What timber to use for formwork for concrete edging?

[ColinL]

Hi I'm trying to follow this video guide below to make a curved formwork for a new concrete edging in the garden but I'm struggling to find a soft timber (sheet?) that can be curved like the one in this video. The edging will be about 10 metres long. A basic timber will do as I'll probably recycle it after the border when completed, can anyone please link the product from Bunnings? Thank you.

https://www.bunnings.com.au/diy-advice/building-construction/cement-concrete/how-to-build-formwork

[Jason]

Hi @ColinL,

Let me tag @Adam_W and @tom_builds to see how they would tackle this project. 

I'm sure @EricL will also be happy to assist as soon as possible.

Thanks for your patience,

Jason

[Adam_W]

Hi @ColinL 
I reckon I'd just use some treated pine garden edging as it's reasonably flexible & cheap enough.
If you need curves beyond what it naturally wants to do then the trick is to use a power-saw to make a series of cuts around 1/3 or 1/2 of the way through the timber from side to side about 10mm apart on what will be the outside of the form-work around the area the curve is needed.
The cut depth can be a little tricky as it varies with the timber so you may need to play around first but again, the stuff is cheap enough to be able to do that.
You'll likely need to make sure you use lots of stakes through the curve to guide it accurately.
Very quick diagram...

[Noyade]

"The edging will be about 10 metres long."

Maybe extravagant - but I've used thin plate steel as formwork on large curves.

[ColinL]

Thanks @Adam_W, the link you provided said thr page cannot be found, do you mind linking through product again?

Thanks for your help, appreciate it.

[Adam_W]

That's odd @ColinL , maybe try a different browser?
Here's the link in full & a screenshot for good measure too

https://www.bunnings.com.au/100-x-16mm-4-8m-edging-h4-treated-pine-sawn-wet_p0120829

And a tip from experience... If you're looking for something in-store that you've found on-line write down the item number ( I/N ) from the web-page & ask a team member about it's location. In my experience stuff can hide in unexpected locations in different stores due to size & layout differences.

[ColinL]

Awesome thank you very much Adam!

[EricL]

Hello @ColinL

It's great that you've received excellent advice from @Noyade and @Adam_W. Just to add more options, you can also use Saxon 150mm x 10m Black Garden Edge. I also suggest using 2440 x 1220mm 3mm Plywood Pine Premium BC Grade. You can cut it into 100mm strips and you get 12 strips that are 2.4 meters long. 

Please keep us updated with your progress, we look forward to seeing your concrete edging complete.

If you need further assistance, please let us know.

Eric

[ColinL]

Thanks heaps @EricL - I do have quite a few rolls of those Saxon garden edge which is what I'm trying to replace with concrete edging. Are you suggesting that I can use them as formwork because they're much easier to bend? That could be a pretty good idea! Except it is hard to maintain perfectly straight as it is too curly, I could try to use more stakes to keep it as straight as I can? 

Thanks,

Colin

[EricL]

Hello @ColinL

The Saxon 150mm x 10m Black Garden Edge can be used for formwork. However, it must have enough stakes to hold its form. I recommend using timber for the straight runs. It will be difficult to keep the garden edging straight because of its construction. My overall suggestion would be to use both mediums to finish your project. Use garden edging for the twists, bends, and turns. Use timber for the straight runs.

If you need more advice or information, please let us know.

Eric