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Thread: OT: House paint and bleach?
06-14-2012, 07:46 PM #1
OT: House paint and bleach?
Paying extra for the anti-mildew additive doesn't seem to work. Can I add bleach to the paint myself? If so how much?
06-14-2012, 07:53 PM #2
Unless you are buying some cheap generic paint, they have mildewcides in them. Is this for interior / exterior? Exactly what problem are you trying to address that you think you need to add bleach?
06-14-2012, 08:22 PM #3
I live in a valley and the storms come from the SW and that end of the house has a mildew problem. As I stated earlier the additive doesn't seem to work. I may be paying for it and not getting anything, or not enough to do the job.
06-14-2012, 09:15 PM #4
For a killer before you paint, bleach is ok. You can also use Thymol dissolved in Methylated spirit. You can get Thymol from a food / fragrance industry wholesaler.
06-14-2012, 10:00 PM #5
Bleach doesn't mix with paint and its effects won't last. Like technocrat said, wash with bleach before you paint is ok.
The additives work, for a while. After that, wash with bleach--low pressure wash is fine, high pressure will damage stuff.
06-14-2012, 10:10 PM #6
" I live in a valley and the storms come from the SW and that end of the house has a mildew problem. As I stated earlier the additive doesn't seem to work. I may be paying for it and not getting anything, or not enough to do the job.'
That says that ventilation is not the problem. It is outside. The North side of my house also gets mold/mildew on the outside wall. I have pressure washed the vinyl siding, think I will try the low pressure bleach stuff this time.
Ralph, I take it you have a wooden house that needs repainted at intervals.
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06-15-2012, 06:14 AM #7
Ralph - If you are using a good quality paint like Sherwin Williams Duration and still have a mold problem on the SW side, my next question is how much shade is there? The more I learn, the more I dislike trees next to my house. If they aren't keeping roof and wall surfaces moist and causing mold growth, the roots are damaging things. Cut down 4 last year at my place.
06-15-2012, 09:50 AM #8
There is no such thing as good quality paint anymore. Today's paint is designed to meet gov't reg.s... suitability for purpose is a distant second consideration. Gov't reg.s are designed to protect stupid people from themselves, not about keeping paint on your house.
Bleach won't work as a long lasting mildewcide, because it doesn't leave anything toxic to organisms in the paint long term. In days of yore, the best house paints were formulated with white lead as pigment... now that's toxic. It also continually exposed new toxic material as it weathered away. The problem is, it's not only toxic to mold and mildew, but also to little kids who chew on window sills. Since of course people can't be responsible for keeping their kids from eating the building, the rest of us can no longer have mildew free paint.
Zinc compounds were also used for a while, but I suspect are no longer permissible.
Whatever is being sold as an anti-mildew additive these days I'm sure is perfectly safe, and will harm neither kids, or mildew.
Best course of action would seem to be to clean the existing with a strong bleach, I've used Mold_Clean from the people who make Bora-Care log structure preservative. Paint, then occasionally apply one of the spray-on house cleaners, such as Wet & Forget.
Sorry if I sound bitter... I'm in the midst of dealing with the exact same problem.
06-15-2012, 12:27 PM #9
The older acrylic paints used a mercury based anti-mildew agent. Your friends at the ePA outlawed same. The current stuff is simply not as effective. As above, bleach, dry, and paint with a Good quality material. Talk to the people at a name brand paint store, not a big box store. Of course they want to sell you a high priced paint, but just maybe that is what you need...
06-15-2012, 01:36 PM #10
Thanks for the reply's. There is no shade on that end just hot sun.
06-15-2012, 04:06 PM #11
Can't say I have ever seen mildew in direct sun... I thought the UV rays prevented that. Are you sure that's what it is? In any event, bleach will take care of it. My best results came from pressure washing with undiluted bleach right from the jug - bleach w/o the additives is what the gov uses for NBC cleanup, just a stronger concentration. Bleach from the super market is only like 5% anyway. Wear some kind of eye protection because it is strong enough to give them a burning sensation if the wind is in the wrong way - then let dry completely.
I had the mildew problem on the north side of a previous house and treated it as above - and doubled or tripled the number of vents along the bottom of the roof and also added them to the spaces where the roof overhung at the ends. Painted it with premium exterior latex and had no more problems.....
I did the whole house because the high pressure washer also removes a lot of the old chalked paint and let's the new coat adhere better. Of course, you still have to scrape, caulk, and all those other fun activities before painting again!
06-15-2012, 06:03 PM #12
George,my house and shop has vinyl siding and used to get mildew on one side. First I power washed the siding,then sprayed a 1x10 bleach and water solution on the sides that got mildew.Lasts for an entire year,maybe more.I use a pump sprayer ,garden type.
06-16-2012, 11:42 PM #13
that is my plan.
06-18-2012, 06:31 AM #14
Krud Kutter makes some good mildew killers, I would consider that before spraying bleach on my house.
06-18-2012, 07:19 AM #15
Bleach, in a "weed sprayer", sprayed on the white vinyl siding on the north side of my house seems to kill the black/green mildew that likes to form there. I spray it, and 10 minutes later it's gone.
And actually, when people painted there houses in years past the paint they'd use would "chalk" as part of it's aging process. As the paint chalked off there'd be a bright white surface. Not sure if paint these days does that or not.