Correct Clorox Mix?

[Greta]

What is the correct dilution for Clorox to remove mildew from outside clapboard on a house? Thanks Greta

[Phisherman]

Not more than a cup per gallon of water. The mix should have some detergent added.

[Gary V. Deutschmann, Sr.]

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

[Lloyd Randall]

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.