Look at this One! Yiiiiiiiiiiiiiiiikes!

[fireandrain]

I landed this project today, redwood deck/trellis/fence. Never seen redwood so covered with Lichen! Wondering about my best shot with this, concerned about ripping up those small 1x2 top slats tryin to get that lichen and fungus off. HO said she had the deck put in 10 yrs ago (hmmmm 10?) and never had anything done to it since.

Is it time to dig out the 5% bleach? Dwell time gonna loosen it up ya think? Curious...

[4000psi]

Now thats where you would say Yikers!!

[RPetry]

Matt,

That is bad. Problem is, redwood is kind of soft in constitution. We don't see it much here on the East coast.

Worst I have seen was on an old PT deck. This stuff was like it was baked on, in layers, when dry, hard as coral. Took 8 oz./gal. of NaOH and a half hr. of dwell to loosen it up to a point it could be pressure washed off. Did not try bleach as most of it was dead or even calcified.

Good luck. The problem with cedar and redwood is that it cannot take that much pressure.

[CarolinaProWash]

Rick - did you find that once the crusty was off that the wood was actually in nice shape? That was our experience on a dock we worked on.....looked like absolute hell when we estimated and cleaned up unbelievably well.....like the crust had protected the wood actually.

Celeste

[bigchaz]

all those fancy looking plants are gonna take a beating with the chem youll need to clean that wood

[fireandrain]

Originally Posted by RPetry

Matt,
Took 8 oz./gal. of NaOH and a half hr. of dwell to loosen it up to a point it could be pressure washed off. Did not try bleach as most of it was dead or even calcified.

Rick, a fair amount of that old lichen is still alive, much of it did Im guessing. Do you still think NAOH is going to be the way to go? I suppose, worst case scenerio, those top 'bender board' 1x's could be replaced if the wood can't handle the beating...

[MMI Enterprises]

I don't think so. It may come right off without extreme measures. Just a matter of getting it wet through and through with surfactant as the gray that is surely underneith will give it all up rather easy. Some butyl or tsp along with percarb should do. Covering them plants might be sound advice though..

This was just with garden hose in a somewhat controled acidified bleach experiment. Not nearly as thick as what you got Matt but it just goes to show how weak the stuff can be to get off:


Although not same gross buildup this deck did fine with boosted NaOH and didn't kill any flowers or plants that were overgrown all over the railngs.The first pic is the test section with garden hose and I ended up diluting about half during actual job. The stair rails looked same as Ricks pic:

[fireandrain]

nice one Kevin. I have some straight sod. percarb, thinking of soaking the heck out of it, then ds'ing straight sod. percarb..... adding some tsp sounds great, how much? ive never boosted straight sod percarb w/ TSP... Ive generally sprayed straight percarb w/ simple cherry, will adding the tsp be any harder on surrounding plants?

[RPetry]

Originally Posted by CPW

Rick - did you find that once the crusty was off that the wood was actually in nice shape? That was our experience on a dock we worked on.....looked like absolute hell when we estimated and cleaned up unbelievably well.....like the crust had protected the wood actually.

Celeste

Celeste,

Yes, same here. This was an old, very neglected PT deck. Wood areas without the calcified crud did look more degraded than the "crudded" ones. Whatever it was, it was tough to remove. Needed more water pressure than usual for wood.

Rick, a fair amount of that old lichen is still alive, much of it did Im guessing. Do you still think NAOH is going to be the way to go?

Matt,

If its the same stuff we faced, yes. Tried a non-boosted sodium percarb cleaner at 8 oz./gal. with a long dwell, but it was not very effective. This job was a few yrs. ago, and from what I can remember, we still had to "blast" it off with pressure. Way more than you could hope to use on redwood.

Agitating NaOH or a percarb with a stainless steel pool brush and re-wetting might be helpful. Good luck!

[Beth n Rod]

Eeeeewwwww!!!!
Wow!
Beth

[Beth n Rod]

That looks like something off of "the Flying Dutchman" in Pirates of the Caribbean! Crusty!!!!

I would hit is with a 20/80 bleach/water solution to get rid of the algae, then go back and hit it again with your regular deck cleaning solution. I have had to do some monsters like this in the past and it is the quickest way to get through all the crustiness.
Good pic.

Rod!~

[fireandrain]

Originally Posted by Beth n Rod

That looks like something off of "the Flying Dutchman" in Pirates of the Caribbean! Crusty!!!!
Rod!~

LOL, sure does! I've had success in the past with a HEAVY SOAK/DWELL bleach h20 approach. As I mentioned before, my concern is that Im going to have to blast those top 1x2 slats to get the last of the lichen of of there, may need to replace those~ bender bds. Hope not. Im actually really looking forward to this one! I built in plenty of 'lab time' on this one (definition of "lab time"= me gazing up a the trellis with my pw growling behind me, lance in hand, scratching my head). The setting for this deck/fence/trellis is really wonderful, great back lot, very nice client. She is going to be up in Lake Tahoe the week I'll be tackling her project so I really want to blow her mind when she returns. Planning on spraying this with RS Med Red (redwood only).

[MudDuck]

Looks like someone built that down in a peetree dish. That house and roof looks like a great upsale when she comes back and see's how nice things are SUPOSED to look like. Make that sucka "bling gleem" and she'll have no choice but to have you do EVERYTHING else. lol Gotta love that. Also you stated that was 10 yrs worth? Maint plan should be a "gimmie" on that HO.

[fireandrain]

Originally Posted by MudDuck

she'll have no choice but to have you do EVERYTHING else. lol Gotta love that.

Great thing is that shes preparing the house for possible sale in the next 6 months. In this area, $1.5 mil. property. I agree, if she likes the outcome, may be more in store.

[Tegrey]

Ugly fence, No Problem.