My uncle lives in Upstate New York. His barn was built in 1803. He has attempted to paint but the paint always peels off. He thinks it might have a white wash on it but is unsure. Should he power wash or sandblast the barn to remove the old paint

We moved into a home where smokers previously resided. We hired a professional painter to prime with Kilz 2 throughout the entire house. In the large majority of the house the Kilz was put on very thin, to the point that the yellow color from the nicotine residue is seeping