Q. Our 25-year-old house was repainted two years ago, six years after the previous repainting. Now, all the newly painted wood and ironwork are black with mildew. Why? There was no evidence of mildew on the old surface. The painting contract called for the best oil-base paint. Now we'll have to repaint, we feel. How do we get rid of the mildew? Mrs. Cosette W. MacIntire Wayzata, Minn.
A. Mildew is an act of nature that is difficult to predict. Nobody really knows just why it decides to land on one area and not another. Needless to say, mildew requires moisture to occur.
I suggest you mix one cup of household bleach, one-half cup of trisodium phosphate (TSP), and one gallon of warm water. Then go to work.
Thoroughly scrub the surface with a soft- to medium-bristle brush and allow the mixture to stay on the surface for about 15 minutes. Then rinse completely with clear water.
This process often will remove the mildew sufficiently to eliminate the need for a new paint job.
Should you decide that repainting is indeed necessary, do so soon after you have scrubbed the walls with the above mixture. Wait for the walls to dry completely. Use a good-quality acrylic latex paint that cleans up with water.
If you do repaint, add to the paint an extra shot of Mildewcide (put out by Dow Chemical) or a similar product, after discussing it with your local paint expert.
We would not advise the reuse of an oil-base paint. Acrylic stands up better in all climates.