What is the yellow stuff on the concrete ceiling?
See the photo. It is crawl space above an office. I think the ceiling is concrete. Do you see the yellow coloring? What is that? Mold? Efflorescence? Little bits of insulation (but how would they get to ceiling)? Something else? If mold, that's bad, right? If efflorescence, could that indicate an a ongoing moisture issue? Thanks.
- 15 Old House Features We Shouldn't Abandon
- 17 Tiny Bathrooms We Love
- 16 Designs for a Low-Cost DIY Coffee Table
- Insanely Easy 60-Minute Home Improvements
- 12 Sheds You Could Live (or Work) In
- Assembly Required: 15 DIY Kit Homes
- 30 Things Every Adult Should Know How to Do
- 10 Surprisingly Simple Woodworking Projects
- 7 Surprising Other Uses for Mayonnaise
- 9 Ways to Make Your TV Look at Home
- 9 Totally Amazing Mobile Home Makeovers
- 11 Lessons to Learn from AirBnB's Tiniest Homes
- 10 DIY Ways to Redo Your Wall—Without Paint
- 8 Smart Shoe Racks You Can Make Today
- 7 Easy Budget-Friendly Backyard Makeovers
- Worth It: 8 Renovations That Pay You Back
- 7 House Sounds Never to Ignore
- Watch These 10 Home Trends Take Off in 2015
- 11 Things Never to Keep in Your Bedroom
- 12 Places You Never Clean—But Should!