Deck cleaning

[davec]

Hi all, I am getting near completion of my deck I have used 90x19 kapur & am using cabots deck oil.The cabots people recommend cleaning the deck with their deck clean product before oiling.is this really necessary as the timber is smooth & appears to be clean.any suggestions or past experiences appreciated.
regards dave.

[Gumby]

I used Feast & Watson decking oil on my new deck which is Merbu. They also recommended their own cleaning stuff first but i just put on 3 coats of the oil and it's come up great. I gave it a good wipe over first, just to get the dirt off. Just watch that you don't put too much on in one hit and wipe off the excess after an hour or so. Otherwise it stays sticky for weeks.

[jimj]

Dear Dave,

I am in the business of cleaning back the crud on people'e timber decks and putting new coatings down on the Sunshine coast SE Qld. There are many variables in this timber finishishing game. Most of the literature from most of the companies recommend leaving the deck to weather and allow any oils or tannis to leach out on to the surface. If you are absolutely certain that all oils are out and when the timber is sold as seasoned or kiln dried I think it is still a little of buyer beware. If you coat it with any product too soon it MAY still have some oils work their way to the surface and ruin the look of your new deck coating with black blotches. The steps that I do are as follows. 1. Let it age for 12 weeks hosing it off weekly trying to draw out any existing oils. 2. When I am ready to Coat I soak the deck with water and spray a coating of a alkaline type detergent which is based on the chemical sodiun percarbonate. Leave it on the surface for 20-30 minutes to work. you will be amazed at the dirt this will bring to the surface. I have a specialised scrubbing machine from Austria worth 5000.00 so I doubt that you would be buying one. However Bunnings has just put a smaller version of the machine in their stores to hire for scrubbing tiles. It is yellow and called Rotowash and will scrub a lot better than you can by hand. Make sure you always keep the deck wet and really rinse off the soap. I then lay down a mixture of 50-50 oxalic acid and water on the wet deck for a further 20-30 minutes and then scrub. This will help in bringing the timber PH back to 7, brightens up the wood more and opens the pores up in the wood to allow better penetration of the product. Again wash off all residue of the Oxalic acid solution. The aim is to not let these cleaners dry out on your deck. I try to avoid the heat of the day and if your deck is big break the cleaning down into smaller areas. If you are laying down any oil product let it dry for a good3-4 days before coating. I am using Flood Spa&Deck which goes straight on to wet wood with the first coat. Sodium percarbonate is really what Nappy san is. I use it already made up from Flood called Powerlift. It will really make a good job turn out much better as you will really pull ou a lot of dirt that is impregnated in the wood.

Good luck!

[Larry McCully]

IF you have the time and cash..... you will get the best esults if you get a pro floorsander in and get him to sand it to a 100 grit finish and then polyvac it with a 150 grit. You coat it , it doesnt cost much to do a sand only , and the results are perfect, you will not regret spending the $. punch down all the nails first and you will even get it done cheaper. Do not putty up the holes, use a flooring punch and sink thee nails down at least 3-4mm. I am not saying that chem wash on decks is not good, I just know yhat sanding of them is heaps better. The reason is that you expose the grain when you sand it. when you chem wash all you do is clean it. There are some beautifull swirls and tectures in you timber deck. tThat is why you put it in in the first place.Use a good quality deck oil, feast watson . you will love it.

[jimj]

I would agree with the sanding method if all things are equal. The problem that I am finding on the Sunshine Coast outside decks is that 2out of 3 decks have been fixed with a galvanised or stainless steel dome headed twist nail 50x2.8g. I haven't seen any one successfully punch thses down even flush with the deck let alone 3-4 mm. The other aspect is that if you do punch down that far instead of leaving them flush they will overtime fill up with water and dirt if exposed to the weather and adding to the decay around the holes.. The best nail from all of my readings seems to be a galvanised bullet head 50x2.8g hand driven to flush with the deck surface. I am constantly having to remove broken down sikkens type film coatings on decks with 450 mm spacings of dome headed nails which sit above the surface. In this entire game of outside deck building versus maintenance it seems like every time you take two steps forward you go back a step. The machine that I scrub with will allow me to with the grain and across the grain with no damage. Many of the decks that I woprk on or also badly cupped and by scrubbing across the timber my two roller brushes drop perfectly into the bottom of each cupped board pulling out the dirt. This will not be the problem on Dave's deck but he didn't state what type of nails he has used. I hope for his ultimate ease of maintenance he used either bullet head or better yet stainless steel screws countersunk.

[Larry McCully]

IT is succesfull to punch down those s/s dome heads, we did one 3 weeks ago with no problem. sikkens dwd is fine to use but tung oil besed coatings penertrate into the timber and not sit on top. i have never seen water and grime build up at the nail head enough to warrant any concern, every thing dries out when the sun comes out. i have seen cleaned decks and i have seen sanded decks, and i know which one i would choose.

[jimj]

Larry,

I have no doubt that you may have been able to punch SS dome headed nails down .Are you equally confident about Galvanised dome headed? I am not trying to argue. Both systems have their place. I am a true devotee to sanding as always the first method but when you are dealing with galvanised domeheaded which outnumber SS dome headed up here at the Sunshine Coast by 5-1 what other choice do people have? Galanised nails don't like to be sanded at all. I hope for Daves sake that he can punch down his nails to allow for sanding but if he can't then it is just coat now and be done with it or try another approach to clean the timber back the best way he can and achieve the best job that he is pleased with. Everyday we learn more methods and concepts. Daves question was should he clean back the timber or just coat now. I would recommend to let it age for at least 12 weeks and then either sand if he can or scrub it back by cleaning.

[davec]

Thanks for the advice you guys!Fantastic response,I will post some before & after photos in a few weeks,Cheers.

[McBrain]

I too am just about to lay the deck boards (merbau) on my new deck.

I am finding that finish of the new boards is quite variable. Different colours and roughnesses.

Also there are stains on a few of them, the stains seem to be quite sticky - is this the oils coming out of the timber, or would it be from something getting on the wood during storage?

Is there something quick I can do to brink them up BEFORE I nail them down? Scrub them with detergent, sand them (would be a pain - there is a lot), etc?

I will be using dome head gal nails to fix the boards.

Assuming that there is some way that I can clean the boards up before fixing, would the general advice be to nail down the boards and then leave them for 12 weeks before oiling? What would be the problem with oiling them straight away?

I want the deck to come up nice, but I've already spent a lot of time and money - I want to get it done!

Cheers.

[Larry McCully]

That is correct in what you say, I have punched down both types of nails, galv and ss. It is inportant that they are sunk at least 4mm below. I grew up in townsville on the coast of north qld and sanded floors and decks all down the coast of qld, as well as hammilton island , with the last 3 years in fortitude valley working on floors in GC and SC. The deck does need to in place for that period of time before any finish work is done , as you have stated. I just lke the look of a freshly sanded deck, the grain is enhanced. Then with the coating ...mmmmmmmmmmmmmmmmm!

[davec]

Mcbrain,I found that there was also a lot of colour difference with the Kapur that ive used,as I have 55sqm of deck I just could not afford to ditch any pieces so i randomly added the odd colour pieces and supprisingly it looks good,it even adds a bit of character to the deck.
Some lengths of the timber were a real yellow color so if these were long lengths I would cut them & use them in small lenghts at the end of a run where they were not as noticable.

[McBrain]

Thanks for the reply Davec.

Yes, I quite like the different colours too.

I found that the stains came out. The boards were sitting outside in the rain and the water sitting on the surface seemed to lift out some of the oil and became a brown colour. When I sponged-down the boards this made the colour a lot more uniform over each board with no blotches.

We'll see how it comes up when I oil it.

Cheers