What is the correct dilution for Clorox to remove mildew from outside clapboard on a house? Thanks Greta
Correct Clorox Mix?
Jun 30, 2003
3 Replies
Not more than a cup per gallon of water. The mix should have some detergent added.
Hi Gretta
In the neighborhood of .04% sodium hypochlorite.
Using Clorox, you can no longer go by the 1 cup per gallon rule of thumb as Clorox sells both 3% and 5% sodium hypochlorite.
Often the off-brand versions are greater than 5.15% sodium hypochlorite and cost much less!
Then follow-up with a washdown using 'Soilax' or non-sudsing detergent.
Use algicide in your primer and in your paint on Northern exposed surfaces.
TTUL Gary
Let me be the first to apologize for Phisherman and Gary. Everything's a joke to them.
The traditional mixture for exterior walls, recommended by Sherwin-Williams and the North Carolina Extension Service, is 1 part bleach to 4 parts water. That would come out to 1.05% hypochlorite with the old 5.25% bleach and 1.2% hypochlorite the new 6% bleach.
I like to add 1/2 cup of baking soda for each cup of bleach. That makes the bleach stronger on mildew but milder on skin and clothes. Soda also lets you get good results with a more dilute bleach mixture.
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