“How old is the concrete? Is it white? Has it been sealed?
The reason we ask these questions is because occasionally swirls or marks can appear when concrete is cleaned… especially if the concrete is new or has been improperly installed or a water base sealer was used on the surface. In the unlikely event that marking should occur, of course our people have been instructed to stop as soon as marking becomes evident… but you should understand that we are not responsible for marking of the concrete resulting from cleaning.”