Adjustable steel posts for elevated deck?

[hazzabatt]

I wish to build a deck about 3m x 3 m or so. The deck will be about 600 mm above ground level.  I intend to use timber boards supported by 100mm joists with 200 mm beams underneath.

For the decking I might also use the Merbau panels approximately 1100 mm x 550 mm sold by Bunnings

So the subframe will be around 300 mm deep.

I will put brick or concrete pads underneath for supporting piers. That means my so-called piers will be around 300 mm in height only. Of course I could use Besser blocks  or bricks but I have heard about an adjustable galvanised steel system. It would consist of steel posts that I can fine tune to get the subframe at the exact height, The point being that my site is slightly sloping and it would be good to just be able to quickly level the thing up instead of fiddling around with bricks and then mortar layer on top (in the good old days we just put pieces of fibro).

Also,  Using short steel posts would be good for proofing against white ants/ Termites.

So here’s my question has anyone heard of a system of adjustable steel posts which I guess would be made out of Square hollow section or circular section galvanised steel with some sort of hole-and-pin system to be able to fine the height of the post. 

[EricL · Accepted solution]

Hello @hazzabatt

Welcome to the Bunnings Workshop community. It's awesome to have you join us, and thanks for sharing your question about adjustable steel posts for your deck.

The only product that comes to mind is the Uni-Pier 75 x 75 x 200mm Post With Adjustable Screw Top Head. This post comes in different lengths and can be adjusted for height. However, you'll need to use concrete footings to mount it as described in the brochure. Please make sure to check with your local council on the rules and regulations on using steel posts for your decking. 

Here is a link to the Uni-Pier Brochure: Uni-Pier Selection Guide

If you need further assistance, please let us know.

Eric

[hazzabatt]

Thank you for suggesting the uni post system. That was exactly what I had in mind. Only thing is I didn’t expect it to be in the order of $100 per post.

[EricL]

Hi @hazzabatt

I totally understand, I'm aware that you want the ease of installation, the strength of steel and extremely low maintenance. However, if the steel posts are outside of the budget, I suggest considering traditional 90x90 H4 treated timber. A single length of 90 x 90 will conservatively produce 3 posts. It might take you longer to install the posts but it will keep your deck affordable. 

Let me call on our experienced members @Adam_W and @MGusto for their recommendations.    

If you have any other questions we can help with, please let us know.

Eric 

[Adam_W]

Hi @hazzabatt , the adjustable steel posts are your best bet.

Yes, more expensive but as you pointed out they are termite resistant & also provide a bit of a termite barrier as white-ants don't like ravelling over such surfaces.
If you fraction time into the cost you'll find the steel is faster to install, rather than messing around trimming timber posts to height, so you save money in installation time.
Totally understand that it might not fit to budget however.
Remember too that to use timber you'll technically need to be still using concrete footings but they'll need stirrups embedded in them so cost difference isn't just in timber Vs steel. You need to include the stirrup cost (including a pair of M10 or M12 bolts & nuts)  for every post.

[MGusto]

Hi @hazzabatt 

I used the Buzon adjustable pedestal system to construct my deck. They are commercial grade and have very high load bearing strength. You could use the DPH-7 which adjusts from 285mm to 400mm and has a slope corrector in built. 

https://pasco.net.au/products/buzon-dph-7-adjustable-pedestal-from-285-400mm/

I am not sure of the cost but the smaller ones I purchased are quite cheap. You can view my post re my deck construction on this site.

Hope this is of some use.

Cheers

Mike

[hazzabatt]

Thank you for your suggestion regarding Pasco. I’ve left a voicemail to find out price and availability again many thanks.

[EricL]

Hello @hazzabatt

Just in case you want to see @MGusto's low-level deck assembly here is the link to the project - Low-profile deck with screening and steps.

If you have any other questions we can help with, please let us know.

Eric