Crystals on Basement walls

[Moe]

I recently bought a house that is about 50 years old. The previous owners had finished about half of the basement. Today I ripped some of the walls down. There was sheet rock with studs behind them, with insulation. I noticed some type of white crystals on the walls. When I touched it it flaked off. What is this stuff. Is it dangerous?

My house is in Long Island, NY.

Other questions:

I would like to refinish the basement but there is mold, and dirt on the walls (As well as this crystal stuff). What is the best way to clean the walls? Should I paint them with dry-lock? What about a vapor barrier? Same with the floors?

TIA

[stevea]

I would recommend that you can Basement Systems, Inc. at 1-800-541-0487 and ask for a free inspection of your basement. They will give you free advice as to what you need to do.
Pioneer Basement Systems only services the Massachusetts and RI area.

Due to your questions someone would need to view the problem in order to make recommendations. I hope this helps.

Steve