How to install a front timber post fence?

[bow2021]

Hi there,

looking to install a front fence. We liked the idea of white painted timber posts the whole way along with nothing attached like the picture added

 

looking for guidance on what timber to use. Was thinking of 90x90mm posts but wanted them not to be too rough, do you have to buy Dressed timber? Would h4 pine be ok?  Also thought would smaller timber work as well without it getting warped to save on money like 90x45?

any advice would be greatly appreciated. Thank you. 

[MitchellMc]

Hi @bow2021,

If you’re aiming for a clean, painted look like in the image, then using dressed timber—what’s known as DAR (Dressed All Round)—is the way to go. It’ll save you a lot of time and effort in sanding and give you a much smoother finish for painting. Just make sure the timber you choose is H4 treated if it’s going into the ground, as this treatment is specifically rated for in-ground use and will resist rot and termite attack.

The size of the posts is also important. While 90 x 90mm H4 posts can certainly work for a front fence, keep in mind they may still experience some twisting or warping over time, especially if they’re tall or exposed to strong sun and weather. Even kiln-dried, treated pine (like 88 x 88mm F7 H4 KD) can sometimes move a little. The posts in your image look quite substantial—probably closer to 150 x 150mm hardwood, which gives them that strong, architectural presence and helps keep them dead straight over time.

As for smaller sizes like 90 x 45mm, unfortunately, they wouldn’t be suitable for this kind of vertical, standalone installation. They simply don’t have the rigidity to stay upright without bowing or twisting.

So, if you’re going for that bold, minimalist style with posts only and no rails or infill panels, I’d recommend sticking to at least 90 x 90mm H4 dressed pine. If budget allows and you really want them to stay true and straight, consider going up to a larger post size or even hardwood. And of course, proper installation—including a good depth of concrete footing—will make all the difference in helping them last. 

Please let me know if you have any questions.

Mitchell

[bow2021]

Thanks @MitchellMc this is really helpful. 

just a couple of follow up questions. If we was to use hardwood, what kind of hardwood is available and you would recommend to use?

Is cypress pine like this an option https://www.bunnings.com.au/90-x-90mm-3-0m-post-f7-cypress-dar_p8032631

not sure if this is treated or not or if cypress needs to be treated?

we did see some inspo that looked like thinner metal rods that Could achieve the same look is that an option? Do Bunnings have white steel fence posts? 

[MitchellMc]

Cypress pine is quite resistant to decay @bow2021, however, I would suggest coating the portion used in the ground with bitumen paint to help prevent the early onset of decay. 

Hardwood-wise, we have the 90 x 90mm 2.4m Post GL17 Pre-Oiled Merbau DAR and larger sizes available via Special Orders. As this is a laminated (glued together) post, I would be hesitant to recommend its use in-ground.

Mitchell