Should I sand back my deck before oiling?

[Lockmc]

Hi all.

I have 3 decks of different sizes that I've neglected for a few years. I want to give them some attention, sand them back (if needed) and give them a clean and oil.

First deck is my main deck.. has had an oil a few years ago but is greyed off in areas that get sun and starting to cup. I've also spilt paint in various spots. About 40sqm.

Another deck is my spa.. never had any oil on it. About 4sqm.

And last deck is my front deck.. was oiled a few years ago. Seems to be getting dirty in the exposed area. About 7sqm.

   

What I'm wanting to know is if I need to sand these back before oiling? And if so, what sort of effort are we talking? I would hire a sander to do it. Are we talking a day? 2 days? Is it painful work to sand it back?

And would you recommend I clean it first with something?

[JacobZ]

Hi @Lockmc,

Thank you for your question about sanding your deck.

Yes, sanding your decks will make a big difference, especially since they have uneven wear. If you were to clean and reoil them as they stand, it would be uneven across the different wear areas.

For your main deck, a full sand-back is the best option to bring everything back to a clean slate and even out the different wear patterns. It’ll remove the grey surface, flatten cupped boards, and strip off any paint, giving you a clean base for oiling.

The other two decks are quite weathered, and they would also benefit from a good sand before oiling. This will ensure the grey weathered timber is removed and you don't have irregularities because of it.

Before sanding, you'll want to give your deck a good clean to ensure you are not sanding dirt and other contaminants deeper into the timber. Check out How To Clean a Deck for some guidance.

For the sanding process, you can hire and use an Orbital Floor Sander for the majority of the work and use a random orbital sander for edges and tight spots.

You should allow a full weekend for the process. Sanding will likely take a full day with cleaning and oiling taking a few hours each. It can be a bit taxing on your body, as any physical labour is, but if you are steady, drink plenty of water and listen to your body and take breaks when needed, it is certainly achievable. 

I'd suggest having a look at How To Sand A Deck and How To Oil Your Deck for further guidance.

If you have further questions about the process, please don't hesitate to ask.

Jacob