Salt leaching through cement

Sorry, but that's a natural phenomena. Blame it on nature. I recommend that you simply wait for dry weather then power wash again. Then paint the surface with a water resistant sealer. Talk to an expert at Home Depot or OSH for the right sealer or paint. All cement will weep salt if it doesn't have a moisture barrier.

Efflorescence! Salts in the concrete and mortar surfacing from moisture. Apply concrete sealer after cleaning and removing.

thank you. Any recommendations on how to clean.

The first step in removing efflorescence is to vigorously rinse the concrete with water. If you are working with an outdoor surface, you can carry out this step with a garden hose. However, if the surface you are cleaning is located indoors, this process can be carried out with a spray bottle filled with water. Once you've thoroughly soaked the spot, put on your goggles, gloves, and a paper breathing mask; then, proceed to scrub the infected areas with a wire brush or scrub brush. For efflorescence that is relatively fresh, this step may ultimately constitute the entire cleaning process. If a fair amount of efflorescence remains after you've carried this out, you'll need to proceed with the next step. Having thoroughly rinsed your concrete and removed any fresh efflorescence deposits, you may now proceed to purge any caked-on deposits. Start by combining white wine vinegar and warm water in an empty spray bottle. Seal the bottle and shake it until your cleaner has taken shape. This highly effective, homemade solution will prove invaluable in ridding your surface of efflorescence. Once you've successfully produced a cleanser, spray it onto any deposits and allow it to set in for several minutes. Use your wire brush or scrub brush after to vigorously clean the troubled areas. Efflorescence that has had a good deal of time to adhere to the concrete may require you to put forth a considerable amount of elbow grease. Furthermore, you may need to apply your cleaner multiple times before you can fully purge all the efflorescence. Seal the concrete with a masonry sealer once the cocrete is completely dry -- at least two or three days. Follow the product instructions for application. The sealer helps prevent future efflorescence and other problems.

Good luck and keep us posted!

Thank you for the detailed explanation. I appreciate your answer and will be attacking this soon!

Good info. Thank you. I have no patience. Lol.