I've had my jackstands sink in when I lived in an apartment. and the jack left dents . If you did your garage in asphalt you would need some plywood squares to put undet them. When I built the new shop, 40 X 120 I was going to leave the back half gravel and use it for storage. My sons talked me out of it. They were going to come and help pour the floor but the three of them couldn't get the same day off so I bit the bullet and forked out the 7 G's to have it done in one day.