Can I file a construction lien for pressure washing?

If the scope of your work was simply pressure washing, then I do not think you've met the "improvement" requirement of Washington's lien statute, and therefore, should not file a construction lien. To put things in the context of cleaning, a Washington appellate court held that where a trucking company removed contaminated soil from a gas station--despite the seemingly improving nature of removing contaminated soil from the property--the company's work was not an improvement under Washington's lien statute. Therefore, the trucking company could not prevail on its lien claim.

I would think a court would have difficulty including pressure washing as lienable work. If you do decide to proceed, however, you should be aware that you must file your claim of lien within 90 days of your last day of work.

Finally, keep in mind that you still have a breach of contract claim. Depending on the value of the work, you might consider small claims court or district court, as opposed to filing an action in superior court.

There are many issues raised in your question. You need to make sure that you provided all the required "pre-lien notice" to the owner and management company, that they were the "construction agent" for the owners of the property, and that you performed construction services that for "improvement of the property." "Improvement" is a term of art with liens and pressure washing may not qualify. Also, if the work was completed in early July, your right to file a lien is fast approaching if not passed. The risk to you of filing a lien that is not valid for failure of any requirement listed above (and others) is that you could be liable for a "frivolous lien" and have to pay attorneys fees to the owner for having it removed.

If your claim is less than the requisite amount for small claims, your best bet may be to seek remedy there. Attorneys are not allowed at small claims court. Otherwise, you may want to consult an attorney to help you assess your options.