Thank goodness, we have a full time maintenance man! We are very fortunate. He cleans the doors as he cleans the vacated units. When he has time, we have him clean the doors of our good customers for customer retention. Beyond that, we pray for rain.

This has been the one thing that has been driving me crazy. From time to time, we get the hose out and wash a row of doors. We've had a professional who comes along with his machine and cleans the doors, but it doesn't get the grit off, so we have stopped that.

There was conversation with the professional guy about adding something to the water to get rid of the grid, but he advised against it because the solution would leave marks on the concrete.

I look forward to a solution for this problem. We even tried waxing them, tried using a (too) expensive cleaner specifically for the doors. I wondering if we wax them when they are new and hose them frequently if the is the solution. Door manufacturers, what's the answer?