Deck cleaning help

[mrnewman3]

Hi All....

It's time to clean and seal/stain the PT deck. I have a fair amount of the green mold/algae funk growing on it. I need suggestions for cleaning it/killing it... I am not keen on using a pressure washer due to the damage they do to the wood. Also, I have lots of landscape plants around so chlorine bleach is out. Last year I used a bunch of OxiClean and a scrub brush. It worked reasonably well, but it was a complete PITA and required a huge amount of effort.

Has anyone used a power floor scrubber of any sort? I'm looking at cleaning about 800 SF...

Thanks....

[crokett]

If you are worried about your shrubs, borax will kill the mold and dooa lot less damage than a bleach solution. Borax is also a preventative and will soak int the wood and keep new junk from growing. You can get it at supermarkets or wally world.

[Hellrazor]

I use a pressure washer, simple green and a long handled brush.

[mrnewman3]

If you are worried about your shrubs, borax will kill the mold and dooa lot less damage than a bleach solution. Borax is also a preventative and will soak int the wood and keep new junk from growing. You can get it at supermarkets or wally world.

Thanks... I bought some and tried it on a smallish section. It worked pretty well... Still a fair amount of elbow grease as expected.

[TheRic]

You might want to try Clorox bleach in a spray bottle, will give you a little more control.

IMHO Borax is nice for mold, I have found that is works better as a preventer, than a killer. Clorox is better for killing mold. Even if you power wash the mold off, unless you get it all, it will come back. To get it all means getting into the wood (damaging the wood). Bleach lets will soak in a little and will do a better job than the power washer.

Borax, for best results, needs to soak into the wood, and should be coated several times. IT is dangerous if ingested (in large amounts) so don't let the dog / cat drink the puddles of water.

You might want to look into why you are getting all the mold. Preventing it from starting my be easier than stopping it once it starts.

[mrnewman3]

You might want to try Clorox bleach in a spray bottle, will give you a little more control.

IMHO Borax is nice for mold, I have found that is works better as a preventer, than a killer. Clorox is better for killing mold. Even if you power wash the mold off, unless you get it all, it will come back. To get it all means getting into the wood (damaging the wood). Bleach lets will soak in a little and will do a better job than the power washer.

Borax, for best results, needs to soak into the wood, and should be coated several times. IT is dangerous if ingested (in large amounts) so don't let the dog / cat drink the puddles of water.

You might want to look into why you are getting all the mold. Preventing it from starting my be easier than stopping it once it starts.

Bleach in a spray bottle is a decent idea.... I think I'll try that in addition to the cleaning..

I'm getting the mold for 3 reasons....

1. shade. parts of the deck are shaded and they are by far the worst.

2. when I went through this 2 years ago I didn't sufficiently kill it off before sealing... Now it is back, but to a much lesser degree.

3. I'm in Cincinnati. Humidity and shade are a nice combo.

Thanks...

[SARGE..g-47]

Morning mrnewman3...

Agree with the Ric on the bleach. I have a cedar sided home and plenty of trees for shade. Chlorox or have-ever ou spell it will take mildew off in a flash. I buy one of those garden sprayers and add 1 gallon to five of water. Pump it up.. spray it on a not too large area and wait about 3 or 4 minutes (not to long as the bleach will penetrate and damage wood fiber) and then throughly wash it off. The mildew will come with it.

You could cover your plants with cheap plastic tarp from the Box stores. You can use a regular garden hose to flush it but should use 2 gallons to 3 water to off-set the fact you have less water pressure than a pressure washer. But both ways work great. I use it in a spray bottle mixed with water on showers also. Just plenty of ventilation when you do. I used to try all of those store bought expensive things with hard scrubbing, but found the bleach is the easiest and quickest solution.

Regards...

Sarge.. jt

[mrnewman3]

Morning mrnewman3...

Agree with the Ric on the bleach. I have a cedar sided home and plenty of trees for shade. Chlorox or have-ever ou spell it will take mildew off in a flash. I buy one of those garden sprayers and add 1 gallon to five of water. Pump it up.. spray it on a not too large area and wait about 3 or 4 minutes (not to long as the bleach will penetrate and damage wood fiber) and then throughly wash it off. The mildew will come with it.

You could cover your plants with cheap plastic tarp from the Box stores. You can use a regular garden hose to flush it but should use 2 gallons to 3 water to off-set the fact you have less water pressure than a pressure washer. But both ways work great. I use it in a spray bottle mixed with water on showers also. Just plenty of ventilation when you do. I used to try all of those store bought expensive things with hard scrubbing, but found the bleach is the easiest and quickest solution.

Regards...

Sarge.. jt

I think I'll use a scrub brush and clean the surface then follow that with a little bleach and a thorough washing to kill the mold... Hopefully that will take care of the issue....

Thanks.....

[Cheeky]

Bleach in a spray bottle is a decent idea.... I think I'll try that in addition to the cleaning..

I'm getting the mold for 3 reasons....

1. shade. parts of the deck are shaded and they are by far the worst.

2. when I went through this 2 years ago I didn't sufficiently kill it off before sealing... Now it is back, but to a much lesser degree.

3. I'm in Cincinnati. Humidity and shade are a nice combo.

Thanks...

same here in NY. very humid and my shady clear cedar siding has to be scrubbed at least every other year, and then subsequently re-stained.

i've tried copoius additives to stains, etc., but in reality, nothing works. every 3 years or so, i have to scrub and re-stain the moldy sections.

[passlake]

Make the Bleach work for you

While I'm a complete woodworking n00b, I DO know water quality, and in this case, I have to agree that your best bet is to use a bleach solution. Now, to keep your plants safe and make the bleach do the work for you, as well as to avoid bleaching out your wood, you have to understand how bleach works to kill mold, plants (and bacteria).

Buy a pH testing kit (or borrow one from a friend with an aquarium or pool) and test your home water. If your water pH is between 5 and 7, you're in luck--when you add bleach to your water, you're going to end up with hypochlorous acid, the most effective means to rid yourself of your mold problem. If it's lower, you're going to have a higher concentration of dissolved chlorine gas, which won't do nearly as much good, and higher pH will give you mostly uncombined hypochlorite ion, which is 20-300 times less effective than hypochlorous acid at removing your problem.

Here's what you're going to want to do: use a FRESH bottle of bleach (the sodium hypochlorite that makes bleach, bleach breaks down quickly from light and exposure to air!), use just a quarter cup per half gallon of water. Wet the area to be treated, then let the bleach solution sit for 20 minutes, covered with plastic. When this time is up, most of the "chlorinates" in the bleach will have done their work. Rinse with fresh water. Scrub with a stiff-bristled brush--the mold should be, for the most part, dead. The runoff will be minimal, the chlorine will be used up, and you should not damage anything--your deck, your plants, or your lawn.

CAVEAT: Do not let this sit on your deck for more than 60 minutes (I recommend 20)...it won't do you any additional good. Rinse when you're done! Let the deck dry between applications if you choose to go at it twice. I live in Wisconsin and, again, I DO work with scientific labs with this stuff. Best of luck!