How to restore Spotted Gum timber deck?

[LisaJ]

I am restoring my 8 year old timber deck, it was only last sanded and oiled a year ago but has a few black stains from the bbq mat/furniture, and wear from sun exposure that turn black when wet and are greenish when dry (see photos). It is a large area and 2/3 of the surface is in really good condition 

It is spotted gum and I intend to reoil.

I have tried prepping with intergrain ultraprep then deck clean, using a pressure washer. Then intergrain ultraprep mould killer. Now considering deck stripping then sanding but wondering if I can get away with just reoiling.

From Google research if i can't just reoil, my plan is to use a wood stripper (sodium hydroxide) and brightener (oxalic acid) then sand any remaining areas.

My questions are:

Can I just reoil the sun exposed areas ?

Suggestions on wood stripper and brightener brands/alternatives.

 

 sun exposed areas and bbq mat stain

If i need to sand do I need to sand the entire deck  even though most of the deck is OK?

If I only sand the sun exposed areas will that create uneven wear over time?

 most of deck in good condition 

 sun exposed area dry deck

steps in worst condition probably need sanding 

 

[LisaJ]

I tried re-oiling a small part of the sun exposed weathered deck boards

to see how they came up, they don't look awful, but darker and less colour than the better preserved boards.

I've decided to sand those areas

Can anyone recommend a sander? (Thinking belt sander)

I think I will buy one as I will probably need it again  in the future and can share it with my family 

[JacobZ]

Hi @LisaJ,

Apologies for the delay in response. It's fantastic to see you make your first post.

All the work you've done up to this point is great and you've clearly done your research. You've touched on all the ways to go about restoring your deck, so I'll try to steer you towards the best solution for your circumstance.

I'd suggest staying away from any chemical strippers unless absolutely necessary. Sanding is usually the best way to go. If there is still staining after sanding, you can address the stains on a case-by-case basis.

Ultimately, the best way to get an even coat is to sand back the entire deck and reapply the oil, however this is a lot of work. You should be fine just sanding the worst areas and then reoiling everything.

A belt sander is a great option when you need to do a lot of sanding, but they can be difficult to control and aren't so great for more detailed work. It is a good option for a deck, because they are flat and wide open, but it's less likely to get use in other situations. A random orbital sander is the best option in terms of versatility as it is lightweight and easy to manage while still being fairly powerful. Either of these options are good for this project, but a random orbital sander has a wider range of use than a belt sander. If you were going to make an investment in a sander, I'd suggest going with a random orbital sander over a belt sander.

Check out How To Choose A Sander for some further guidance.

Let me know if you have any further questions.

Jacob

[LisaJ]

Thanks for your very helpful reply at this very busy time of year, in response to my very long post (!!)

I will certainly check out the sander you have recommended.

Have a lovely Christmas 🎄 

[Jason]

Hi @LisaJ,

How large is your deck? 

I have a large Merbau deck and have sanded it a couple of times to bring it back to new. The first time was documented here - Deck renewal using floor sander. If your deck is a similar size I would consider hiring a larger tool to save your back. A small orbital sander would still be needed, but just for the edges and steps.   

Here's a comprehensive guide on How to sand a deck from the Bunnings team, which includes a video and a full list of tools and materials. You can see how they achieve a uniform colouring with fresh timber before proceeding.

All the best,

Jason