Problem with a deck

[Veren Pressure Cleaning 14]

I am not sure how this happened, but at I was cleaning the deck with EFC, these streaks started appearing (see below). The wierd part is that only the pressure treated boards came out like this. All of the cedar was fine. Is this tannin bleeds or some rust off of the nails? I tried to use citralic to fix the problem, but it didn't seem to do anything at all to it. Any suggestions?

[seymore 90]

The citric acid might not have been strong enough?? I've used oxalic to remove rust stains and and have had mixed results.The stains go away when the wood is wet and then show up again when the wood dries.

Try a stronger mix of brightner is about all you can do maby oxalic instead of citric.

So those are the cedar boards not PT right they look like cedar to me?

[bigchaz 157]

Had the happen on a deck earlier. If the brightener isnt rinsed well enough even though it will remove the rust stains when its wet the water just sits around the nail head. So once the water dries the streak is back. Try using a stronger mix of oxalic and rinsing well afterward.

Thats just my experiance, but I might be wrong

[Beth n Rod 1,279]

The fasteners are not Hot dipped Galvanized or coated to withstand the chemicals in the pressure treated wood. They are corroding and will continue to create the stain. Acid may exacerbate the problem by furthering the corrosion process.

The remedy is to remove the fasteners and replace them. The stains will not go away completely, but at that point they could be lightened.

I am sure the homeowner is not ready for the price tag on such an endeavor so take the time to explain it to them so they can understand why it will not go away. It is a pre-existing condition that you are not responsible for.

ie. you didn't put the nails/screws in the wood.

Rod!~

[MMI Enterprises 289]

Looks like pine to me...but so does everything else..lol...

..and yes I not doubt streaks that bad are likely to continue to leak out even after you get it with strong oxalic dilution on the outside. Even though chances are that most of the exasperating coating of the nails is corroded away it is all just sitting in the hole behind the nail heads all the way through and back and into the cross supports. Curing type stain might put down it coming back for awhile.. Might look good for a year or two and pass the customers expectations. Have to tell them though the job is a bust if they expect otherwise or want some warranty.

[James 625]

That's cedar. Stronger mix then use an oil like Ready Seal. It will stop the rusting for awhile.

[bigchaz 157]

I dont know anything about corroding metal but this pic shows both screws and nails. This is pressure treated. Spot treated it with oxalic and rinsed. Stained over with woodtux. I haven't seen the deck since it was done, but are yall saying the black will come back again even with stain over it?

[MMI Enterprises 289]

..new cedar easy to tell and smell..how to tell on old stuff..James? anyone?..links..lol..Actually meant to question maybe it be fir rather than pine or cedar.

ps.. wow that first pic blew up huge on my puter now..don't look treated whatever it is compared to Charlie's pt

[James 625]

Experience and millions of sq inches of cedar decks done. Look at the difference between the screw heads. No splits for one on the cedar wood and I can tell by the grain, color, size. shape and the Don knots.

You need to get oil around the scews to stop the rusting and tannin problems. It can be controlled not stopped.

[RPetry 564]

Kevin,

If you cannot tell by looking at the wood, see if you can "dent" the wood by sticking a fingernail into the surface. If it penetrates into the wood, its most likely cedar or possibly redwood. Cedar is much softer than PT pine or fir. Being from Ca., you should be able to recognize redwood by sight.

The fastener discoloring will eventually come back. This is the fault and responsibility of deck builders that use cheap fasteners on good wood.

[Beth n Rod 1,279]

That's pt lumber, no doubt.

Rod!~

[Beth n Rod 1,279]

Looks like PT to me too. :)

Beth :cup:

[MMI Enterprises 289]

"Being from Ca., you should be able to recognize redwood by sight."

ok..looks like very dried and faded sap redwood to me...haha :)

..psst..no really.. it does...lol..

[Beth n Rod 1,279]

You will laugh...but there is one other way to tell cedar for sure....smell. You will be able to smell the aroma of the wood, especially when wet.

Beth

[MMI Enterprises 289]

You will laugh...but there is one other way to tell cedar for sure....smell. You will be able to smell the aroma of the wood, especially when wet.

Beth

who'll laugh?. am I in the room?..Earth to Beth...thinks I mentioned smell already and there be an echo..lol..(hey yer right, i did laugh..haha)

[Beth n Rod 1,279]

Doh! So you did....

Beth

[James 625]

The first photo is cedar and the second it PT.

[Beth n Rod 1,279]

The first photo is cedar and the second it PT.

By George I think he's got it! ;)

Beth

[MMI Enterprises 289]

By George I think he's got it! ;)

Beth

No!..it's by James or Don Knotts I think he's got it! :)

[James 625]

Your guy's posts confused me after the PT photo.

[Beth n Rod 1,279]

I looked at the 2nd pic and made my determination. The handrails are showing pt, the floors are showing cedar.

Rod!~

[bigchaz 157]

I think you guys got confused when I put that pic up. Those are seperate decks. Mine is pt. I was just showing another example of that black effect around screws