Can you use treated Pine as fence posts?

[rcam47]

I am wondering if treated pine 70 x 35 mm posts can be set in concrete as a frame to allow climbing plants to screen the fence. They say treated pine is only for above ground work.

[MitchellMc]

Welcome to the Bunnings Workshop community @rcam47. It's great to have you join us, and many thanks for your question about treated pine.

That product is rated H3 for aboveground use. You could paint the end going in the ground with Bondall 1L Inground Timber Protector, which would add to the lifespan of the timber. You need H4 timber for in-ground, and you'll generally find it in post sizes. Alternatively, you could concrete in a half stirrup post support and then bolt your H3 70 x 35 to it.

Please let me know if you have any questions.

Mitchell

[rcam47]

Thanks for your reply 👍

[jacksumit]

Is it beneficial to use Bondall Inground Timber Protector  on H4 treated Pine post as well or that is not required?

[MitchellMc]

Hi @jacksumit,

The treatment used on H4 Pine posts makes them suitable for in-ground use, and no additional treatment is needed for prolonged life. However, if there are drainage issues and the posts are going to experience extended periods of time in water-saturated soil, then it could be a good idea to paint the in-ground sections with Bondall 1L Inground Timber Protector. It will increase the life of the timber in below ground applications by sealing the H4 treatment in and keeping moisture out.

Please let me know if you have any questions.

Mitchell