Hoping someone can point me in the right direction with an issue I am having with my house. The house was constructed in 1963 and the last exterior paint job was probably about 8 years ago. In various places on the exterior bubbles in the paint are appearing. Behind the bubbles is a powdery white substance that easily scrapes off down to the cement (sorry if "cement" is incorrect term). Here's a picture of a bubble before I open it up: Here's a couple pictures of the bubble after peeling away the paint: And, finally, here's a picture of the area with the white powdery substance scraped away: I would like to correct this issue before I get into real trouble with damage but need to know what its doing before I can correct it. Thanks in advance for your help.