This is an external facing wall. There's brick on the outside. I'm noticing the wall surface is getting "bubbly." I peeled away the very brittle wall surface and found this. This wall faces south. Located in Denver, Colorado. House is approximately 50 years old. No evidence of insects or other animals inside nor out. The little brown dot material doesn't brush away.
We have just noticed this happening in the past few months. Help?
We have just noticed this happening in the past few months. Help?