What Size Decking Boards Are Most Popular?
While traditional Australian homes often feature narrow 70mm decking on front verandahs, modern trends have shifted toward wider boards, making 140x19mm decking the current best-selling profile.
Wider boards can be slightly more expensive per square metre, but need fewer screws across the full deck than narrower boards. Once you factor in the cost of screws, the price difference is usually marginal.
140mm Merbau decking boards create a sleek, seam-free look on a large deck
How Does Board Width Affect the Look of My Deck?
Wide boards create a sleek, resort-style look with fewer seam lines, making large decks feel open and contemporary. On smaller decks, however, fewer wide boards can feel out of proportion. If you're working with a compact space, no matter which size you choose, focus on running your boards parallel to the longest view line to maximise perceived space.
Check out our Merbau Decking Range to find both narrow and wide profile options.
What Size Decking Boards Should I Use for a Low-Level Deck?
Merbau is the most stable decking timber available on the market and will give a favourable performance in comparison with other decking species under most scenarios.
Choose 90mm boards for low-level decks. These offer a more stable solution, with more frequent gapping allowing for improved ventilation.
90mm Merbau decking boards installed on a low-level deck, with more frequent gapping for improved ventilation
If you decide to use a wider board, increasing your gapping and installing a form of ventilation and drainage system underneath your deck is critical. Download our Merbau Decking Ventilation and Drainage Guide for more detailed information.
I Have a Traditional Victorian Weatherboard Cottage. Can I still get 70mm Decking to Replace My Old Deck?
Yes, while the 70x19mm profile is no longer sold within the decking range, our 19mm fence pickets and screening are made to the same specifications as our decking, making them a suitable equivalent. SpecRite Merbau 70x19mm Fence Pickets and 70x19mm Screening can be used for homes that feature traditional narrow decking boards on front verandahs.
If you want an even narrower profile, SpecRite Merbau 42x19mm Screening is also a suitable swap.
What Other Options Are There?
An alternative is to mix it up and create a unique space by combining both board widths.
You can simply alternate 90mm and 140mm boards, or consider a repeated pattern.
Option 1: Alternating Pattern
Use a pattern to make your deck more unique, for example, try a repeated pattern of three narrow 90mm boards followed by a single 140mm board:
Alternating decking pattern using three 90mm boards to one 140mm board for a unique Merbau deck design
Designer Tip: if you’re confident with a mitre saw, try mitring the ends of your decking boards, and let the pattern flow down the side of your deck like a waterfall.
Otherwise, a fascia frame also looks great with this pattern style.
Mixed-width Merbau decking pattern finished with a fascia frame for a clean edge
Option 2: Wider Picture Frame Border
For a simple, but classy look, use 140mm decking to frame your 90mm deck, or vice versa.
140mm Merbau decking used as a picture frame border around a 90mm deck
Contrasting board widths for different purposes can make your deck look professionally designed, taking the aesthetic to the next level.
If you’re opting for a combination of widths, be sure to average the required 5% gapping rule across your deck.
For more information about Merbau, see our Complete Guide to Merbau Decking.