Q. Can you wash with a pressure washer a deck or the outside walls during the nine days?

A. Horav Shlomo Miller’s Shlit”a opinion is that the Nine Days should be dedicated essentially to the mourning of the Bais Hamikdosh and what we should do to bring about the Geula. Having said that, if there is a need to pressure wash a deck or outside walls (as in a cottage) it is permitted since it is not included on the laundering prohibition.

(See also question 337 in this forum permitting washing a car during the Nine Days)

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a.