Deck - To sand, or not to sand..?

[Theremin]

We moved into our "new" house about 2 months ago. The house is about 90 years old. I have no idea how old the timber on the front deck is, what type of timber it is (other than it is hardwood) or what it has had on it in the past.

The timber is in good condition but it needs re-coating. I think I'll use Flood Spa-n-Deck. So, my question is what preparation should I do. Will the Flood PowerLift (or some other cleaner) be enough, or should I sand it? I've attached photos to give some idea of how it looks at the moment. The total area of the deck is about 25m2.

[jimj]

Dear Theremin,

Thanks for posting the photos. They tell the scenario perfectly. To return back to clean and bare timber you will need to sand the deck.Powerlift alone would not achieve the state you need to get this timber back to. I find on this type of decking I can usually start with 40 grit and I finish it with a 60 grit pad on a Sandivac. If 40 won't work then go to 24 then 40.This gives a nice smooth to the touch feel, not to slippery when the deck is wet from blow in rain and will allow the deck coating products to be absorbed into the wood. After the sanding is completed use the powerlift as it is a detergent based on sodium percarbonate. You can also achieve the cleaning with 200 grams Napisan mixed with 4 litres of WARM water as it is also 30% sodium percarbonate.. You will be amazed at the amount of dirt and oil it will lift from the newly sanded wood. Then follow with with Spa&Deck PREP (oxalic acid) This will slightly brighten your timber. After this you are ready to coat the deck with your preferred product. I have been using for the past 2 years Flood Spa&Deck acrylic wood finish. I would only recommend using either cedar or Sedona( walnut brown in colour). The natural is way to yellow to be pleasing. It is far from natural and the redwood, white and gray are not any better.

The most exciting part of your job will be when you have your deck sanded back and you have only fresh water on it. If it has that wow factor you are ready for coating. With the age of the timber you should see some magnificent grains and colours.

I live on the Sunshine coast. Please feel free to call me if you need any more info. If you look at my website portfolio all of the after photos are with Spa&Deck.

Good luck

jimj www.restore-a-deck.com.au

[Larry McCully]

I would definitly get it sanded back, i would not use just a polyvac, but rather i would get a pro in with a belt floor sander. the results will be crisper and the end result will be awsome. I have sanded back hundreds of them and with correct sanding they are a treat. finish of with 120 grit. If you are going to get it sanded, do not under any circumstance apply water to the uncoated timber.

[Theremin]

Thanks for the advice guys. I will get it sanded and hopefully post up some pics once it's done.

If you are going to get it sanded, do not under any circumstance apply water to the uncoated timber.

But Spa-n-Deck is supposed to go on with the timber wet. So how does that work??

[jimj]

I guess I didn't explain the sanding as clearly as I could have. When I meant to sand with 24 and then 40 I meant with a belt sander. I too like Larry own a Lagler hummel. He has a 12 1nch belt machine I own the 8 inch Lagler. I use the belt machine for the initial aggressive sanding but once I get the deck back to a clean 40 I can either go to a 60 belt or a 60 pad on my Sandivac to finish. I find that 60 is as smooth as I feel it needs and I guess if you want to go higher that is a user choice. It depends. Where I would differ with Larry is with the water on the timber. I always wash the deck with sodium percarbonate based product to release as much of the dirt as possible. On internal hardwood floors this wouldn't work but I havn't had any issues at all with regards to the cleaning of the decks. On new decking timber it is recommended to let it weather for 3-4 months to let as much of the oils and tannins leach out and the more rain the better. When it comes time to coat the new wood we still use the detergent with a highpressure water cleaner.
With all due respect, Larry has offered the highest of great information on this forum and has been a most willing contributor. I took Larrys advice from a earlier posting regarding dome headed nails and whether or not they can be punched. Once I read that he punches them to allow for sanding I thought great. I then went out and researched sanding machines and settled with the Lagler hummel. It was some 12 months later that he wrote that he uses the bigger model of the machine. ( the thought of carrying anything that big up and down 20 steps makes me feel tired).So thanks Larry that was great advice. I havnt done hundreds of decks but have done 60 over the past 2 years , all washed after sanding and the first coat of Flood spa&deck must be put down on a deck that has been saturated with water. It is the product that I have been using up here as it is a product that can handle the baking sun of the Sunshine coast. Over the 2 years I am pleased that I have had no callbacks from past customers. I could list the products that I have cleaned off decks that were supposedly the ultimate but I don't want to risk defamation. I am really rapt that Flood have released a 2 year guarantee against cracking, peeling or blistering and I know it won;t turn black provided it is put down following the instructions which is to clean the deck first whether new or old.
Theremin, I would agree with Larry that you may be wise to have someone who can sand well and hire them. The rental drum sanders can cause more damage and hassles. Even after you sand out the main body you still have to trim out the edges. I own a Lagler Elan which is a hand held sander for edges but mostly use a Festool RAS 115 and clean up the edges with a Festtol Rotex 150. All of this gear is fairly pricey and would probably be easier to hire someone.

Best of luck

Jim J www.restore-a-deck.com.au