We put down a new pressure-treated pine deck about a year and a half ago and waited a year to stain it. We used Porter semi-transparent stain. Now we suddenly are seeing white spots and streaks on many areas of the deck. It is nothing we have done or spilled; some areas are at far ends of the deck where we never even go or walk.

Porter said it probably was sap coming through the pine and to try rubbing it off with turpentine. That seemed to work, but within a few days when it rained again the white spots and streaks are all back.

Can one of you experts tell us what is causing this and how to get rid of it, please?!! We are in Atlanta and the weather has been cool and rainy if that makes a difference. Thanks.