Cost of building a low-level deck?

mathewbenra

Hello,

I live in a very sandy coastal area in victoria. I would like to install a very low (ground level) deck at the rear of my house.

I have been trying to figure out roughly how much it would cost.

The area is roughly 12m wide and 4m deep, I wish to use treated timber throughout the framing, and for the decking itself I would like to use a dark colourd hardwood such as Merbau.

Can someone give a rough idea as to how much this would cost ? Im at a bit of a sticking point and would realy appreciate any help in that matter.

Thankyou

Mathew

MitchellMc

Welcome to the Bunnings Workshop community @mathewbenra. It's sensational to have you join us, and many thanks for your question about costing a deck.

Before you can calculate the cost of the project, you'll need to plan the deck frame. The size and number of joists and the number of posts and footers will significantly impact the cost of your deck. I've compiled a rough guide below of what I believe to be an average construction. Your cost could be more or less, depending on how you choose to build the deck.

If you were to use 90 x 19mm 5.7m SpecRite Merbau Pre-Oiled Decking you would require approximately 98 boards to cover the 12 x 4m deck, that's around $4,200. You'll need around 2550 screws for those boards, or three boxes of these Macsim 10G-10 x 50mm 304 Stainless Steel Torx Decking Screws, at the cost of around $290

Suppose you use 90 x 45mm Outdoor Framing MGP10 H3 Treated Pine 4.2m joists spaced at 450mm centres across the 12000mm span for the joists; you'd require 27 lengths at the cost of $964. Those joists need to be supported every meter or so with something similar to a BuildTuff 300 x 300 x 90mm TuffBlock or post support. You'd need four supports per joist, and you have 27 joists for a total of 108 supports. If you were to use the Tuffblock system, that would be around $1830.

Your approximate total for decking, joists, joist supports and screws would be $7,284.

You should find these guides by @Adam_W useful: How to build a low-level deck, How to build a deck and How to select decking timber.

I also suggest having a look at the Bunnings deck-building guide:

Please let me know if you have any questions.

Mitchell

mathewbenra

Hi Mitchell,

Thank you very much for the helpfull information.

Mathew

MitchellMc

My pleasure @mathewbenra.

Please keep us updated on your project and reach out if you need further assistance.

Mitchell

MikeTNZ

Hi @mathewbenra,

Thanks for asking the question here at Bunnings Workshop.

Further to what @MitchellMc mentioned, I would personally specify stainless steel fixings and fasteners, if you are close to the sea.

Using galvanised or Japanned steel fasteners is false economy when you might have to replace them 2 or so years after the deck is completed,

because they may have rusted out due to salty air from the sea.

You need at least 316 or 360 grade fasteners around salty environments, 316 is the minimum, try and get something of a higher number than that, yes they are more expensive, but do something once and do it correctly.

I'm looking forward to seeing the pictures from this install.

And, of course, if you need further help, by all means, type away with a new post.

Cheers,

Mike T.

mathewbenra

Thanks mike, that makes perfect sense.
Mathew