Cleaning recommendations

[Don 0]

Good day, I have been reading through the posts on here and there is a ton of information, it has been quite interesting. I have a new PT deck that I just had built and I am going to wait 3 months and then use an AC Semi trans stain on it. From what I have read I will still need to wash and brighten it afterward. I was wondering what you guys would recommend as either a pre-bought product or one I can mix up at home. I plan on re-staining every 2 years or so but I am not sure if I should clean and brighten it every year or just clean it.

 

Thank you for any advice you guys and gals can give me.

 

Don

[Beth n Rod 1,279]

Since you are using Pt Pine, you can seal it within 2 weeks of installation according to the American Wood Preservers Association, the organization that
sets the guidelines for pressure treatment in wood.

If you are going to wait that long, your exterior environment will be a dictating factor on what you will need to do.
Oxy clean is easy enough for just gray wood and some mildew growth. Neutralizing with an acid is recommended.
I am not sure what stores you have in your neck of the woods but look for a product that has either Oxalic or Citric acid
and is designated for use on decks.
If you are looking for more specifics, try https://www.opwdecks.com/

If your deck environment has high moisture conditions from a pool, hot tub or pond/water feature or sits really close to the
ground and has little to no air passage beneath (less than 2' results in pockets of dead air and high moisture retention)
then you may have to look into an additional mildewcide to help stave off mold growth during the drying period which with
A/C can be anywhere from 2-5 days depending upon how much sun and shade you have. More sun, less dry time.

Rod

[Don 0]

13 hours ago, Beth n Rod said:

Since you are using Pt Pine, you can seal it within 2 weeks of installation according to the American Wood Preservers Association, the organization that
sets the guidelines for pressure treatment in wood.

If you are going to wait that long, your exterior environment will be a dictating factor on what you will need to do.
Oxy clean is easy enough for just gray wood and some mildew growth. Neutralizing with an acid is recommended.
I am not sure what stores you have in your neck of the woods but look for a product that has either Oxalic or Citric acid
and is designated for use on decks.
If you are looking for more specifics, try https://www.opwdecks.com/

If your deck environment has high moisture conditions from a pool, hot tub or pond/water feature or sits really close to the
ground and has little to no air passage beneath (less than 2' results in pockets of dead air and high moisture retention)
then you may have to look into an additional mildewcide to help stave off mold growth during the drying period which with
A/C can be anywhere from 2-5 days depending upon how much sun and shade you have. More sun, less dry time.

Rod

3

Thank you Rod. The deck has a 6x8 at 4ft and a 16 x18 at about 2ft and Ottawa is pretty humid here in the summer. I had read on the AC stain website that they recommended waiting 3 months that is why I was not sure. So if I am going to stain it about a month after it was installed I just need to do a light scrub with Oxiclean correct? Then next season if I am not restaining it can I scrub and brighten it or should I just scrub it? The lower deck was sealed off with flashing to keep animals out but I am going to look into seeing if there are some kind of vents I could install that would allow air to flow under the deck and not let animals in. It is closed off with cut down vertical deck boards so it would probably have to be a circle shaped vent.

 

Thank you for your assistance. 

[Beth n Rod 1,279]

Yes. Clean it first, wait till dry then apply. First coat on new wood is going to look much lighter than on older wood because the fibers are still
very tight and don't absorb as well as when loosened up by aging and lignin/extractives depreciation.

When you are to perform subsequent maintenance applications, clean with oxyclean if is it just mold. If algae develops, skip the oxyclean
and use bleach and water instead. (oxyclean and bleach don't get along in a mixture) Brush and then rinse thoroughly or use a power washer
to speed up the process but remember you aren't trying to remove the color. Some may anyway as there are no significant binders to hold it on
the surface and UV degradation will make it easy to remove.
Once clean, neutralize and rinse thoroughly and allow to dry. Re-apply A/C and if mildew is a problem in your environment, you can also use a small
amount of Japan Drier in Only What you think you can apply. Not the whole container. This will help the product set up faster and give less time for
nature to deposit things that promote mildew regrowth.

Yes, still use a mildewcide in only the new container you have. Not the used/partial one you may left over from prior applications.
Any remaining product (hopefully very little) should be disposed of once a drier has been added. The product loses its properties in the can
and when you go to use it later, it will not work as designed. This is why I state to only add it to what you think you will apply. If you need a little more
you can still add it to that amount required. Keep what comes in the can in the state it was once opened (except the mildewcide if you add it. That does not
hurt the formula).

Rod

[Don 0]

On 7/22/2018 at 8:36 AM, Beth n Rod said:

Yes. Clean it first, wait till dry then apply. First coat on new wood is going to look much lighter than on older wood because the fibers are still
very tight and don't absorb as well as when loosened up by aging and lignin/extractives depreciation.

When you are to perform subsequent maintenance applications, clean with oxyclean if is it just mold. If algae develops, skip the oxyclean
and use bleach and water instead. (oxyclean and bleach don't get along in a mixture) Brush and then rinse thoroughly or use a power washer
to speed up the process but remember you aren't trying to remove the color. Some may anyway as there are no significant binders to hold it on
the surface and UV degradation will make it easy to remove.
Once clean, neutralize and rinse thoroughly and allow to dry. Re-apply A/C and if mildew is a problem in your environment, you can also use a small
amount of Japan Drier in Only What you think you can apply. Not the whole container. This will help the product set up faster and give less time for
nature to deposit things that promote mildew regrowth.

Yes, still use a mildewcide in only the new container you have. Not the used/partial one you may left over from prior applications.
Any remaining product (hopefully very little) should be disposed of once a drier has been added. The product loses its properties in the can
and when you go to use it later, it will not work as designed. This is why I state to only add it to what you think you will apply. If you need a little more
you can still add it to that amount required. Keep what comes in the can in the state it was once opened (except the mildewcide if you add it. That does not
hurt the formula).

Rod

Thank you again for all this info Rod. One last question. Should I be rinsing with an oxalic Acid mixture after cleaning with the Sodium Percarbonate mixture?

 

Don

[Beth n Rod 1,279]

General practice after applying any product that is on the alkaline side is to apply a neutralizer.
While percarbonates become inert after they exhaust themselves, the pH is still alkaline. Stains/sealers
are designed to go onto wood that is in its neutral state which is acidic in nature.

Wash, rinse, neutralize, rinse.

Rod

[Don 0]

On 8/8/2018 at 6:51 AM, Beth n Rod said:

General practice after applying any product that is on the alkaline side is to apply a neutralizer.
While percarbonates become inert after they exhaust themselves, the pH is still alkaline. Stains/sealers
are designed to go onto wood that is in its neutral state which is acidic in nature.

Wash, rinse, neutralize, rinse.

Rod

 

Hi again Rod, so I bought a 25 degree green tip for the pressure washer and I washed the fence, it looked great but I guess I got a little to close since the cedar now looks a little hairy. I was not going to stain it because it is Cedar but if I sand it down a little to get rid of the hairs does that mean I have to stain? Also, would I still use 80 grit or is that just for preparing wood to be stained?  

 

Thank you again for all the help.

 

Don

[Beth n Rod 1,279]

Yes. No higher than 80 grit for outdoor surfaces. Better penetration.
60 is typical in our practice due to the buffing brushes we have in that grit.
This process also helps to lessen some of the un-eveness of coverage by furniture and other seldom moved items.

Staining (adding a pigmented sealer) is a preferrence. Also helps to stave of UV greying and degradation depending
on the opacity of the stain being applied. Toners-little opacity, semi-transparent stains-more opacity. Semi-solid greater
opacity and solids are totally opaque.
Clear sealers are in the vein of toners which have little to no opacity for UV protection regardless of what they state on
the label.

Rod