Mildew

[csoldier]

We have had 2 incidences recently in which we pressure washed painted wood surfaces on houses to remove mildew, and the mildew returned with a vengeance within a few weeks. The mixture we use is Chlorox and liquid Tide. I was informed by someone that Tide could promote mildew growth. Any info on this.? This is very frustrating to us because no one we speak with can tell us the problem. The house is totalyl cleaned when we leave. I live in a very hot and humid area(N.O., La.) which I know promotes mildew growth. But in these cases, the mildew returned and was worse than before we cleaned it. I have recleaned at no charge to the customer, but this is costing us money and makes us look incompetent. Please share some advice with us and what type of mixtures do you use? What type of surfactants?
Thanks and God bless!!!!!!!
Mark, La.

 

[ron]

Hi you are useing Tide? i used to use some tide for the phousphous[spelling?] and some cleaning but home depot sells it by the box.
The tide is made to NOT FOAM UP. If it did you would have suds all over the place.[your washing machine]
YOU WANT SUDS-IT MAKES THE BLEACH STICK use the NEW DAWN with the bleach and let it dwell[sit] on longer.
you might try a liquid wax with some bleach in it as a rinse[keep it off the windows
[dont do this if they are going to paint anytime soon] the slicker the surface the less chance the mold spores have to get a grip. hope this helps
This is one of the few cleaning surfaces you want high suds ive even used westleys wash and wax/bleach on plastic siding cleans-shines-protects-and keeps it slippery so the mold cant get a hold its made to rinse off easy and is biodegradeable

 

[Richard R.]

csoilder,

First off, I've never heard of mold and mildew coming back that fast.
Ron sounds like he has a good idea though.
One other possibility you may try, depending on the paint and surface.
I'm just wondering if your making sure your bleach has the sodium hydroxide in it. Kind of a micro clean if you will. Ultra Clorox makes a very THICK bleach called Ultra Clorox Advantage. It hangs on to the surface a little longer so it can work hand in hand with the hydroxide.
Also check the area in which the mold is coming back in. If the area does not have good ventilation, chances are it will grow back much quicker. You may have to suggest some clearing and cutting back of trees, fences etc....
One other thing, I'm wondering if it would hurt to finish your job by spraying a very lite mist of bleach on the surface. I don't know if that would stain the surface or not.

Hope it works out OK.

Richard R.

 

[sprayandclean]

mildew bloom

WHAT YOU HAD HAPPEN IS REFERED TO AS A 'MILDEW BLOOM'. tHIS OCCURS DUE TO THE HEAT AND HUMIDITY YOU HAVE EXPERIENCED IN CONJUNCTION WITH THE WIND BRINGING IN A LOT OF THE BACTERIA THAT CAUSES THE FORMATION OF THE DARK RESIDUE WE REFER TO AS MILDEW.

i HAVE HAD THIS HAPPEN TWICE IN 10 YEARS, BOTH TIMES ON PAINTED WOOD EXTERIORS.

YOU SAY YOU ARE USING CLOROX...SODIUM HYPOCHLORITE...
DID YOU RINSE?

NOT RINSING LEAVES A TRACE FILM OF SODIUM, WHICH ATTRACTS MOISTURE, AND HASTENS THE GROWTH OF MILDEW.

A HOTT WOTER RINSE WORKS BEST, BUT IF ALL YOU HAVE IS COLD, PUT ON THAT ZERO DEGREE SOAP TIP ((#40), UNHITH THE SOAP INJECTOR AND FLOOD THE HOUSE.

GOOD LUCK,
BATES

 

[gasman]

Your not removing the mildew. Your bleach is just whiteing out the mildew not removing it. You have to brush or use a high pressure fan spray a few inches off the surface and go over every square inch of these houses. Some think just spraying bleach on houses is cleaning, but I disagree.

 

[Richard R.]

You may be right to an extent, but I will have to disagree in the most part. The Chemical Hypochorite (bleach) actually kills the growth which is the mold and mildew. When this occurs, the growth deteriorates in a disintegrating fashion. Since Mold and Mildew is sometimes a green, black white and a yellow growth, and your theory is that bleach is a whitening agent , this would only mean that the application of bleach on Mold and Mildew growth would result in white spots all over your surface. If you will notice, everything turns back to the original base color which tends to make me believe the mold spores disappeared. In other words, if you spill bleach on a red T-shirt that was originally white, the red dye disintegrates just like the mold and mildew does. What you see coming off of a surface is usually dirt or other types of foriegn matter which was lifted by the surfactant and removed by force of your rinsing agent such as water, brushing etc...

Bates,
No disrespect to either one of you, but I would like to know your information source. This may help me to understand a little more about this growth.
I'm somewhat confused. Sodium is a deterrent to moisture.
The best means to prevent or control the spread of microorganism growth (mold and mildew) is to deny the spores the moisture necessary for germination. Therefore, regulating the environment, especially the RH, is essential for preventing the deterioration of a museum collection from microorganism growth.
Sodium dehydrates which means to remove water or make anhydrous. To confuse things a little more, there is a product on the market called Damp Rid, which is known to be the leading agent to prevent mold and mildew in homes and buildings. It appears to be a bucket full of crystalized sodium.

Please understand I'm not trying to offend anyone. I'm just trying to learn more about mold and mildew since this is the stuff I deal with 9 times out of 10 everytime I get a call in my area.

Thanks

Richard R.

 

[Harold Brantley]

Mark, since you are already using sodium hypochlorite in your house wash solution, I would look at the actual % you are putting on the surface. I apply about 1.4% to the surface and it works fine. I live in your area and have the same weather conditions. Calculate this percent starting with the concentration of the chlorine then how much water you add to this, then the dilution going thru the chemical injector or x-jet. If this still gives you a good percentage of chlorine, I would wonder how old the chlorine is because it does loose its strength. I use 12% chlorine, use it within a month, keep it air tight and out of the sun. If this has only happened twice then this may be the most reasonable answer. Don't go too high on the % chlorine or you will start to harm the vegetation.

I don't like hot water for residential cleaning, nor high pressure. If your chemicals do their job a low pressure rinse from a good distance away is all that is necessary.

I agree with Richard, I too would like to see Bates information source.

Gasman, let us know what location you are in?

 

[sprayandclean]

Sodium / condensation

Sodium does attract moisture. Remember putting rice kernals in the salt shaker to keep the salt from turning into a lump? (before airconditioning for you youngsters). Damp Rid attracts moisture from the air to itself, I'm not sure what it's composition is , but it 'sucks' the moisture from the air until the 'cryatals are saturated, then you can force the moisture out of the crystals by heating in the oven at low temp, just as you can with those little bags of silica gel that come in packages of moisture sensative materials. (heat just over boiling point (220 degrees F) ie.force the liquid back to steam / water vapor.)

I have been washing houses/ cleaning mildew for 10 years. I work primarily in Charlottesville Va, where University of VA is located. I have had the luck of working for several chemists and micro-biologists, and have pursued their knowledge as it relates to our businesses.

On the mildew front, there is one common demonater needed for the formation of mildew.... water. 'Our' water is found in the form of condensation on buildings. Condensation forms when the surface is cooler than the dew pointof the air, which condenses the air bourne water vapor to turn back to liquid and hang on the cool surface of the building, then the airbourne bacteria land in the water film, and presto, you have a living micro-system. In time this happens over and over and you then get a visible 'growth' of mildew. (This 'growth' is actually many layers of the remains od bacteria, and their by-products.)

Why does sodium hypochlorite work so well removing mildew? (actually it removes the color, which is the start of an oxidation process which breaks down the mildew).... oxidation is the key here, the sodium hypochlorite chemically 'burns up' the mildew, along with any other organics found on the surface. This is why you also get rid of (oxidize) mold and algae on the surface of concrete vinyl etc. If you do not rinse off the film left by the oxidation process, this film will act as a host which holds the condensation and the bacteria. This is why unrinsed houses 'grow' the mildew back quicker than new surfaces, and newly painted surfaces.

Hot water works better for cleaning because the heat increases the speed of the molecular reaction. Have you ever tried cleaning mildew in the cold? Everything takes longer doesn't it??? Rinsing with hot water also breaks the residue of the now oxidized mildew loose quicker and more completely than cold water. Hve you ever washed dishes? Ever tried to rinse soap film off of dishes with cold water? Does't work too well does it?

Using a low pressure hot water sysem works for me. It is fast and efficent. When I was using cold water the houses got clean, and looked good, but they stay cleaner longer with hot water.
I actually guarantee 'my' houses will stay clean 2 years, in writing. Oh, I almost forgot... hot water gets windows clean too... no streaks or spots.

Bates McLain
Spray and Clean

www.sprayandclean.com

 

[csoldier]

Bates, what type of mixture do you use for house wahing? What type of pressure do you rinse with? I clean plenty of old houses with wooden window fromes and casings. High pressure definitely cannot be used due to leakage. Any advice?
Thanks and God bless!!!!!
Mark, La.

 

[Richard R.]

Bates,

I think I understand, although I'm not real sure I totally agree with the theory.
Rice in salt technigues are just images of our ancient myths like many of the same myths we share from years ago from our Grand Parents.
I suppose these techniques may really work, but while growing up I never used them because the rice seemed to get in the way of the holes that delivered my salt and slowed down speed of the output.
Actually, all jokes aside, it seems simular to the technique used to keep the moisture out of sugar by inserting crackers inside a sugar sack or container, also used with other types of granular substances.
I'm not sure that the rice in salt and cracker in sugar theory is exactly the right analagy to use for this theory, but if it is, it brings up a few more interesting views.
I believe if the micro-biologists and chemists at the University of Charlottesville, Va., would admit it, they would tell you that the culprit of moisture is not necessarily that salt, sugar and other granular substances attract moisture, but rather that the moisture is caused by the storage method and the environment in which these products are stored prior to use.
If you will notice, there are times you or your wife may get a bag of sugar or salt from the grocery store that contain lumps and some you buy do not. This I believe is caused by the method in which it was stored at the factory or maybe something that happened during transportation. This seemed to have prompted our ancestors to put rice and or crackers in their salt and sugar. It did not necessarily assist in keeping the salt from attracting moisture, rather it helped to absorb the moisture already in the product or moisture that occurred while setting in the RH. In other words, your kitchen and bathroom atmosphere changes so many times and so rapidly in a day and while being closed up, they sweat due to the changing of inward temperature inside the containers. Have you ever seen mold and mildew grow on salt?

Now with all this said, I have to say that I can not rule out your entire theory. Especially if your guaranteeing your clients a two year warranty against reoccurring dirt mold and mildew.

Maybe you could share with us exactly what you use in your mix that would help us in doing a better job. I respect trade secrets, but you can't blame me for trying.
As for the hot water rinse, I totally agree with you on that point. I also get better results while using a low pressure heated rinse. I just can't garantee the two years satisfaction from reoccurring mold and mildew in my area and I use a very stout mixture of Sodium hypochlorite and sodium hydroxide.

Thanks very much for your information.
It is very interesting.

Richard R.

 

[Harold Brantley]

Thanks Bates for the good information. I'll still stay with cold water as a personal preference. I would use hot water if I thought I was not killing and removing the mildew and dirt. I get a year plus in our gulf coast weather conditions before recleaning is needed.

Everyone has to use what works for them. The sharing of information on this board allows those who are having problems in some aspect of their cleaning to read about and try new chemicals, methods and equipment that has been successful for others. No one knows it all, but the sharing allows each of us to become smarter in our pursuit of excellence. Glad to have you join us Bates. Welcome.

 

[PUREPOWER]

Mark,

I do alot of painting as well as pressure washing. There are times that an exterior painter has not prepped the surface properly before recoating. This may be your problem...If the painter HAS painted over mold and/or mildew...it will return at an alarming rate. I am working on an exterior paint job in the suburbs of Pittsburgh as we speak, this is the situation I am dealing with. After washing, the house turned again in three days on the wood surfaces only. I stripped an area of the last layer of paint(actually by accident,I got too close when spraying and peeled the paint), and that area has remained white. Sherwin-Williams has agreed with the theory of improper prep by the last painter. The house was painted only two years ago. So, basically, any affected areas have since been stripped.

I do use the same mixture for vinyl and painted wood surfaces to wash with, Completely different with aluminum siding. Never had any problems with returning mildew, with the exception of the previously stated situation.

Just some food for thought.

I really think the question you originally posed has not been answered. I use liquid Tide also and pool chlorine (10.5%) solution, I also add a little potassium hydroxide with d'limonene into my mix. Streaks the hell out of windows if not rinsed well, but I have found this mix effective for my applications.

Bottom line...it may not have been your cleaning procedure, it may have been an existing condition


Jordan[sb]

 

[gasman]

Richard....
Re-read Bates posts. Like I said the bleach will whiten out the algae and mildew and make a surface apear clean if all you do is spray on a bleach mixture with an x-jet. Untill you pressure rinse or brush this reidue left behind off, It will return shortly. I hear of guys cleaning houses in less than 2 hours, one man, x-jet, etc. but they are not in my book cleaning untill they take time and rinse with a pressure fan spray 6 to 8 inches off surface.

 

[Richard R.]

Gasman,

Your right, I guess I misunderstood the context.
I'm glad there are people out their like You and Bates that spend enough time to research and do it right.
I hear a lot of people talk about the guys that just spray water on the house, collect their money and leave. I live in a town where this business hasn't caught on as well as it has in others, so I haven't really seen people like that here.

It's obvious that you and Bates are proffessional surface cleaners and very knowledgeable about this business.
Fortunately we have a lot of great guys on this BB and I'm sure glad to see You and Bates joining it.

Thanks for setting me straight.
I look forward to your other posts.

Richard R.

 

[Harold Brantley]

Gasman, please let us know your location. Your method of rinsing doesn't reflect what I find to be true in the hot, humid south along the Gulf Coast. In your location, bleach may only whiten the mildew and therefore be necessary to pressure rinse at 6" to 8" from the surface. That is not the case here.

My wash solution which contains about 1.4% chlorine, applied to the house surface with low pressure will turn the green mildew to a yellowish color and start running down the surface. After two or three minutes of dwell time, a low pressure fan rinse from 5' to 15' away will remove all of the killed mildew and dirt on the surface on a one story house with gables. For two story houses with gables, I switch to a 0 deg nozzle but still with low pressure.

How do I know if I have killed and removed all of the mildew? My way of judging that is that I wash several hundred repeat customers a year that go 12 to 15 months before recleaning is necessary. If they were turning green with mildew after 2 or 3 months, I would have those customers phoning to tell me about it.

Again my results may be very location sensative. Our mildew grows very rapidly with high temperature and humidity, but does come off pretty easily with the right chemicals and procedures. If I had to use Gasmans' high pressure, close up rinse in this area, my prices would probably have to double, especially on two story houses with gables.

What about others, does your location require high pressure and a close up rinse to stay clean for one year?