Most Seattle leases contain specific terms about whether the tenancy continues after the ending date, sometimes known as a holdover tenancy. If your lease had a specific ending date but neither you nor the landlord did anything to end the tenancy, then it became a month-to-month tenancy when you continued to pay the rent and the landlord continued to accept it. A month-to-month tenancy in Seattle is subject to the so-called "Just Cause" ordinance, which means that the landlord cannot terminate the tenancy unless the landlord has a good reason specified in that ordinance. A tenant's refusal to sign a new contract is not just cause for eviction, but some new rules can be promulgated by the landlord with 30 days' notice (RCW 59.18.140, linked after this answer). The difference between "new rules" and a "new lease" can be a little fuzzy, but in general "rules" pertain to keeping noise down, cleaning up the laundry room, keeping clutter out of the common areas -- stuff like that. The full extent of new "rules" is unclear (to me, at least), but the landlord cannot impose a new lease on a month-to-month tenant by disguising it as "rules". Other lawyers on this site might have a better notion of the boundaries of new "rules", but the boundaries are no clearer to me now than they were 20 years ago.
You can terminate a month-to-month tenancy by at least 20 days' written notice ahead of the next rent payment date, but the landlord can't do the same unless the landlord has just cause. The landlord can ratchet the rent up in increments which are regulated by the City of Seattle, but cannot terminate the tenancy outright. If you want to leave without giving enough notice, you could be liable for the full next month's rent after you depart, but the landlord has a duty to try to re-rent and thereby mitigate the loss. The statute you refer to, RCW 59.18.220, would have applied if the landlord or you had enforced it, but when you both treated the holdover tenancy as month-to-month, it became month-to-month.
This answer is intended as a courtesy only, and does not constitute an attorney-client relationship between the attorney and the questioner.
Under RCW 59.18.220, the contract would be for a specific amount of time without any provision to automatically renew or convert to a month-to-month tenancy. Even without the language, by remaining in possession and paying rent the last two months, you may have formed a month-to-month tenancy.
RCW 59.18.200(1)(a) When premises are rented for an indefinite time, with monthly or other periodic rent reserved, such tenancy shall be construed to be a tenancy from month to month, or from period to period on which rent is payable, and shall be terminated by written notice of twenty days or more, preceding the end of any of the months or periods of tenancy, given by either party to the other.
I hope this helps get you started. Please let me know if you have any more questions.
This posting is for informational purposes only. It is not legal advice and does not establish an attorney-client relationship. <a title="Attorney Ryan A. Jacobsen" href="http://jacobsenlawoffice.com/about/">Ryan A. Jacobsen</a> | <a title="People | Property | Business" href="http://jacobsenlawoffice.com/">Jacobsen Law Office, P.S.</a><br /><b> <a title="People | Property | Business" href="http://jacobsenlawoffice.com/people/">People</a> | <a title="People | Property | Business" href="http://jacobsenlawoffice.com/property/">Property</a> | <a title="People | Property | Business" href="http://jacobsenlawoffice.com/business/">Business</a></b>