Perhaps it's my German heritage, but we sweep our porch and sidewalks nearly daily. We power wash our concrete surfaces (walks, drive and garage, patio) in the spring and fall, and that makes quick work of the project, and that sounds like a good place to start. If you don't have a small power washer and don't want to make the $100 purchase or rent one, there are also hydro brooms -- you attach to a water hose -- that might help you out, along with some concrete cleaning compound (hardware store).

-Grainlady

This particular area is a northern exposure and it stays damp quite a bit of the time, especially this year The sun never gets to it and I think that may be part of the problem. I have never used a power washer before. Is it easy to handle?

Thanks,
Linda

I'm rather small in stature and can use out power washer. It's not a commercial model, but one made for home use. It's easy to use once you get the hang of it.

I can run our small power washer quite easily. If you've ever washed your car at a coin-op car wash, it's similar to the power wash wand.

You may need a special cleaning solution for the mold or moss, which is probably what the black substance is. Preferably a product which can be used with the power washer. You can also pre-treat the black spots by putting the cleaning solution in a bucket (follow the label instructions) and applying the solution with an old broom or brush. Just make sure anything you use is pet and plant friendly. Now that I think of it, there are also bottled products you could use. You attach the bottle to the garden hose and it will dispense the product that way, but without as much pressure as a pressure washer. You may have to use a broom or brush to get the tough spots. A good hardware store will be able to help you out.

Another suggestion if you do power wash, buy an inexpensive rain suit (pants and jacket). Use rubber bands at the ankles and wrists to hold them shut, and blast away without worrying about the spray-back getting your clothes wet. BTW, power washers use very little water.

-Grainlady