How to Design, Plan, Order and Build a beautiful Merbau Timber Deck

1. Measure and Design it
2. Plan and Measure Up
3. Read Construction Guidelines Below
4. Calculate and Order Products needed
5. Call DIRECTLINE Timbers helpful staff anytime
6. Send us photos of your magnificent work for our Facebook page

Buy everything you need to build this Merbau Deck from the Sunshine Coast’s Premier Independent Timber Specialists – and get the best price and best service!


Call us now for expert advice on you next project
Tel: 07 54792344

Design Considerations for your Merbau Deck

How to build a Merbau Deck:

Once you have planned the location and size of your deck there are six steps in building it:

  • Step 1 Timber Selection

    Calculate your total length of decking boards and call DIRECTLINE to order

  • Step 2. Foundations

    Calculate the number of stirrups and quantity of pre-mix you need and call DIRECTLINE to order

  • Step 3 Installing Posts & Bearers

    Calculate the number of posts and bearers, galvanised bolts and hanger you need and call DIRECTLINE to order

  • Step 4 Installing Joists

    Calculate the number of Joists you need and call DIRECTLINE to order

  • Step 5 Laying Decking

    Calculate the number of galvanised fixing nails  you need and call DIRECTLINE to order

  • Step 5 Coatings & Finishing Touches

    Decide on the colour of finish (see our showroom for examples) you need and call DIRECTLINE to order

Components of a typical deck:


Timber Sizes

Typical sizes – however there are certainly other sizes available.
Most Merbau timber decking is sold in random lengths – set lengths subject to availability.

Ordering Materials for your Merbau Deck

  • Step 1 Merbou Decking Timber

    Select timber size dependant look required.

  • Step 2. Foundations

    Hot dipped galvanised steel stirrups
    hot dipped galvanised steel stirrups

    Select stirrup size to match posts.

    Pre-Mix Concrete:


  • Step 3 Posts & Bearers


    treated pine posts


    Select timber size dependant on span – see Residential Timber Decks PDF download.

    treated pine bearers

    Hot dipped galvanised Bolts


    Joist hangers


  • Step 4 Treated Pine Joists

    Select timber size dependant on span – see Residential Timber Decks PDF download.


  • Step 5 Laying Decking

    Hot dipped galvanised Decking Nails


  • Step 6 Coatings & Finishing Touches


Final Step:

Calculating the price of materials for your Merbau Deck

Calculate the quantities needed then call DIRECTLINE Timbers for free engineering and design advice. Call the helpful and experienced staff or drop in and say hello

Phone(07) 5479 2344
6-8 Kayleigh Dr
Maroochydore QLD 4558

Opening Hours: Weekdays: 6:30 – 4:30 Saturday 8:00 – 12:00

Construction Considerations for your Merbau Deck

Step 1 Timber Selection


  • Posts – preservative treated pine or treated hardwood

  • Bearers & Joists – preservative treated pine or hardwood.

  • Hardwood decking boards  – Merbau dressed all round.

Step 2 Foundations

Deck_project_foundations_diag1 copy

  • Timber posts should  be fixed to hot dipped galvanised steel stirrups set in concrete

  • A minimum clearance of 75 mm shall be provided between the top of the concrete footing and the bottom of the post as a termite inspection zone.

  • Posts embedded in the ground shall be a durable species

Step 3 Installing Bearers

Deck_project_brackets copy

  • Install Posts
  • Install Bearers
  • Using the correct fixings
  • Setting up the correct bracing
  • Bearers shall be adequately fixed to posts.  Where bearers sit on top of posts, fixed with proprietary post caps or brackets in accordance with manufacturer’s instructions.

Step 4 Installing Joists


  • Joists should be fixed on top of bearers or ledgers at 450 mm maximum spacing with either two 75 mm x 3.15 mm skew nails or proprietary framing anchors or brackets.
  • Nails for proprietory connectors to be hot dipped Galvanished Sizes shown in Table 4 in download PDF list.
  • Joists 50 mm wide are recommended because they are less prone to splitting and provide better bearing and fixing for decking boards at joins and ends.
  • For joists spans over 3 m, additional herringbone strutting or solid blocking should be provided in evenly spaced rows as follows.
  • Handrails and Balustrades Decks more than one metre above ground require a handrail or balustrade. Refer to TDS 23 for Timber Handrails and Balustrades.

Step 5 Laying Decking

Deck_project_decking copy

  • Decking boards are available plain (square edged), with pencil round or arrised edges, or with one reeded or ribbed surface – although reeded have a lower life span.
  • Narrow boards are recommended as they shed water more readily and are therefore less prone to cupping and twisting.
  • Butt joints shall be staggered (i.e. not on adjoining boards). A slight back-cut will assist in obtaining a tight fit at butt ends.
  • Each board shall be fixed at every joist crossing with two nails.
  • Nail holes at butt joints shall be predrilled (80% nail diameter) to avoid splitting.
  • Nails shall be driven flush with surface (not punched).

Step 6 Coatings & Finishing Touches


  • All decks should have a finish applied as protection against the weathering effects of sun and rain.
  • Unprotected timber exposed to the weather will fade to a silver-grey colour and could distort and develop splitting and surface checking.
  • One coat of a water repellent preservative or an oil based primer plus one coat of the selected finish shall be applied to the top surface of joists and to all surfaces of decking (including cut ends) prior to fixing.
  • Additional coats shall be applied (to manufacturer’s instructions) to the top surface of decking after fixing.