Hi all, We just bought a house and the previous owner stained the concrete floors in kitchen and laundry room areas. We have a dog and just noticed what appears to be spots on the concrete from where he drinks out of his water bowl and drools/splashes around the bowl. These are grayish color, I am guessing from the hard water and/or nasty stuff in dog drool! This leads me to believe the previous owner may have stained, but never sealed, the concrete. I'm going to try to contact them and find out. So first question, is there any way to remove the spots that are already there - would vinegar or something like that help or make it worse? Second question, is there anything tricky we should know if we want to go ahead and seal (or re-seal) the floor to prevent further water spots? Any easy DIY products we could just mop on? Thanks in advance!

I'm considering buying a building lot. the lot has an existing poured concrete foundation on it that was poured 10 years ago but has never been built on. it has been backfilled and was inspected and ok'd to pour and ok'd to backfill 10 years ago by the town's building official. they did not pour the slab floor, it is filled with rock up to the footings. I know the contractor that poured the foundation is a very reputable company with an excellent reputation. I'm concerned that because it has not been built on and no framing to hold it out, that the walls may have become compromised over the 10 years. question is: other than placing a level on the foundation walls to see if they have been pushed in, is there any way to test it to make sure it is structurally sound? There are two cracks in the wall, one in a corner and the other in a section that should be very strong (where there is a U shape in the wall. the walls still appear plumb. second question: I want to raise the foundation 2 feet for a finished basement. can that be done without compromising the structural integrity of the foundation?