it is especially important to finish the deck boards prior to exposure to the weather.  Finishing the underside of your decking will inhibit moisture from absorbing into the wood and thus reduce the potential for cupping.

Because Yellow Balau is an incredibly dense species it is essential to sand the deck boards prior to applying the finish.  The sanding process opens up the cells on the surface to allow the stain to properly penetrate.  This is a very important stage of the finishing process as it facilitates deeper penetration of the stain and therefore better protection and longer service life of the stain.  In addition you will achieve a far more consistent appearance making the end result more aesthetically pleasing. 

Aside from preparing the board to accept the finish sanding will also remove any markings that were originally present on the surface of the boards. 

To maintain the natural look of the wood we recommend using a high quality penetrating oil with a UV inhibitor such as Dec by Sansin

If a natural weathered appearance is preferred we recommend applying Sioo by which protects the wood whilst allowing it to gradually season and weather over time.

Apply the finish according to the manufacturer’s instructions.


Cleaning and Maintenance 

Your Yellow Balau deck will benefit from regular cleaning.  Brush the deck with a stiff broom to remove dirt and dead leaves, and ensure that the gaps between the boards are clear of organic debris.  Clean the deck periodically with Multi Wash by Sansin® to remove grime and mildew.  Yellow Balau decking can be pressure washed, but it is important to select a low setting to prevent the wood fibres on the surface from being damaged.

If your Yellow Balau deck is weathered it is possible to restore the natural colour with Wood Cleaner by Sansin®.  This product will remove weathering, mould, algae, mildew and iron stains and prepares the surface for recoating. 

If an existing finish or stain has broken down it can be removed using Paint and Stain Remover by Sansin®.  This product will remove most failed oil-based or latex finishes, extreme weathering, water stains, mould and mildew and restore wood to its natural colour.



Yellow Balau decking can be crosscut with good quality chop saw using a tungsten carbide tipped blade.  Ripping can be done on a standard table saw, using a good quality, well-aligned fence and a tungsten carbide tipped blade.  When drilling, always use the highest quality drill bits available. If screwing through the face, use a countersink bit with a positive stop to ensure that all the screw heads end up at a consistent depth.  Screws can be lubricated to make installation easier.

Routing or planing can be done with either high speed tungsten carbide cutters. The feed speed should be fairly slow. 



A dust mask and eye protection should always be worn when working with any wood.  Avoid the inhalation of wood dust.  We recommend a dust mask with an activated carbon filter. Some people may have an allergic reaction to hardwood dust.  Remove wood splinters immediately to prevent infection.



To ensure its quality, Yellow Balau decking from Silva is carefully manufactured, graded and inspected at source.  It is inspected again during the order picking process prior to despatch.  However, Yellow Balau decking is a natural wood product and is subject to variations in weight, density, colour, grain and performance. Yellow Balau decking is subject to dimensional changes as the moisture content in the wood fluctuates with humidity in the air. Swelling, shrinkage, checking, and other movement of individual pieces are normal occurrences in wood decking.


1m2 = 6.90 metres of board


Standard & Better

Silva Timber Associates