How to treat new Blackbutt deck timber?

[Bunnybill]

I am having pre-oiled Bunnings blackbutt timber installed on my deck. Do I need to apply another coat 8-12 weeks after it has been laid? What product has been applied in the pre-oiling and should I apply a clear oil or one that has a colour additive mixed in with it? Cheers, Bill

[MitchellMc]

Welcome to the Bunnings Workshop community @Bunnybill. It's a pleasure to have you join us, and many thanks for your question on coating decking.

Yes, you should wait several weeks for the current coating to age slightly before applying your new coat of oil. You can either use an oil-based oil or a water-based product. Typically, on a new deck, you would just use the natural version with no additional coloured tinting. If in a few years the colour of your deck begins to fade, you can then switch to the colourant version to rejuvenate it.

Here's a helpful guide: How to oil your deck.

Please let me know if you have any questions.

Mitchell

[Bunnybill]

Hi Mitchell,

Thank you for the information about oiling blackbutt timber. Do you know if the oil used by Bunnings for pre-oiled blacbutt (Universal Intergrain) has an additive mixed in it? Our builder has used Bunnings pre-oiled blacbutt on our deck but discovered he needs to get more to do the face boards. Unfortunately he can’t get any of the pre-oiled boards from Bunnings here on the Central Coast and asked me to get the oil which he’ll apply to the raw timber.

Cheers,

Bill

[MitchellMc]

Hi @Bunnybill,

When you're referencing an additive, would that be the stain tint or colourant? To the best of my knowledge, the Intergrain product would be the natural version with no tint added. As above, you typically would only use a clear oil on new timber. Always best to check on a test section before committing to the whole deck.

Mitchell

[Bunnybill]

Hi Mitchell, We have just had Bunnings pre-oiled blackbutt timber laid on our rebuilt deck by a licensed builder. On many of the boards there are 5cm wide strips of discolouration. Do you know what could have caused them? And what can we do about it? Thanks, Bill.

[JacobZ]

Hi @Bunnybill,

I'm not entirely sure what caused it, but it appears to be watermarks. The marks appear fairly uniform, so I suspect they could be from timber gluts that the decking boards were sitting on or from packaging of some kind.

I wouldn't be too concerned; a light sand with some 120-grit sandpaper should remove them fairly easily.

Give this a try and let me know how you go. I am happy to help further if required.

Jacob

[Bunnybill]

Hi Jacob,

If I sand the waterstains will I then have to sand the entire board to maintain a uniform appearance?
Bill

[JacobZ]

Hi @Bunnybill,

You wouldn't need to sand everything, but you may need to sand a little bit past the area to blend it in with the surroundings. Once you've applied the clear oil you mentioned above, it should blend in well.

If you wanted, you could try using Cabot's 1L Deck Clean before sanding to see if that removes the watermarks. If successful, you might be able avoid sanding at all.

Let me know what you think.

Jacob

[Bunnybill]

Thanks Jacob. I think I’ll try the Cabots cleaning product first.